Oxsoralen-Ultra

Photosensitizing Agents
Sensitizers used in Photodynamic and Radiation Therapy

Take methoxsalen soft gelatin capsules with food or low-fat milk approximately 2 hours prior to ultraviolet light treatment.

Extracorporeal dosage (Uvadex)
Methoxsalen 20 mcg/mL solution is used in combination with the CELLEX photopheresis system; consult the photopheresis system operator's manual prior to use.
Each methoxsalen treatment involves collection of leukocytes, photoactivation, and reinfusion of photoactivated cells.
Do NOT directly inject methoxsalen solution into patients.
Preparation
Do NOT dilute methoxsalen solution.
Draw the appropriate amount/volume of methoxsalen solution for the treatment dose into a plastic syringe; immediately inject into the photoactivation bag.
Methoxsalen solution may adsorb onto PVC and plastics; therefore, only use photopheresis procedural kits supplied for use with the instrument.
Discard any solution that is not used during the procedure; vial is for single use only.
Storage in a plastic syringe: discard contents if not used within 1 hour.

Only a physician should apply the lotion to a patient. Never dispense the lotion to a patient.
To avoid photosensitization and possible burns, use a finger cot or rubber glove when applying the lotion to a patient.
Lotion should only be applied by a physician to a small, well-defined area of vitiligo. Preferably, application of the lotion should only be to lesions that can be protected by clothing or a sunscreen from subsequent exposure to radiant UVA; suitable covering of the application area or topical sunblock application to the application area should follow the therapeutic UVA exposure. If the lotion is applied to the hands or face, instruct the patient to keep the treated areas protected from light by use of protective clothing or sunscreening agents. The application area may be highly photosensitive for several days. A severe burn injury may occur if the application area is exposed to additional UV or sunlight.

new primary malignancy / Delayed / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
pulmonary embolism / Delayed / Incidence not known
thrombosis / Delayed / Incidence not known
thromboembolism / Delayed / Incidence not known

hypotension / Rapid / 1.0
bullous rash / Early / Incidence not known
cataracts / Delayed / Incidence not known
erythema / Early / Incidence not known
depression / Delayed / Incidence not known
edema / Delayed / Incidence not known

nausea / Early / 0-10.0
pruritus / Rapid / 10.0-10.0
infection / Delayed / 10.0-10.0
dysgeusia / Early / 0-1.0
rash / Early / Incidence not known
folliculitis / Delayed / Incidence not known
skin hypopigmentation / Delayed / Incidence not known
miliaria / Delayed / Incidence not known
vesicular rash / Delayed / Incidence not known
urticaria / Rapid / Incidence not known
photosensitivity / Delayed / Incidence not known
insomnia / Early / Incidence not known
anxiety / Delayed / Incidence not known
dizziness / Early / Incidence not known
headache / Early / Incidence not known
malaise / Early / Incidence not known
muscle cramps / Delayed / Incidence not known

Administration of methoxsalen for extracorporeal administration requires an experienced clinician who has special competence in the diagnosis and treatment of cutaneous T-cell lymphoma and who has special training and experience in the CELLEX photopheresis system; consult the operator's manual before using this product. Oral methoxsalen with UV radiation should be used only by clinicians trained in the diagnosis and treatment of psoriasis and vitiligo and who have experience in photochemotherapy.

Oral methoxsalen is contraindicated in patients who have melanoma or a history of melanoma and in patients with invasive squamous cell carcinomas. Because pre-existing erythema may obscure observations of possible treatment-related phototoxic erythema, monitor patients with erythrodermic psoriasis closely. Methoxsalen therapy may cause a new primary malignancy such as skin cancer; monitor patients for the development of skin tumors. Additionally, patients with a history of basal cell carcinoma should be monitored closely. Previous cutaneous exposure to tar and UVB treatment, radiation therapy, or arsenic may increase the risk of developing skin carcinomas.

Oxsoralen-Ultra, UVADEX

Rx

Photosensitizing agent
Used for the palliative treatment of the skin manifestations of cutaneous T-cell lymphoma in conjunction with photopheresis (as a solution for extracorporeal administration); soft gelatin capsules in conjunction with ultraviolet radiation used for the symptomatic control of psoriasis
Patients should avoid UV or sunlight exposure during and for 24 hours after therapy

Calculate the dosage according to treatment volume as follows: treatment volume X 0.017 = mL of methoxsalen per treatment. Each treatment involves collection of leukocytes, photoactivation, and reinfusion of photoactivated cells; methoxsalen is injected into the recirculation bag prior to the photoactivation phase. Treatment is given on 2 consecutive days every 4 weeks for at least 7 treatment cycles (approximately 6 months). In patients who have an increased skin score (from baseline) at the fourth treatment assessment (at approximately 3 months), an accelerated treatment schedule may be administered consisting of 2 consecutive treatments every 2 weeks for a maximum of 20 cycles. Resume the regular treatment schedule if there is a 25% improvement in the skin score after 4 consecutive weeks on the accelerated treatment schedule. There is no clinical evidence of additional treatment benefit beyond 6 months or with a different schedule.

20 mg PO given with food or milk, 2—4 hours prior to measured periods of sunlight or UV radiation, 2—3 times weekly. Duration of exposure to sunlight or UVA is dependent upon number of exposures and basic skin color. Therapy should be on alternate days; never give on 2 consecutive days. Severe burns may result from doses greater than 0.6 mg/kg. This dosage should not be exceeded.

Apply to a well-defined area and then expose the area to UVA. Initial exposure time should be conservative and not exceed that which is predicted to be one-half the minimal erythema dose. Determine the treatment interval by the erythema response; generally once a week treatment or less is recommended. Pigmentation may begin after a few weeks, but significant repigmentation may require 6—9 months of treatment. Periodic retreatment may be necessary to retain all of the new pigment.

Administer the appropriate dose (as follows) with food or milk 2—3 times weekly; separate doses by at least 48 hours. For patients weighing < 30 kg administer 10 mg PO; for patients weighing 30—50 kg administer 20 mg PO; for patients weighing 51—65 kg administer 30 mg PO; for patients weighing 66—80 kg administer 40 mg PO; for patients weighing 81—90 kg administer 50 mg PO; for patients weighing 91—115 kg administer 60 mg PO; and for patients weighing > 115 kg administer 70 mg PO. Give Oxsoralen-Ultra 1.5—2 hours before or 8-MOP 2 hours before measured periods of high-intensity UVA exposure. If there is no response or only a minimal response after 15 treatments, the dosage of methoxsalen may be increased by 10 mg. The one-time increase in dosage may be continued for the remainder of the treatment course but should not be exceeded. When patients have achieved 95% clearing or a Grade 4 response (95% improvement with complete flattening of plaques including borders), they may be placed on a maintenance schedule. Once a week treatment, once every 2 weeks, once every 3 weeks, and then as necessary for flares is the recommended sequence. Adherence to each maintenance sequence step for at least 2 treatments is recommended unless erythema or psoriatic flare occurs.

†Indicates off-label use

Specific guidelines are not available; however, patients should be treated with caution, as methoxsalen undergoes significant hepatic metabolism.

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed. Although data are lacking in patients with varying degrees of renal impairment, no reduction of dose or prolongation of the time required to use UV light protection were reported in renal transplant recipients with poor renal function who have undergone photopheresis treatment with methoxsalen.

Abciximab: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Acetaminophen; Ibuprofen: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Adapalene: (Moderate) Use methoxsalen and adapalene together with caution; the risk of severe burns or phototoxicity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Adapalene; Benzoyl Peroxide: (Moderate) Use methoxsalen and adapalene together with caution; the risk of severe burns or phototoxicity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Albuterol; Budesonide: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Allopurinol: (Minor) Preclinical data suggests that allopurinol may decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Alpha interferons: (Moderate) Additive myelosuppressive effects may be seen when alpha interferons are given concurrently with other myelosuppressive agents, such as antineoplastic agents or immunosuppressives.
Alteplase: (Minor) Agents that decrease clotting, such as thrombolytic agents, could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Amlodipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amlodipine; Atorvastatin: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amlodipine; Benazepril: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amlodipine; Celecoxib: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amlodipine; Olmesartan: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amlodipine; Valsartan: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound. (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Anagrelide: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Anticoagulants: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Antithrombin III: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Apixaban: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Argatroban: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Aspirin, ASA; Dipyridamole: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Atenolol; Chlorthalidone: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Azelastine; Fluticasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Azilsartan; Chlorthalidone: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Beclomethasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Bendamustine: (Major) Consider the use of an alternative therapy if methoxsalen treatment is needed in patients receiving bendamustine. Methoxsalen may increase bendamustine exposure, which may increase the risk of adverse reactions (e.g., myelosuppression, infection, hepatotoxicity). Bendamustine is a CYP1A2 substrate and methoxsalen is a CYP1A2 inhibitor.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Use methoxsalen and methylene blue together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Betamethasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Betrixaban: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Bivalirudin: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Budesonide: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Budesonide; Formoterol: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Budesonide; Glycopyrrolate; Formoterol: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Bupivacaine; Meloxicam: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as meloxicam could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Calcium-channel blockers: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Chlorothiazide: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Chlorpromazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Chlorpropamide: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Chlorthalidone: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Chlorthalidone; Clonidine: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Cholera Vaccine: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the live cholera vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to cholera bacteria after receiving the vaccine.
Ciclesonide: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Cilostazol: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Clevidipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Clopidogrel: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Codeine; Phenylephrine; Promethazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Codeine; Promethazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Corticosteroids: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Cortisone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Dabigatran: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Dalteparin: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Deflazacort: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Demeclocycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Desirudin: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Dexamethasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Diclofenac: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as diclofenac could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of diclofenac before and during photodynamic therapy may be advisable.
Diclofenac; Misoprostol: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as diclofenac could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of diclofenac before and during photodynamic therapy may be advisable.
Digoxin: (Moderate) Some antineoplastic agents have been reported to decrease the absorption of digoxin tablets due to their adverse effects on the GI mucosa; the effect on digoxin liquid is not known. The reduction in digoxin tablet absorption has resulted in plasma concentrations that are 50% of pretreatment levels and has been clinically significant in some patients. It is prudent to closely monitor patients for loss of clinical efficacy of digoxin while receiving antineoplastic therapy.
Diltiazem: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Diphenhydramine; Ibuprofen: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Diphenhydramine; Naproxen: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as naproxen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of naproxen before and during photodynamic therapy may be advisable.
Dipyridamole: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Doxycycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Edoxaban: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Enoxaparin: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Eptifibatide: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Eravacycline: (Moderate) Use methoxsalen and eravacycline together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity. Prevention of photosensitivity includes adequate protection from sources of UV radiation and the use of protective clothing and sunscreens on exposed skin.
Ethotoin: (Major) Hydantoins may increase the clearance of methoxsalen. The mechanism may be due to phenytoin induction of hepatic metabolizing enzymes resulting in reduced methoxsalen serum concentrations.
Etodolac: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as etodolac could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of etodolac before and during photodynamic therapy may be advisable.
Felodipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Fenoprofen: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as fenoprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of fenoprofen before and during photodynamic therapy may be advisable.
Fezolinetant: (Contraindicated) Concomitant use of fezolinetant and methoxsalen is contraindicated due to the risk of increased fezolinetant exposure which may increase the risk of fezolinetant-related adverse effects. Fezolinetant is a CYP1A2 substrate; methoxsalen is a moderate CYP1A2 inhibitor. Concomitant use with another moderate CYP1A2 inhibitor increased fezolinetant overall exposure by 360%.
Fludrocortisone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Flunisolide: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Fluphenazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Flurbiprofen: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as flurbirprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of flurbirprofen before and during photodynamic therapy may be advisable.
Fluticasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Fluticasone; Salmeterol: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Fluticasone; Umeclidinium; Vilanterol: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Fluticasone; Vilanterol: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Fondaparinux: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Food: (Minor) Phototoxic dermatitis can result from contact with psoralen-containing plants/foods such as celery, fennel, limes, parsley, and parsnip. Contact exposure to such foods should be approached with care during methoxsalen treatment as in theory such exposure might increase the likelyhood of a skin reaction. Follow all directions of the manufacturer to avoid untoward methoxsalen-induced photoreactions.
Formoterol; Mometasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Fosphenytoin: (Major) Hydantoins may increase the clearance of methoxsalen. The mechanism may be due to phenytoin induction of hepatic metabolizing enzymes resulting in reduced methoxsalen serum concentrations.
Glimepiride: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Glipizide: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Glipizide; Metformin: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Glyburide: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Glyburide; Metformin: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Griseofulvin: (Moderate) Use methoxsalen and griseofulvin together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Heparin: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Hydantoins: (Major) Hydantoins may increase the clearance of methoxsalen. The mechanism may be due to phenytoin induction of hepatic metabolizing enzymes resulting in reduced methoxsalen serum concentrations.
Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Hydrocodone; Ibuprofen: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Hydrocortisone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Moderate) Use methoxsalen and methylene blue together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Ibuprofen: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Ibuprofen; Famotidine: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Ibuprofen; Oxycodone: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Ibuprofen; Pseudoephedrine: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ibuprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ibuprofen before and during photodynamic therapy may be advisable.
Indapamide: (Moderate) Indapamide may cause photosensitivity and may increase the photosensitization effects of drugs like photosensitizing agents used in photodynamic therapy. Prevention of photosensitivity includes adequate protection from sources of UV radiation (e.g., avoiding sun exposure and tanning booths) and the use of protective clothing and sunscreens on exposed skin.
Indomethacin: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as indomethacin could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of indomethacin before and during photodynamic therapy may be advisable.
Interferon Alfa-2b: (Moderate) Additive myelosuppressive effects may be seen when alpha interferons are given concurrently with other myelosuppressive agents, such as antineoplastic agents or immunosuppressives.
Interferon Alfa-n3: (Moderate) Additive myelosuppressive effects may be seen when alpha interferons are given concurrently with other myelosuppressive agents, such as antineoplastic agents or immunosuppressives.
Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Isradipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Ketoprofen: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ketoprofen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ketoprofen before and during photodynamic therapy may be advisable.
Ketorolac: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as ketorolac could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of ketorolac before and during photodynamic therapy may be advisable.
Lesinurad; Allopurinol: (Minor) Preclinical data suggests that allopurinol may decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Levamlodipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Meclofenamate Sodium: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as meclofenamate could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of meclofenamate before and during photodynamic therapy may be advisable.
Mefenamic Acid: (Major) Preclinical data suggest agents that inhibit prostaglandin synthesis such as mefenamic acid could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of mefenamic acid before and during photodynamic therapy may be advisable.
Melatonin: (Major) Caution should be exercised in patients on methoxsalen therapy (5- or 8-methoxypsoralen or 5-MOP and 8-MOP), which increases melatonin levels by inhibiting its metabolism. Methoxsalen is a potent CYP1A2 inhibitor in vitro.
Meloxicam: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as meloxicam could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Moderate) Use methoxsalen and methylene blue together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Methotrexate: (Major) Methotrexate may increase the photosensitizing effects of photosensitizing agents used for photodynamic therapy.
Methyclothiazide: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Methylene Blue: (Moderate) Use methoxsalen and methylene blue together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Methylprednisolone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Metolazone: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Minocycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Mometasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Nabumetone: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as nabumetone could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of nabumetone before and during photodynamic therapy may be advisable.
Naproxen: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as naproxen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of naproxen before and during photodynamic therapy may be advisable.
Naproxen; Esomeprazole: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as naproxen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of naproxen before and during photodynamic therapy may be advisable.
Naproxen; Pseudoephedrine: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as naproxen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of naproxen before and during photodynamic therapy may be advisable.
Nicardipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Nifedipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Nimodipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Nisoldipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound. (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Olopatadine; Mometasone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Omadacycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Oxaprozin: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as oxaprozin could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of oxaprozin before and during photodynamic therapy may be advisable.
Peginterferon Alfa-2a: (Moderate) Additive myelosuppressive effects may be seen when alpha interferons are given concurrently with other myelosuppressive agents, such as antineoplastic agents or immunosuppressives.
Peginterferon Alfa-2b: (Moderate) Additive myelosuppressive effects may be seen when alpha interferons are given concurrently with other myelosuppressive agents, such as antineoplastic agents or immunosuppressives.
Pentosan: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Perindopril; Amlodipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Perphenazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Perphenazine; Amitriptyline: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Phenothiazines: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Phenytoin: (Major) Hydantoins may increase the clearance of methoxsalen. The mechanism may be due to phenytoin induction of hepatic metabolizing enzymes resulting in reduced methoxsalen serum concentrations.
Pioglitazone; Glimepiride: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Piroxicam: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as piroxicam could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of piroxicam before and during photodynamic therapy may be advisable.
Platelet Inhibitors: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Porfimer: (Major) Avoid coadministration of porfimer with methoxsalen due to the risk of increased photosensitivity. All patients treated with porfimer will be photosensitive. Concomitant use of other photosensitizing agents like methoxsalen may increase the risk of a photosensitivity reaction.
Prasugrel: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Prednisolone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Prednisone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Prochlorperazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Promethazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Promethazine; Dextromethorphan: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Promethazine; Phenylephrine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Reteplase, r-PA: (Minor) Agents that decrease clotting, such as thrombolytic agents, could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Retinoids: (Moderate) Use methoxsalen and retinoids together with caution; the risk of severe burns/phototoxicity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Riluzole: (Moderate) Coadministration of riluzole with methoxsalen may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and methoxsalen is a CYP1A2 inhibitor.
Rivaroxaban: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Ropeginterferon alfa-2b: (Moderate) Additive myelosuppressive effects may be seen when alpha interferons are given concurrently with other myelosuppressive agents, such as antineoplastic agents or immunosuppressives.
Sarecycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
SARS-CoV-2 (COVID-19) vaccines: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the SARS-CoV-2 virus vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to SARS-CoV-2 virus after receiving the vaccine.
Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
St. John's Wort, Hypericum perforatum: (Major) St. John's wort has been reported to increase the phototoxicity associated with photosensitizing agents used in photodynamic therapy. Although interactions have not been reported, in theory it is possible that additive photosensitizing effects may result from the concomitant use of St. John's wort with other photosensitizing drugs.
Sulfacetamide: (Moderate) Sulfonamides may cause photosensitization and may increase the photosensitizing effects of photosensitizing agents used during photodynamic therapy.
Sulfacetamide; Sulfur: (Moderate) Sulfonamides may cause photosensitization and may increase the photosensitizing effects of photosensitizing agents used during photodynamic therapy.
Sulfonamides: (Moderate) Use methoxsalen and sulfonamides together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Sulfonylureas: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Sulindac: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as sulindac could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of sulindac before and during photodynamic therapy may be advisable.
Sumatriptan; Naproxen: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as naproxen could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of naproxen before and during photodynamic therapy may be advisable.
Telmisartan; Amlodipine: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Tenecteplase: (Minor) Agents that decrease clotting, such as thrombolytic agents, could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Tetracycline: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Tetracyclines: (Moderate) Use methoxsalen and tetracyclines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Thiazide diuretics: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Thioridazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Thrombolytic Agents: (Minor) Agents that decrease clotting, such as thrombolytic agents, could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Ticagrelor: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Ticlopidine: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Tirofiban: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Tolazamide: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Tolbutamide: (Moderate) Additive photosensitization may be seen with concurrent administration of sulfonylureas and other photosensitizing agents.
Tolmetin: (Minor) Preclinical data suggest agents that inhibit prostaglandin synthesis such as tolmetin could decrease the efficacy of photosensitizing agents used in photodynamic therapy. Avoidance of tolmetin before and during photodynamic therapy may be advisable.
Trandolapril; Verapamil: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Triamcinolone: (Minor) Because systemically administered corticosteroids exhibit immunosuppressive effects when given in high doses and/or for extended periods, additive effects may be seen with other immunosuppressives or antineoplastic agents.
Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Trifarotene: (Moderate) Use methoxsalen and trifarotene together with caution; the risk of severe burns or phototoxicity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Trifluoperazine: (Moderate) Use methoxsalen and phenothiazines together with caution; the risk of severe burns/photosensitivity may be additive. If concurrent use is necessary, closely monitor patients for signs or symptoms of skin toxicity.
Tuberculin Purified Protein Derivative, PPD: (Moderate) Immunosuppressives may decrease the immunological response to tuberculin purified protein derivative, PPD. This suppressed reactivity can persist for up to 6 weeks after treatment discontinuation. Consider deferring the skin test until completion of the immunosuppressive therapy.
Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
Verapamil: (Minor) Preclinical data suggest that calcium-channel blockers could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Verteporfin: (Moderate) Use caution if coadministration of verteporfin with methoxsalen is necessary due to the risk of increased photosensitivity. Verteporfin is a light-activated drug used in photodynamic therapy; all patients treated with verteporfin will be photosensitive. Concomitant use of other photosensitizing agents like methoxsalen may increase the risk of a photosensitivity reaction.
Vorapaxar: (Minor) Agents that affect platelet function, such as platelet inhibitors, could decrease the efficacy of methoxsalen when used during photodynamic therapy.
Warfarin: (Minor) Agents, such as anticoagulants, that decrease clotting could decrease the efficacy of photosensitizing agents used in photodynamic therapy.
Ziprasidone: (Moderate) Medications that may cause additive photosensitization when used with ziprasidone include methoxsalen. Patients should limit sunlight and ultra-violet exposure whenever possible, and use proper UV precautions to protect the skin.

Methoxsalen/Oxsoralen-Ultra Oral Cap: 10mg
UVADEX Extracorporeal Sol: 1mL, 20mcg

For vitiligo, 0.6 mg/kg PO qod; For psoriasis, 20 mg PO qod for patients < 30 kg, 30 mg PO qod for patients 30—50 kg, 40 mg PO qod for patients 51—65 kg, 50 mg PO qod for patients 66—80 kg, 60 mg PO qod for patients 81—90 kg, 70 mg PO qod for patients 91—115 kg, and 80 mg PO qod for patients > 115 kg for either hard gelatin capsules or soft gelatin capsules; Maximum dosage limits not established for topical therapy.

For vitiligo, 0.6 mg/kg PO qod; For psoriasis, 20 mg PO qod for patients < 30 kg, 30 mg PO qod for patients 30—50 kg, 40 mg PO qod for patients 51—65 kg, 50 mg PO qod for patients 66—80 kg, 60 mg PO qod for patients 81—90 kg, 70 mg PO qod for patients 91—115 kg, and 80 mg PO qod for patients > 115 kg for either hard gelatin capsules or soft gelatin capsules; Maximum dosage limits not established for topical therapy.

Maximum dosage limits not established for topical therapy; systemic treatment is not recommended.

Not recommended.

Not recommended.

Mechanism of Action: When methoxsalen (psoralen, P) is activated by long wavelength ultraviolet radiation (UVA), it is a potent erythemogenic, melanogenic, and cytotoxic therapy. The strongest activity occurs in the UVA range of 320—400 nm. Skin reactivity to UVA (320—400 nm) radiation is markedly enhanced by the presence of methoxsalen. The exact mechanism of action of methoxsalen with epidermal melanocytes and keratinocytes is not known. The reaction of methoxsalen with DNA is better understood. Upon photoactivation, methoxsalen conjugates with DNA and forms monofunctional (binding to a single strand) and bifunctional (cross-linking of psoralen to both strands) adducts. In addition, reactions with proteins may occur. Methoxsalen also acts as a photosensitizer. Exposure to UVA in the presence of methoxsalen can lead to cell injury and inflammation. The usual manifestation of this reaction is delayed erythema, which may not be seen for several hours and peaks 48—72 hours. The inflammation is followed over several weeks by repair that is characterized by increased melanization of the epidermis and thickening of the stratum corneum.In the treatment of vitiligo, it has been suggested that melanocytes in the hair follicle are stimulated to move up the follicle and repopulate the epidermis. In the treatment of psoriasis or T-cell lymphoma, the mechanism is most often assumed to be DNA photo damage and result decrease in cell proliferation but other vascular, leukocyte, or cell regulatory mechanisms may also play a role.

Methoxsalen is administered orally, topically, and extracorporeally. Methoxsalen is reversibly bound to serum albumin and is also preferentially taken up by epidermal cells. Methoxsalen is almost completely metabolized in the liver. Approximately 95% of the drug is excreted as metabolites within 24 hours.

The absorption of methoxsalen from the GI tract following oral administration is variable. Administration with food or milk increases absorption. Administration should remain consistent with food intake because the observed photosensitizing effect is likely related to the serum concentration of the drug. There is wide (6—15 fold) interpatient variability in peak serum concentrations after oral doses of methoxsalen. Maximum plasma concentrations occur 1.5—3 hours after oral administration of the hard-gelatin capsules (8-MOP) and may last up to 8 hours. Peak drug concentrations of the soft-gelatin capsules (Oxsoralen-Ultra) are obtained between 0.5—4 hours (mean 1.8 hours) following administration with 8 oz of milk. The overall extent of drug absorption is approximately 2-fold higher for soft-gelatin capsules as compared to the hard-gelatin capsules. Detectable methoxsalen concentrations were observed for up to 12 hours after a dose of the soft-gelatin capsules. Photosensitivity studies demonstrate a shortened time of peak photosensitivity (1.5—2.1 hours) for soft-gelatin vs hard-gelatin capsules (3.9—4.25 hours). In addition, the mean minimal erythema dose (MED, J/cm2) for soft-gelatin capsules is substantially less than that for hard-gelatin capsules. The half-life methoxsalen is approximately 2 hours.

The extent of absorption of topical methoxsalen is not known. Peak photosensitivity following topical administration occurs within 1—2 hours and can persist for several days.

Extracorporeal Route
Drug concentrations in the lens of the eye are comparable to serum concentrations. In an attempt to diminish interpatient variability and to increase exposure of white blood cells to the drug, methoxsalen sterile solution is injected directly into the buffy coat solution during photopheresis. This also results in a lower total dose of methoxsalen as compared to oral administration.

Methoxsalen may cause fetal harm if administered during pregnancy, based on data from animal studies. Methoxsalen soft gelatin capsules are listed as FDA pregnancy category C; methoxsalen for extracorporeal administration with photopheresis is listed as FDA pregnancy category D. Females of reproductive potential should avoid pregnancy during methoxsalen therapy. If methoxsalen is used during pregnancy or if pregnancy occurs during methoxsalen therapy, the woman should be apprised of the potential hazard to the fetus. Fetal toxicities (e.g., fetal death, decreased feal weight, and skeletal malformations/variations) were observed following administration of methoxsalen (80 to 160 mg/kg/day) in pregnant rats.

It is not known if methoxsalen is secreted in human milk. Due to the risk of serious adverse reactions in nursing infants, women should discontinue breast-feeding during methoxsalen therapy.