OXSORALEN-ULTRA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OXSORALEN-ULTRA (OXSORALEN-ULTRA).
Oxsoralen-Ultra (methoxsalen) is a psoralen derivative that, upon photoactivation by UVA radiation, forms covalent cross-links with DNA, thereby inhibiting DNA synthesis and cell division. It also suppresses cutaneous immune responses and reduces epidermal cell turnover.
| Metabolism | Oxsoralen-ULTRA undergoes extensive hepatic metabolism via cytochrome P450 enzymes (primarily CYP1A2 and CYP2A6). It is rapidly absorbed and has a half-life of approximately 2 hours. Excretion is primarily renal as metabolites. |
| Excretion | Primarily renal: 90-95% as metabolites within 24 hours; minimal biliary/fecal (<5%). |
| Half-life | 2 hours (terminal) with clinical context: elimination is rapid; no accumulation with q3-5d dosing. |
| Protein binding | 99% bound to albumin. |
| Volume of Distribution | Vd ~0.5 L/kg; indicates distribution into total body water with minimal tissue binding. |
| Bioavailability | Oral: well absorbed, bioavailability >80%. |
| Onset of Action | Oral: 2-4 hours to reach peak photosensitization. |
| Duration of Action | Oral: Photosensitivity lasts 8-12 hours; avoid UV/sun exposure for at least 24 hours. |
| Molecular Weight | 216.19 |
0.6 mg/kg orally as a single dose 2 hours prior to PUVA therapy, administered 3 times per week on non-consecutive days.
| Dosage form | CAPSULE |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (CrCl <30 mL/min) due to potential increased toxicity. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C). For moderate impairment (Child-Pugh class B), reduce dose by 50% and monitor liver function. |
| Pediatric use | Not recommended in children under 12 years due to lack of safety data. For children 12-18 years: 0.6 mg/kg orally 2 hours before PUVA, same frequency as adults. |
| Geriatric use | Start at low end of dosing range (0.4-0.6 mg/kg) and monitor for increased photosensitivity and renal function decline. |
| 1st trimester | Contraindicated due to teratogenic potential; avoid use. |
| 2nd trimester | Contraindicated; risk of fetal harm outweighs benefits. |
| 3rd trimester | Contraindicated; may cause neonatal phototoxicity or other adverse effects. |
Clinical note
Comprehensive clinical and safety monograph for OXSORALEN-ULTRA (OXSORALEN-ULTRA).
| Placental transfer | Crosses placenta; documented in animal studies and human case reports. |
| Breastfeeding | Excreted into breast milk; potential for severe adverse effects in nursing infant, including photosensitivity and carcinogenicity. Discontinue breastfeeding or avoid drug. |
| Lactation Rating |
■ FDA Black Box Warning
WARNING: Squamous cell carcinoma (SCC) and other skin cancers have been reported in patients treated with PUVA therapy. The risk is dose- and time-dependent, and increases with higher cumulative UVA exposure. Patients should be monitored for skin malignancies throughout treatment.
| Serious Effects |
Hypersensitivity to methoxsalen or other psoralensPorphyria cutanea tardaDiseases associated with photosensitivityMelanoma or history of melanomaInvasive squamous cell carcinomaCataractsPregnancyLactation
| Precautions | Risk of severe burns if sun exposure occurs within 24 hours of treatment, Increased risk of cataracts; protective eyewear required during UVA exposure and for 24 hours thereafter, Photosensitivity reactions may be severe; avoid concomitant photosensitizing drugs, Hepatotoxicity has been reported; monitor liver function tests, Avoid in patients with prior history of skin cancer or radiation therapy |
| Food/Dietary | Take with food or milk to minimize gastrointestinal irritation. Avoid alcohol, which may increase photosensitivity. Avoid foods high in psoralens (e.g., figs, limes, celery, parsnips, parsley) to reduce risk of phototoxic reactions. No significant food-drug interactions reported. |
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| L5 |
| Teratogenic Risk | Pregnancy category C. First trimester: potential teratogenic effects based on animal studies; avoid use. Second/third trimesters: insufficient human data; use only if benefit outweighs risk. Fetal risks include possible phototoxic reactions and potential for DNA damage. |
| Fetal Monitoring | Monitor liver function tests and renal function regularly. Observe for signs of phototoxicity and skin reactions. In pregnancy, consider fetal ultrasound to assess growth and anatomy if exposure occurs. |
| Fertility Effects | Animal studies have shown impaired fertility at high doses. Human data insufficient; may potentially affect spermatogenesis or oogenesis due to DNA intercalation. Use with caution in patients planning conception. |
| Clinical Pearls | Oxsoralen-Ultra (methoxsalen) is a psoralen used in PUVA therapy for psoriasis and vitiligo. Dose is based on body weight (0.4 mg/kg). Administer with milk or food to reduce GI upset. Monitor liver function and ANA at baseline. Protect eyes with UVA-blocking sunglasses for 24 hours post-dose. Avoid concurrent photosensitizing drugs (e.g., thiazides, tetracyclines). |
| Patient Advice | Take this medication with food or milk to prevent stomach upset. · Strictly avoid sun exposure for 24 hours after taking this medicine, even through glass or clouds. · Wear UVA-blocking sunglasses for 24 hours after each dose, both indoors and outdoors. · Do not use this medicine if you are allergic to psoralens or have a history of skin cancer. · Report any severe burning, blistering, or skin redness to your doctor immediately. · Women of childbearing age: use effective birth control during treatment; avoid pregnancy. · Men: use a condom during sexual activity for 24 hours after taking the dose. |