8-MOP Side Effects

Generic name: methoxsalen

Medically reviewed by Drugs.com. Last updated on Dec 3, 2024.

Note: This document provides detailed information about 8-MOP Side Effects associated with methoxsalen. Some dosage forms listed on this page may not apply specifically to the brand name 8-MOP.

Applies to methoxsalen: oral capsule liquid filled.

Other dosage forms:

• injection solution

Precautions

Your doctor should check your progress at regular visits to make sure this medicine is working and that it does not cause unwanted effects. Eye examinations should be included.

This medicine increases the sensitivity of your skin and lips to sunlight. Therefore, exposure to the sun, even through window glass or on a cloudy day, could cause a serious burn. If you must go out during the daylight hours:

• Before each treatment, cover your skin for at least 24 hours by wearing protective clothing, such as long-sleeved shirts, full-length slacks, wide-brimmed hat, and gloves. In addition, protect your lips with a special sun block lipstick that has a skin protection factor (SPF) of at least 15. Check with your doctor before using sun block products on other parts of your body before a treatment, since sun block products should not be used on the areas of your skin that are to be treated.
• After each treatment, cover your skin for at least 8 hours by wearing protective clothing. In addition, use a sun block product that has a skin protection factor (SPF) of at least 15 on your lips and on those areas of your body that cannot be covered.

If you have any questions about this, check with your health care professional.

Your skin may continue to be sensitive to sunlight for some time after treatment with this medicine. Use extra caution for at least 48 hours following each treatment if you plan to spend any time in the sun. In addition, do not sunbathe anytime during your course of treatment with methoxsalen (the active ingredient contained in 8-MOP)

For 24 hours after you take each dose of methoxsalen, your eyes should be protected during daylight hours with special wraparound sunglasses that totally block or absorb ultraviolet light (ordinary sunglasses are not adequate). This is to prevent cataracts. Your doctor will tell you what kind of sunglasses to use. These glasses should be worn even in indirect light, such as light coming through window glass or on a cloudy day.

This medicine may cause your skin to become dry or itchy. However, check with your doctor before applying anything to your skin to treat this problem.

Common side effects of 8-MOP

Some side effects of methoxsalen may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Treatment with this medicine usually causes a slight reddening of your skin 24 to 48 hours after the treatment. This is an expected effect and is no cause for concern. However, check with your doctor right away if your skin becomes sore and red or blistered.

There is an increased risk of developing skin cancer after use of methoxsalen. You should check your body regularly and show your doctor any skin sores that do not heal, new skin growths, and skin growths that have changed in the way they look or feel.

Premature aging of the skin may occur as a result of prolonged methoxsalen therapy. This effect is permanent and is similar to what happens when a person sunbathes for long periods of time.

Serious side effects of 8-MOP

Along with its needed effects, methoxsalen may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking methoxsalen:

• Blistering and peeling of skin
• reddened, sore skin
• swelling (especially of feet or lower legs)

For healthcare professionals

Applies to methoxsalen: compounding powder, injectable solution, oral capsule.

General adverse events

The most common adverse event was nausea, which may be minimized or avoided by taking the medication with milk or food, or dividing the dose into 2 portions taken approximately 30 minutes apart.^[Ref]

Dermatologic

• Very common (10% or more): Pruritus (10%)
• Frequency not reported: Erythema, hypopigmentation, vesiculation and bullae formation, non-specific rash, herpes simplex, miliaria, urticaria, folliculitis, cutaneous tenderness, extension of psoriasis
• Postmarketing reports: Rash^[Ref]

Erythema:

Mild, transient erythema at 24 to 48 hours after PUVA therapy is expected and indicates a therapeutic reaction.

Any area showing moderate (grade 2 or higher) erythema should be shielded during subsequent UVA exposure until the erythema has resolved.

Grade 2 or higher erythema that appears within 24 hours after treatment may signal a potentially severe burn.

Erythema may progressively worsen over the next 24 hours, since peak erythemal reaction characteristically occurs 48 hours or later after methoxsalen ingestion.

Monitor the patient closely and protect from further UVA and sunlight exposures.

Differences between PUVA erythema and sunburn or UVB phototherapy:

The percent transmission through skin of UVS varies from 0 to 34%, where UVA varies from 1 to 80% (UVA is transmitted through a larger percentage of the skin)

PUVA induced DNA lesions may lead to a DNA crosslink, which is more lethal and psoralen-DNA photoproducts may be unfamiliar substrates for DNA repair enzymes.

DNA synthesis is suppressed longer after PUVA.

The time course of delayed erythema with PUVA is different and may not involve the usual mediators seen in sunburn; PUVA-induced redness may be just beginning at 24 hours (UVB erythema is past its peak by this time).

Histological alterations from PUVA show more dermal vessel damage and longer duration of epidermal and dermal abnormalities.^[Ref]

Pruritus can often be alleviated by frequent application of bland emollients or other topical agents.

Severe pruritus may require systemic treatment. If pruritus is unresponsive to these measures, shield pruritic areas from further UVA exposure until it resolves.

Discontinue treatment until pruritus resolution for intractable generalized pruritus.

Cardiovascular

• Common (1% to 10%): Hypotension
• Frequency not reported: Arrhythmia^[Ref]

Gastrointestinal

• Very common (10% or more): Nausea (10%)
• Common (1% to 10%): Vomiting
• Frequency not reported: Gastrointestinal disturbances
• Postmarketing reports: Dysgeusia^[Ref]

Immunologic

• Common (1% to 10%): Infection/catheter related infection/ sepsis
• Frequency not reported: Folliculitis^[Ref]

Psychiatric

• Frequency not reported: Nervousness, insomnia, depression^[Ref]

Hypersensitivity

• Postmarketing reports: Allergic reaction^[Ref]

Local

• Common (1% to 10%): Vascular access complication^[Ref]

Other

• Common (1% to 10%): Transient fever
• Frequency not reported: Edema, malaise
• Postmarketing reports: Pyrexia^[Ref]

Nervous system

• Frequency not reported: Dizziness, headache^[Ref]

Musculoskeletal

• Frequency not reported: Leg cramps^[Ref]

See also:

Further information

8-MOP side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer