COMPOSITION :
OCTAMOP LOTION
Methoxsalen USP 0.75%w/v
(Ammoidine)
Non Aqueous base q.s.
Molecular formula
OCTAMOP LOTION C12H8O4
CLINICAL PHARMACOLOGY :
The combination treatment regimen of psoralen (P) and ultra- violet radiation of 320-400 nm wavelength commonly referred to as UVA is known by the acronym, PUVA. Skin reactivity to UVA (320-400nm) radiation is markedly enhanced by the topical application of methoxsalen lotion (OCTAMOP LOTION ).
OCTAMOP LOTION in vitiligo (mechanism of action):
OCTAMOP LOTION acts as a photosensitizer. Topical application of OCTAMOP LOTION and subsequent exposure to UVA, whether artificial or sunlight, can cause cell injury. If sufficient cell injury occurs in the skin an inflammatory reaction will result. The most obvious manifestation of this reaction is delayed erythema, which may not begin for several hours and may not peak for 2 to 3 days or longer. The length of time the skin remains sensitized or when the maximum erythema will occur is quite variable from person to person. The erythematous reaction is followed over several days or weeks by repair which is manifested by increased melanization of the epidermis and thickening of the stratum comeum. The exact mechanics are unknown but it has been suggested melanocytes in the hair follicles are stimulated to move up the follicle and to repopulate the epidermis.
INDICATIONS AND USAGE :
OCTAMOP LOTION is indicated for repigmentation of vitiligo in conjunction with controlled doses of UVA (320-400nm) or sunlight. OCTAMOP LOTION can be used either alone, or along with oral therapy with Octamop tablets. OCTAMOP LOTION can be used for children 2 years old and older who have localized patches of vitiligo. OCTAMOP LOTION is used for vitiligo patients with serious renal or hepatic diseases, diabetes, blood dyscrasias, or if oral methoxsalen treatment has not been well tolerated.
DOSAGE AND ADMINISTRATION :
Dilution :
If physician has advised dilution, to follow his advice. As a general guideline, it is advisable to use a weaker solution of OCTAMOP LOTION by diluting upto 1:10 with Eau De Cologne (i.e.1 part of OCTAMOP LOTION to be mixed with 10 parts of Eau De Cologne) for the first 15 days of treatment. As the medicine starts working and the patient’s tolerance power increases, the treating physician can increase the proportion of the active medication.
Method of application :
1. Before applying, wash the patches with soap and water.
2 Apply the correct dilution of OCTAMOP LOTION , as advised by doctor, with the brush provided. Rubbing is not necessary. Wash the finger afterwards to avoid photosensitization and possible burns.
3. One hour after application, expose the areas to sunlight/UVA.
4. After sunlight/UVA exposure, wash off OCTAMOP LOTION from the patches, and cover all the treated vitiligo patches to protect from further ultra-violet radiation.
Sunlight Exposure – Time & Method :
The schedule of exposure to be followed very accurately is as follows:
- Half a minute per day for the first week.
- One minute per day for the second week.
- Two minute per day for the third week.
After every exposure, the patient should cover all the treated vitiligo patches. This protective measure is essential as most of the local reactions are due to inadvertent exposure and additional solar radiation. The proper time for solar exposure is between 11:30 a.m. to 1:30 p.m.
What to expect?
This exposure provokes a slight erythema (irritation blister). The exposure could be increased in duration according to the patient’s tolerance. Within a few months, the threshold of erythema (irritation blister) can be reached, in 5 to 6 minutes. Once the patch becomes red, the duration of exposure should not be increased beyond 15 minutes.
CONTRAINDICATIONS :
1.Patients exhibiting idiosyncratic reactions to psoralen compounds or a history of sensitivity reactions to them.
2. Patients exhibiting melanoma or with a history of melanoma.
3. Patients exhibiting invasive skin carcinoma generally.
4. Patients with photosensitivity diseases such as porphyria, acute lupus erythematosus, xeroderma pigmentosum, etc. Children less than 2 years.
WARNINGS :
A.Skin burns: Serious skin burns from either UVA or sunlight (even through window glass) can result if recommended exposure schedule is exceeded and / or protective covering or sunscreens are not used.
B. Carcinogenecity: No reports of skin cancer in human studies, as a complication for topical treatment for vitiligo. However, it is recommended that caution be exercised when the patient is fair-skinned or has a history of prior coal tar UVA treatment, or has had ionizing radiation or taken arsenical compounds. Such patients who subsequently have oral psoralen-UVA treatment (PUVA) are at increased risk for developing skin cancer.
3.Concomitant therapy: Special care should be exercised in treating patients who are receiving concomitant therapy (either topically or systemically) with known photosensitizing agents such as anthralin, coal tar, or coal tar derivatives, griseofulvin, phenothiazines, nalidixic acid, halogenated salicylanilides (bacteriostatic soaps), sulfonamides, tetracyclines, thiazides and certain organic staining dyes such as methylene blue, toluidine blue, rose bengal, and methyl orange.
PRECAUTIONS :
1. This product should be applied only in small well-defined lesions and preferably on lesions, which can protected by clothing or a sunscreen from subsequent exposure to radiant UVA.
2. Pregnancy: Topical methoxsalen should be used in pregnant women only where clearly indicated.
3. Nursing mother: It is not known whether topical methoxsalen is absorbed or excreted in human milk. Caution is advised when topical methoxsalen is used in a nursing mother.
ADVERSE REACTIONS :
Systemic side effects have not been reported. The most common adverse reaction is severe burns of the treated area from overexposure to UVA, including sunlight. In case of an inflammatory reaction, the application of the product should be interrupted. The inflammation can be treated in the same way as an ordinary burn of the first degree.
STORAGE INSTRUCTIONS :
Protect from light. Store in a cool, dry, dark place.
