(1997; 132 pages) [French] [Spanish]
Ointment (crude coal tar), 1%
Coal tar is a keratolytic agent that inhibits excessive proliferation of epidermal cells by reducing DNA synthesis and mitotic activity to normal levels.
Coal tar is not significantly absorbed following topical application.
Treatment of chronic psoriasis, either alone or in combination with exposure to ultraviolet light.
Dosage and administration
Adults and children: 100 ml of solution should be thoroughly mixed with bath water and the patient should soak for 10-20 minutes. Treatment may be repeated daily until the lesions have resolved.
Alternatively, a thin layer of ointment is applied to the affected areas once daily until the lesions have resolved.
Phototherapy should not be started until at least 24 hours after treatment and until all traces of the coal tar preparation have been removed from the skin.
Known hypersensitivity to tar preparations.
Coal tar preparations should not be applied to inflamed, broken or infected skin.
Exposure to direct sunlight should be avoided as far as possible for at least 24 hours after treatment, because of the risk of photosensitivity reactions.
Although coal tar is a potential carcinogen, there is no evidence that it increases the risk of skin cancer at the doses used therapeutically.
Use in pregnancy
Safe use in pregnancy has not been demonstrated. Treatment should be deferred until after delivery whenever possible.
Coal tar preparations cause skin irritation. Rarely, allergic sensitization occurs.
Photosensitivity reactions may occur, particularly when other photosensitizing agents are used.
Patients should be warned that staining of the skin and hair may occur.
Preparations should be stored in tightly closed containers, protected from light. They should not be allowed to freeze.