Consists of polytar, Zn pyrithione
Polytar (Fongitar Liquid) warnings
Pediatric Precautions
Safety and efficacy of coal tar preparations in children have not been established.
Carcinogenicity
Coal tar has been shown to be carcinogenic in humans following topical exposure. Chronic exposure to concentrated solutions of topical coal tar in industrial settings has been associated with skin cancer; however, the average period of exposure in these individuals was 20–24 years. The carcinogenic potential of coal tar was first described in chimney sweeps; scrotal cancer in chimney sweeps who started working at an early age and continued working through puberty was attributed to the soot and coal tar that lodged in their clothing. In a review of the literature for the possible occurrence of cancer in patients treated with coal tar, only 13 cases of skin cancer attributable to coal tar were reported during the period of 1900–1966; 2 of these patients also had been treated with arsenic. Most of these patients developed skin cancer in the anogenital region. Therefore, coal tar preparations should generally not be applied topically in the anogenital region. Data reported and included in the Third National Cancer Survey on patients using coal tar indicate that the incidence of skin cancer in patients treated with coal tar ointment is not increased compared with the expected incidence of skin cancer for the general population. It has been suggested that psoriasis may selectively protect against skin cancer.
It is generally accepted that coal tar contains carcinogenic substances. Biochemical studies indicate that coal tars used medically contain different carcinogens but in uneven concentrations. Carcinogens contained in coal tar are produced in the coking oven during the heating of coal because of the release of cancer-causing organic free radicals. The higher the temperature (1000°C and greater) in the coking oven, the greater and more varied is the production of free radicals. The smaller free radicals combine to produce polynuclear hydrocarbons, which are generally considered as the principal carcinogens in coal tar. At least 75 polynuclear hydrocarbons have been identified in coal tar. A number of animal studies have confirmed the carcinogenic potential of coal tar.
Although most experts recognize the concern regarding the carcinogenic potential of topically applied coal tar preparations, they generally believe that the contact time of a shampoo is of such short duration that this concern should not prevent the use of coal tar preparations on the scalp. However, the risk of cancer cannot be dismissed when coal tar preparations are used in the treatment of seborrheic dermatitis of the body and psoriasis, since the coal tar preparation is intended to remain in contact with the skin for prolonged periods and to be used chronically in these conditions. Although available information does not indicate an increased incidence of skin cancer in psoriatic patients treated with coal tar preparations, additional study is needed to determine the risk. The carcinogenic potential of combined therapy with coal tar preparations and UV radiation has not been fully determined. Although one study reportedly found an increased risk of skin cancer in patients with high exposure to coal tar preparations and UV radiation compared with those lacking high exposure, another study reportedly found that the incidence of skin cancer in patients receiving combined therapy with coal tar preparations and UV radiation was not appreciably increased compared with the expected incidence of skin cancer for the general population.
Pregnancy
Animal reproduction studies have not been performed with coal tar preparations. It is not known whether coal tar preparations can cause fetal harm when used topically by pregnant women. Coal tar preparations should be used during pregnancy only when clearly needed.
Lactation
It is not known whether topically applied coal tar is absorbed and/or distributed into milk. Because of the potential for serious adverse reactions (i.e., carcinogenicity) from coal tar preparations in nursing infants, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.
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Information checked by Dr. Sachin Kumar, MD Pharmacology
