benzofurans and Erythema

Amiodarone-induced cutaneous photosensitivity was studied in 12 subjects treated with the drug. The action spectrum for the abnormal response to sunlight was shown to be within the range of 335-460 (+/- 30) nm. The clinical features of the photosensitivity response suggested that it was most probably a phototoxic reaction, a conclusion supported by the results of in vitro studies which indicated activity mainly against cell membranes. Of the five in vitro models used, three--namely photohaemolysis, the inhibition of DNA synthesis in PHA stimulated lymphocytes and the killing of mouse peritoneal macrophages--provided unequivocal evidence of the phototoxic potential of both amiodarone and its major metabolite, desethylamiodarone. In each model desethylamiodarone produced a greater effect by a factor of between 2 and 10. In vitro, UV-B wavelengths produced a greater effect than UVA but the difference between the effective wavelengths in vivo and in vitro might be explained by the greater absorption of the shorter wavelength UV-B in the epidermis. Zinc oxide-containing preparations appeared to be the most effective in reducing the cutaneous photosensitivity. It is suggested that the long-term cutaneous pigmentation resulting from oral amiodarone has a significant photosensitivity component.

Topics: Adult; Aged; Amiodarone; Benzofurans; Cells, Cultured; Child; Erythema; Erythrocytes; Female; Humans; Lymphocytes; Macrophages; Male; Middle Aged; Photosensitivity Disorders; Radiation Dosage; Sunscreening Agents

Amiodarone hydrochloride is currently being investigated in the United States as a cardiac antiarrhythmic agent. Previous reports from Europe indicate that amiodarone occasionally causes a cutaneous photosensitivity reaction that may be associated with a peculiar blue-gray discoloration of the skin. In addition, corneal microdeposits of yellow-brown granules may occur. We report observations on a case of amiodarone photosensitivity and corneal deposits developing in a patient shortly after amiodarone therapy was begun. Symptoms included burning and stinging of the skin, with redness and swelling that developed immediately after sun exposure. Phototesting showed that the photoactivating wavelengths were primarily in the long-wave UV-A spectrum between 350 and 380 nm. Prior application of a 10% dioxybenzone sunscreen greatly reduced the phototest reaction. Four weeks after the patient stopped taking amiodarone, the UV-A sensitivity was still present but diminished, and by ten weeks it had disappeared. During this time, the corneal deposits were reduced in number. All ten patients we have treated so far with amiodarone for cardiac arrhythmias have shown a similar photosensitivity, indicating that this is probably a phototoxic reaction.

Topics: Aged; Amiodarone; Arrhythmias, Cardiac; Benzofurans; Erythema; Humans; Male; Photosensitivity Disorders; Skin; Time Factors; Ultraviolet Rays

Topics: Adolescent; Ampicillin; Benzofurans; Drug Eruptions; Erythema; Humans; Infectious Mononucleosis; Male

The antiinflammatory activity of R-803 (alpha-methyl-3-phenyl-7-benzofuranacetic acid), a new nonsteroidal drug, has been demonstrated. The oral administration of R-803 inhibits carrageenan-induced edema of the rat's paw, ultraviolet-induced erythema of guinea-pig skin, adjuvant-induced and 6-sulfonamidoindazole-induced arthritides of the rat at doses in the range of 1.0 to 6.0 mg/kg. It also inhibits the cotton pellet-induced granuloma in the rat at higher doses.

Topics: Animals; Anti-Inflammatory Agents; Arthritis; Benzofurans; Edema; Erythema; Female; Granuloma; Guinea Pigs; Male; Radiation Injuries, Experimental; Rats; Ultraviolet Rays