To the Editor.—
Although azaribine has been shown to be an effective drug in the treatment of psoriasis, the Food and Drug Administration has recently prohibited the use of this antimetabolite because of the possibility of an associated increased incidence of thromboembolism. We present a hypothesis and some preliminary supporting data that may explain this adverse effect.In 1969, high dosages of azaribine (400 mg/kg/day) were shown to result in the urinary excretion of various amino acids, including homocystine.1, 2 Until recently, this appeared to be a mere biochemical curiosity. However, with the report of vascular complications in patients who were on a regimen of azaribine, similar to those complications found in patients with hereditary homocystinuria, we screened our patients who were receiving azaribine for the presence of homocystine in the blood and the urine. As homocystine is normally not present in either the blood or the urine, detectable
Shupack JL, Grieco AJ, Epstein AM, Sansaricq C, Snyderman SE. Azaribine, Homocystinemia, and Thrombosis. Arch Dermatol. 1977;113(9):1301–1302. doi:10.1001/archderm.1977.01640090149047
Monkeypox Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.