Modern chemistry has not been entirely kind to man. With accumulating experience, it becomes more and more evident that some of our most widely used and apparently innocuous drugs have toxic properties. Even the analgesics aspirin and phenacetin, found in everyone's medicine cabinet, have been implicated in producing serious disease states.The most frequently implicated component of analgesic mixtures has been phenacetin. Its most obvious toxic effect, and therefore the first to be discovered, is cyanosis, which may follow ingestion of over 1 g of phenacetin daily for months. The cyanosis is a consequence of the accumulation of nonfunctioning sulf-hemoglobin