JAMA. 1975 Jan; 231(4): 352-5.

Agranulocytosis caused by Chinese herbal medicines. Dangers of medications containing aminopyrine and phenylbutazone.

Ries CA, Sahud MA.

Four non-Chinese patients, middle-aged or older, developed agranuloctyosis while taking Chinese herbal medicines for relief of arthritis and back pain. All four developed life-threatening infections with bacterial sepsis; one died. The herbal medicines were shown to contain substantial amounts of undeclared aminopyrine and phenylbutazone, drugs that are well-known causes of agranulocytosis. These Chinese herbal medicines are widely available over the counter throughout the United States.