Quinine-induced severe thrombocytopenia: the importance of taking a detailed drug history.

Drugs can lead to severe life-threatening thrombocytopenia. The mechanisms of drug-induced thrombocytopenia are increased destruction by immune-mediated platelet destruction or decreased platelet production by bone marrow suppression. Quinine is a drug used for the treatment of malaria and nocturnal leg cramps and is also an important ingredient in some herbal preparations. Quinine can very rarely cause thrombocytopenia by immune-mediated platelet destruction. In a patient with thrombocytopenia, a detailed history of all the medications including over-the-counter medications and herbal preparations is very important.