A case of carbamazepine-induced thrombocytopenia is reported. The pati
ent, a 38-year-old female, developed thrombocytopenia 10 days after re
ceiving 400 mg carbamazepine daily. The presence of an anti-IgG carbam
azepine-dependent platelet-reactive antibody was documented. Using flo
w cytometry, the drug-induced antibody.was detected at a drug concentr
ation as low as 10(-6) M.