Aim: Immun thrombocytopenic purpura (ITP) is a disease characterized by early destruction of platelets by antibodies attached onto platelet surface. Mechanisms responsible for this destruction have not been clarified yet. But some infectious agents, some drugs, and their metabolites are claimed to be responsible.

Case: Twenty-four years old female was diagnosed as ITP and was successfully treated by oral steroid. After 16 months she was admitted to hospital because she had fatigue and her platelet count was 16x10⁹/L. It was learned that she used lithium for manic-depressive episode. Following the withdrawal of the drug her plateler count recovered.

Conclusion: It is well known that some drugs and their metabolites are responsible for ITP. Use of such drugs or any other drug should be used carefully, and in the case of any suspicion their use should be limited or prohibited in ITP patients.