Possible association between the Norplant contraceptive system and thrombotic thrombocytopenic purpura.

Background: Thrombotic thrombocytopenic purpura (TTP) is a rare, potentially fatal disease of uncertain etiology. Early diagnosis and treatment are essential to patient survival. The ]purpose of this report is to describe three patients with levonorgestrel implants (Norplant system) who developed TTP.

Cases: A 24-year-old woman with levonorgestrel implants in place for 7 months was admitted to our hospital for treatment of TTP. Clinical symptoms included easy bruising, menorrhagia, headaches, and fever; laboratory evaluation revealed thrombocytopenia (18 x 10(9)/L) and microangiopathic hemolytic anemia. She was treated with plasmapheresis, and the implants were removed. Through the Freedom of Information Act, we reviewed all adverse events associated with Norplant use reported to the Food and Drug Administration (FDA) as of the end of 1992. Two additional cases were identified.

Conclusions: Although a causal relationship between progestogen-only contraceptives and TTP is not established by the data presented, these three cases may represent an increased incidence of TTP in women using levonorgestrel implants. Patients who receive Norplant should be advised to seek medical attention if symptoms appear. Physicians and other health care providers should be aware of the possible association between use of the Norplant system and TTP and are urged to report similar cases to the FDA.