Platexan Special Precautions

Diminished Antiplatelet Activity in Patients with Impaired CYP2C19 Function: Clopidogrel is a prodrug. Inhibition of platelet aggregation by clopidogrel is achieved through an active metabolite. The metabolism of clopidogrel to its active metabolite can be impaired by genetic variations in CYP2C19.
The metabolism of clopidogrel can also be impaired by drugs that inhibit CYP2C19, such as omeprazole or esomeprazole. Avoid concomitant use of Clopidogrel bisulfate with omeprazole or esomeprazole because both significantly reduce the antiplatelet activity of Clopidogrel bisulfate.
General Risk of Bleeding: Thienopyridines, including Clopidogrel bisulfate, increase the risk of bleeding.
Thienopyridines inhibit platelet aggregation for the lifetime of the platelet (7-10 days). Because the half-life of clopidogrel's active metabolite is short, it may be possible to restore hemostasis by administering exogenous platelets; however, platelet transfusions within 4 hours of the loading dose or 2 hours of the maintenance dose may be less effective.
Discontinuation of Clopidogrel bisulfate: Discontinuation of Clopidogrel bisulfate increases the risk of cardiovascular events. If Clopidogrel bisulfate must be temporarily discontinued (e.g., to treat bleeding or for surgery with a major risk of bleeding), restart it as soon as possible. When possible, interrupt therapy with Clopidogrel bisulfate for five days prior to such surgery. Resume Clopidogrel bisulfate as soon as hemostasis is achieved.
Thrombotic Thrombocytopenic Purpura (TTP): TTP, sometimes fatal, has been reported following use of Clopidogrel bisulfate, sometimes after a short exposure (<2 weeks). TTP is a serious condition that requires urgent treatment including plasmapheresis (plasma exchange). It is characterized by thrombocytopenia, microangiopathic hemolytic anemia (schistocytes [fragmented RBCs] seen on peripheral smear), neurological findings, renal dysfunction, and fever.
Cross-Reactivity among Thienopyridines: Hypersensitivity including rash, angioedema or hematologic reaction have been reported in patients receiving Clopidogrel bisulfate, including patients with a history of hypersensitivity or hematologic reaction to other thienopyridines.
Renal Impairment: Experience is limited in patients with severe and moderate renal impairment.
Hepatic Impairment: No dosage adjustment is necessary in patients with hepatic impairment.
Use in Children: Safety and effectiveness in pediatric populations have not been established.
Use in the Elderly: No dosage adjustment is necessary in elderly patients.