Risk of venous thromboembolism due to antipsychotic drug therapy

Abstract

An increasing number of reports suggest a link between venous thromboembolism (VTE) and the use of antipsychotics. To better understand this association the available body of evidence has been critically scrutinised. Relevant articles were identified in the databases Scopus and PubMed. Several observational studies using different methodologies show an increased risk of VTE in psychiatric patients. This elevated risk seems to be related to the use of antipsychotic medication and in particular to the use of clozapine and low-potency firstgeneration drugs. Many studies investigating the association have, however, methodological limitations. The biological mechanisms involved in the pathogenesis of this possible adverse reaction are largely unknown but several hypotheses have been suggested such as druginduced sedation, obesity, increased levels of antiphospholipid antibodies, enhanced platelet aggregation, hyperhomocysteinemia and hyperprolactinemia. The association may also be related to underlying risk factors present in psychotic patients. Physicians need to be aware of this possible adverse drug reaction. Although supporting evidence has not been published they should consider discontinuing or switching the antipsychotic treatment in patients experiencing VTE. In addition, although data is lacking, the threshold for considering prophylactic antithrombotic treatment should be low when risk situations for VTE arise, such as immobilisation, surgery and so on.

Antipsychotic Drug Use and the Risk of Venous Thromboembolism in Elderly Patients

“…Since 1953, sporadic case reports and case series have suggested that conventional APD use is an independent risk factor for VTE. 5 In a nested case-control study, Zornberg and Jick 6 demonstrated that current exposure to conventional APDs significantly increases the risk of idiopathic VTE (odds ratio [OR], 7.1; confidence interval [CI], 2.3Y21.9). Kamijo et al 7 studied 16 patients with idiopathic acute pulmonary thromboembolism (mean age, 56), of whom 6 (44%) used conventional antipsychotic drugs; and 1 patient, risperidone.…”

Anticoagulation and Psychotropic Medications

“…In addition, patients who are on antipsychotic medications are at an increased risk of venous thromboembolism [31]; the relationship has been highlighted mostly with clozapine and low-potency first-generation antipsychotics [31].…”

An unusual complication of a long-acting injectable antipsychotic: deep venous thrombosis caused by olanzapine pamoate

“…In several studies, psychiatric disorders and the medications used for them are also accused of the development of DVT. The increased risk of DVT in patients who are treated with antipsychotic drugs has been reported in several cases [8]. Clozapine is noticeably the most mentioned drug with thromboembolic complications, but olanzapine is also subject to many reports [9].…”