Venous thromboembolism during treatment with antipsychotics: Results of a drug surveillance programme

Objectives: Venous thromboembolism (VTE) can be a life-threatening medical condition that may lead to leg swelling, respiratory distress and death.

Methods: The AMSP (Arzneimittelsicherheit in der Psychiatrie) is a continuous multicentre drug surveillance programme that assesses severe adverse drug reactions during treatment of psychiatric inpatients. We report on a total of 264,422 inpatients who were treated with antipsychotics (APs) and monitored from 1993 to 2011 in 99 psychiatric hospitals.

Results: During this period VTE events were reported for 89 inpatients, corresponding to an occurrence rate of 34 cases per 100,000 inpatient admissions treated with APs or 43 cases per 10,000 person-years. The occurrence of VTE was greatest in patients over the age of 65 years of age with mood disorders. The chemical class of butyrophenones (48/100,000) followed by atypical APs (36/100,000) showed the highest occurrence rate for VTE compared to thioxanthenes (23/100,000), which were less associated with VTE. If imputed alone, pipamperone (61/100,000) and risperidone (55/100,000) were most frequently associated with VTE. In general, there was no difference in occurrence rate of VTE between high- and low-potency APs.

Conclusions: These results suggest that clinicians should consider AP drug exposure as a potential risk factor for VTE for patients older than 65 years. Additionally, the diagnosis of an affective disorder seems to increase the risk for VTE.