Venous thrombosis during olanzapine treatment: a complex association.

Olanzapine, a second generation antipsychotic, has previously been associated with an increased risk of venous thromboembolism (VTE). In this mini-review we describe a case of a thirty-year-old schizophrenic patient who was diagnosed with a deep venous thrombosis (DVT) six months after starting olanzapine therapy, as well as seventeen other VTE cases in patients using olanzapine reported to the Netherlands Pharmacovigilance Centre Lareb. In 14 of these reports, patients had reported additional risk factors for VTE. We found disproportionate Reporting Odds Ratios (RORs) in the global database VigiBase for olanzapine and the reactions deep vein thrombosis (ROR of 1.38 with a 95% CI (Confidence Interval) of 1.22-1.57) and pulmonary embolism (ROR of 1.99 with a 95% CI of 1.81-2.19). The mechanism behind the association of olanzapine with VTE could be explained by two risk factors, substantial weight gain and lethargy, both common side effects of olanzapine. So far, a direct effect of olanzapine on platelet aggregation or coagulation has not been found. Schizophrenic patients are more likely to have diagnostic delay in the diagnosis of VTE, as symptoms such as lethargy and impaired pain perception result in diminished pain perception and pain expression, while they are at increased risk of developing VTE. Currently no validated risk score is available for detection of psychiatric patients who might benefit from pharmacologic VTE prophylaxis. In patients developing a VTE while being treated with olanzapine, discontinuation of olanzapine could be considered based on the individual risk profile, control of psychotic symptoms and antipsychotic treatment options.

Cholesterol embolisms as possible adverse drug reaction of direct oral anticoagulants.

The Netherlands Pharmacovigilance Centre Lareb has received two reports of cholesterol crystal embolisms associated with the use of a direct oral anticoagulant (DOAC). The European pharmacovigilance database contains several other cases concerning this association, and one report was published in the scientific literature. Cholesterol crystal embolisms were described in association with the use of several other antithrombotic drugs, although the role as an independent risk factor is not conclusive. The case series described in this article, indicates the possibility of an adverse drug reaction when a patient develops cholesterol crystal embolisms while using a DOAC.

Nephrotic syndrome under treatment with dasatinib: be aware of a possible adverse drug reaction.

The protein kinase inhibitor dasatinib, targeting BCR-ABL and Src family kinases, is used in chronic myeloid leukaemia and Philadelphia-chromosome positive acute lymphoblastic leukaemia. The Netherlands Pharmacovigilance Centre Lareb has received one report of nephrotic syndrome associated with the use of dasatinib. With some other protein kinase inhibitors, targeting vascular endothelial growth factor, nephrotic syndrome is a well-known adverse drug reaction. The Dutch and European pharmacovigilance databases and scientific literature contain several cases indicating a causal relationship between dasatinib and nephrotic syndrome. Nephrotic syndrome was recently added to the list of adverse drug reactions in the Dutch summary of product characteristics for dasatinib. It is important to recognise the possibility of this adverse drug reaction when a patient develops nephrotic syndrome under treatment with dasatinib.