Effect of psychotropics on bleeding and clotting factors

Introduction: Coagulopathies are rare side effects with psychotropics and are thus frequently overlooked while prescribing. Selective serotonin reuptake inhibitors are more commonly associated with deranged bleeding parameters, the most frequent being decreased platelet aggregability and activity, and the prolongation of bleeding time. Thrombocytopenia as a side effect of valproate administration often goes unnoticed, and olanzapine has been associated with a higher risk of venous thromboembolism. The aim of our study was to determine what percentage of patients on psychotropics develop changes in bleeding parameters, and whether these changes are significant enough to warrant routine monitoring of these parameters. Material and methods: This was a prospective observational, single-center study which included 100 patients newly started on psychotropics. Those on medications affecting bleeding parameters or having an acute illness like sepsis were excluded. Patients were only on a single psychotropic agent, and their bleeding parameters — prothrombin time, international normalized ratio (INR), bleeding time, clotting time (CT) and platelet count — were assessed at baseline and after 15 and 30 days. Results: Mean values of prothrombin time (PT), INR, bleeding time and CT increased over time while the mean value of platelet count showed a decreasing trend but no clinical manifestations were noted. Olanzapine was the only drug causing a reduction of PT, INR and CT and valproate was the only drug affecting platelet count. Paroxetine affected the bleeding parameters the most among the antidepressants. Sertraline, fluoxetine, amitriptyline and haloperidol were the other drugs affecting various bleeding parameters, though the effects were less compared to the other drugs in the study. Conclusions: Routine monitoring of bleeding parameters in patients receiving psychotropics is not warranted, but caution must be taken while prescribing these drugs, especially in groups such as patients with known blood dyscrasias or peri-operative patients