Elevated Clozapine Serum Level After Treatment With Amiodarone

Adverse effects of interactions between antipsychotics and medications used in the treatment of cardiovascular disorders

Background

High level of comorbidity between bipolar disorder or schizophrenia and cardiovascular diseases (CVD) in clinical practice may contribute to drug–drug interactions between medications used in these conditions. The aim of this study was to evaluate harmful interactions between antipsychotics and medications used in treatment of CVD.

Methods

The analysis of 52 cases of adverse reactions with a clinical picture indicates that they were the result of the combination of antipsychotic with cardiovascular medications.

Results

The highest number of interactions with antipsychotics was recorded among beta-blockers (n = 13, 25% of all cases), including cardiac arrhythmias [atrial fibrillation (n = 1): risperidone plus atenolol; bradycardia (n = 1): perphenazine with metoprolol; ventricular arrhythmias: sertindole with metoprolol (n = 1) and ziprasidone with sotalol (n = 3)] and hypotension [chlorprotixene with nebivolol or metoprolol (n = 2)]. 12 cases concerned statins—myalgia, myopathy, or creatine kinase elevation appeared after combination of atorvastatin with haloperidol (n = 1), quetiapine (n = 3) or risperidone (n = 1), and simvastatin with quetiapine (n = 5) or risperidone (n = 2). There were also cases of interactions observed for the use of antipsychotics with anti-arrhythmic drugs (amiodarone, flecainide, propafenone) (n = 11), calcium channel blockers (n = 6), and other cardiac medications: clonidine, dabigatran, doxazosin, ivabradine, and losartan (n = 10).

Conclusions

Due to a high risk of interactions and related adverse effects, particular attention should be paid while using cardiovascular medications with antipsychotics. Clinical decisions should be preceded by a detailed analysis of safety, risk–benefit ratio to search for, as safe as possible, drug combinations.