Drug Interaction Report

MONITOR: Amisulpride can cause dose- and concentration-dependent prolongation of the QT interval. The concomitant use of amisulpride with agents that can cause bradycardia may theoretically potentiate the risk of QT interval prolongation and torsade de pointes arrhythmia. In 40 healthy Caucasian and Japanese subjects, the maximum mean difference in QTcF (Fridericia corrected QT interval) from placebo after baseline correction was 5.0 ms following a 5 mg IV infusion over 2 minutes and 23.4 ms following a 40 mg IV infusion over 8 minutes. A maximum mean difference of 13.4 ms is predicted for a 10 mg IV infusion over 1 minute based on the exposure-QTcF response relationship identified from the data in the study. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: Caution and clinical monitoring (e.g., electrocardiogram, serum electrolytes) are recommended if amisulpride is used in combination with other drugs that can cause bradycardia. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

MONITOR: Many psychotherapeutic and CNS-active agents (e.g., anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, alcohol, muscle relaxants) exhibit hypotensive effects, especially during initiation of therapy and dose escalation. Coadministration with antihypertensives and other hypotensive agents, in particular vasodilators and alpha-blockers, may result in additive effects on blood pressure and orthostasis.

MANAGEMENT: Caution and close monitoring for development of hypotension is advised during coadministration of these agents. Some authorities recommend avoiding alcohol in patients receiving vasodilating antihypertensive drugs. Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients should also avoid driving or operating hazardous machinery until they know how the medications affect them.