Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Mefloquine is a myocardial depressant and can cause ECG abnormalities. Theoretically, coadministration with other agents that can affect cardiac conduction (e.g., antiarrhythmic agents, beta blockers, calcium channel blockers, certain antihistamines, tricyclic antidepressants, phenothiazines, some neuroleptics) may result in additive effects and increased risk of ventricular arrhythmias including ventricular tachycardia and torsade de pointes. Parenteral studies in animals have shown that mefloquine possesses 20% of the antifibrillatory action of quinidine and can cause 50% of the increase in PR interval reported with quinine. ECG alterations reported with mefloquine include sinus bradycardia, sinus arrhythmia, first degree AV block, prolongation of the QTc interval, and abnormal T waves. According to mefloquine labeling, there has been one report of cardiopulmonary arrest, with full recovery, in a patient who was taking a beta blocker (propranolol).

MANAGEMENT: Caution and clinical monitoring are recommended if mefloquine is used in combination with other drugs that can prolong the QT interval or otherwise affect cardiac conduction. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes or other arrhythmia such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

Food can enhance the levels of mefloquine in your body. Take mefloquine immediately after a meal. This will make it easier for your body to absorb the medication. Take each dose with a full glass, at least 8 ounces (240 mL) of water. For children or those who have difficulty swallowing, mefloquine can be crushed and mixed with water or sugar water. Talk to your healthcare provider if swallowing the tablets is difficult.