Drug General Information (ID: DDICIDZL53)
Drug Name			Mefloquine		Drug Info		Halofantrine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antimalarial Agents				Antimalarial Agents
Structure

Mechanism of Mefloquine-Halofantrine Interaction (Severity Level: Major)
Increased risk of prolong QT interval Click to Show/Hide Mechanism Graph
Drug Name		Mefloquine				Halofantrine
Mechanism		Prolong QT interval				Prolong QT interval
Key Mechanism Factor 1
		Factor Name		QT interval
		Factor Description		Long QT syndrome is a heart signaling disorder that can cause a fast, chaotic heartbeat (arrhythmia). Many people may not exhibit symptoms, and usually the condition is detected during routine medical tests. In others, the most common symptoms include: sudden fainting, palpitations, dizziness, seizures, sudden death.
Mechanism Description		Increased risk of prolong QT interval by the combination of Mefloquine and Halofantrine

Recommended Action
Management		Halofantrine should not be administered with mefloquine or within 15 weeks of the last dose of mefloquine due to increased risk of potentially fatal prolongation of the QTc interval. The manufacturer recommends performing an ECG before initiating halofantrine therapy and monitoring cardiac rhythm during and for 8 to 12 hours after completion of therapy.

References
1	Abernethy DR, Wesche DL, Barbey JT, et al. "Stereoselective halofantrine disposition and effect: concentration-related QTc prolongation." Br J Clin Pharmacol 51 (2001): 231-7. [PMID: 11298069]
2	Darpo B "Spectrum of drugs prolonging QT interval and the incidence of torsades de pointes." Eur Heart J Suppl 3(Suppl K) (2001): K70-80.
3	Nosten F, ter Kuile FO, Luxemburger C, et al "Cardiac effects of antimalarial treatment with halofantrine." Lancet 341 (1993): 1054-6. [PMID: 8096959]
4	Product Information. Halfan (halofantrine). GlaxoSmithKline, Philadelphia, PA.
5	Product Information. Lariam (mefloquine). Roche Laboratories, Nutley, NJ.
6	Sudden death in a traveler following halofantrine administration--Togo, 2000. MMWR Morb Mortal Wkly Rep 50 (2001): 169-70, 179. [PMID: 11393488]