This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Severe. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, a harmful effect on your heart may result.
What might happen:
You may experience an irregular heartbeat that may be life threatening.
What you should do about this interaction:
Contact your healthcare professionals (e.g. doctor or pharmacist) as soon as possible about taking these two medicines together or if you have taken mefloquine in the previous 15 weeks. They may already be aware of this drug interaction and may be monitoring you for it. If you have or have had an irregular heartbeat, your chances for experiencing this effect are increased. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Halfan (halofantrine) UK summary of product characteristics. Smith-Kline and French Laboratories, Inc. April, 1997.
2.Halfan (halofantrine hydrochloride) US prescribing information. SmithKline Beecham Pharmaceuticals October, 2001.
3.Lariam (mefloquine hydrochloride) US prescribing information. Roche Pharmaceuticals August, 2009.
4.Nosten F, ter Kuile FO, Luxemburger C, Woodrow C, Kyle DE, Chongsuphajaisiddhi T, White NJ. Cardiac effects of antimalarial treatment with halofantrine. Lancet 1993 Apr 24;341(8852):1054-6.