Lumefantrine

Lumefantrine (= benflumetol) was registered in China in 1987 for the treatment of P. falciparum malaria. It is an arylamine alcohol which was synthesised at the Chinese Institute of Military Medical Sciences. The half-life in the blood is approximately 4 days. The product is not active on the liver stages or gametocytes. Lumefantrine, like chloroquine, probably destroys haem polymerisation (a detoxifying pathway for the parasite). It is synergistic with artemether. The combination artemether-lumefantrine is used at a ratio of 1:6. Each tablet contains 20 mg artemether and 120 mg lumefantrine. This combination is also known as co-artemether (Riamet®, Co-Artem®). This combined product has been available since 1999 in Switzerland and in various African countries. There is as yet no paediatric syrup or injectable form. The recommended dose for an adult is 4 tablets once per day for 4 days (semi-immune person). For an adult with little or no immunity to malaria the advice is to take 4 tablets at the time of diagnosis, 4 tablets 8 hours later, 4 tablets 24 hours later and 4 tablets 48 hours later (i.e. 4 x 4 tablets).

Lumefantrine is a lipophilic molecule with very low toxicity. It is a yellow powder which is only partially soluble in water. Absorption in the intestine is highly variable from person to person and is greatly increased (up to 16-fold) by fatty food (similar to halofantrine). Since people who are ill generally do not eat much, this has important consequences. Early in the treatment very little lumefantrine is absorbed. In combinations such as co-artemether, the artemether is responsible for the initial important reduction in the number of parasites and the low residual numbers of parasites is then cleared up by lumefantrine.

Category: Medicine Notes