Artemether causes relatively few side effects.[4] An
irregular heartbeat may rarely occur.[4] While there is evidence that use during
pregnancy may be harmful in animals, there is no evidence of concern in humans.[4] The
World Health Organization (WHO) therefore recommends its use during pregnancy.[4] It is in the
artemisinin class of medication.[4]
Artemether is an antimalarial drug for uncomplicated malaria caused by P. falciparum (and chloroquine-resistant P. falciparum) or chloroquine-resistant P. vivax parasites.[1][7] Artemether can also be used to treat severe malaria.[2]
Artemether can also be used in treating and preventing trematode infections of
schistosomiasis when used in combination with
praziquantel.[10]
Artemether is rated category C by the FDA based on animal studies where artemisinin derivatives have shown an association with fetal loss and deformity. Some studies, however, do not show evidence of harm.[11][12]
Side effects
Possible side effects include cardiac effects such as bradycardia and
QT interval prolongation.[1][13] Also, possible central nervous system toxicity has been shown in animal studies.[14][15]
Drug interactions
Plasma artemether level was found to be lower when the combination product was used with lopinavir/ritonavir.[15] There is also decreased drug exposure associated with concurrent use with efavirenz or nevirapine.[16][17]
Artemether/lumefantrine should not be used with drugs that inhibit
CYP3A4.[1][18]
Hormonal contraceptives may not be as efficacious when used with artemether/lumefantrine.[18]
Pharmacology
Mechanism of action
A possible mechanism of action is that artemisinin drugs exert their cidal action by inhibiting
PfATP6. Since PfATP6 is an enzyme regulating cellular calcium concentration, its malfunctioning will lead to intracellular calcium accumulation, which in turns causes cell death.[19]
Pharmacokinetics
Absorption of artemether is improved 2- to 3-fold with food. It is highly bound to protein (95.4%). Peak concentrations of artemether are seen 2 hours after administration.[3]
Artemether is metabolized in the human body to the active metabolite, dihydroartemisinin, primarily by hepatic enzymes CYP3A4/5.[3] Both the parent drug and active metabolite are eliminated with a half-life of about 2 hours.[3]
Chemistry
Artemether is a
methylether derivative of
artemisinin, which is a peroxide-containing
lactone isolated from the antimalarial plant Artemisia annua. It is also known as dihydroartemisinin methyl ether, but its
correct chemical nomenclature is (+)-(3-alpha,5a-beta,6-beta,8a-beta, 9-alpha,12-beta,12aR)-decahydro-10-methoxy-3,6,9-trimethyl-3,12-epoxy-12H-pyrano(4,3-j)-1,2-benzodioxepin.
It is a relatively lipophilic and unstable drug,[20] which acts by creating reactive free radicals in addition to affecting the membrane transport system of the plasmodium organism.[13]
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^Piola P, Nabasumba C, Turyakira E, Dhorda M, Lindegardh N, Nyehangane D, et al. (November 2010). "Efficacy and safety of artemether-lumefantrine compared with quinine in pregnant women with uncomplicated Plasmodium falciparum malaria: an open-label, randomised, non-inferiority trial". The Lancet. Infectious Diseases. 10 (11): 762–769.
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^Kiang TK, Wilby KJ, Ensom MH (February 2014). "Clinical pharmacokinetic drug interactions associated with artemisinin derivatives and HIV-antivirals". Clinical Pharmacokinetics. 53 (2): 141–153.
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abStover KR, King ST, Robinson J (April 2012). "Artemether-lumefantrine: an option for malaria". The Annals of Pharmacotherapy. 46 (4): 567–577.
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