Artemether/lumefantrine, sold under the trade name Coartem among others, is a combination of the two medications artemether and lumefantrine. It is used to treat malaria caused by Plasmodium falciparum that is not treatable with chloroquine. It is not typically used to prevent malaria. It is taken by mouth.
Common side effects include muscle and joint pains, fever, loss of appetite, and headache. Serious side effects include prolonged QT syndrome. While not well studied it appears to be okay in pregnancy. The dose does not need changing in those with mild or moderate kidney or liver problems.
The combination came into medical use in 1992. They were both developed in China. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the developing world is between 0.10 and 1.2 USD per day as of 2014. It is not available as a generic medication and a course of treatment costs between 100 and 200 USD in the United States.
The combination is an effective and well-tolerated malaria treatment, providing high cure rates even in areas of multi-drug resistance.