The choice of which drug to use to treat malaria depends on where the patient acquired malaria (i.e. whether chloroquine resistance is common or not), whether prophylaxis was taken, and what form of malaria the patient has.
If the patient has P. vivax, P ovale, P. malariae, or has been in an area where there is no chloroquine resistance in P. falciparum, chloroquine is the best drug to use to treat malaria.
If the patient is infected with P. vivax or P. ovale, primaquine needs to be given as well. This drug is able to kill the liver stages of the parasites, unlike chloroquine. If primaquine is not used, the chloroquine will cure the acute attack, but the dormant liver stages will be able to cause recurrences in the future.
In cases where chloroquine resistant P. falciparum is suspected, either quinine, mefloquine, halofantrine or the artemesinins can be used. Parasites that are resistant to mefloquine are also often resistant to halofantrine. Mefloquine is also not licensed for use as treatment in South Africa. Halofantrine has been associated with cardiac side effects, and should not be used for routine treatment. Quinine was the first drug used to successfully treat malaria, and with increasing chloroquine resistance, it is making something of a “comeback”. It is thought to be the best available agent for treating complicated chloroquine resistant falciparum malaria. Unfortunately, resistance to this drug is also being described.
A new class of drug is the artemesinin derivatives. This drug has been known for centuries in China and is derived from the wormwood plant. It shows great potential in being able to treat resistant falciparum malaria, and has been used often in SE Asia. Unfortunately, resistance to this agent is also being described. When these drugs are used to treat malaria, they should be combined with a second agent to try and reduce the development of resistance.
In South Africa, treatment is usually with either an artemesinin derivative called artemether in combination with lumefantrine (Coartem), or with quinine combined with doxycycline. The artemether/lumefantrine combination has been used since 2001 in Kwazulu Natal with good results. It can be used for uncomplicated malaria if the patient is able to take medication orally. For severe or complicated malaria, quinine given intravenously is still the recommended treatment in South Africa.