Malaria treatment regimens

In endemic areas malaria should always be considered and, if possible, checked by blood film analysis otherwise empiric antimalarial treatment may be indicated (see section on malaria). Empiric treatment should further cover the spectrum of bacterial agents likely to cause septic infections in the particular patient. The potentially fatal course of septic disease requires an antibiotic regimen that is rapidly lethal for the causative agent, and preferably attains adequate levels at the site of infection quickly. Therefore, treatment regimens usually include a combination of two (sometimes three) antibiotics that are given by a parenteral route (intramuscularly or preferably by intravenous infusion). 

Treatment regimens vary in detail those quoted here accord with the recommendations in the British National Formulary 2002, and the BNF is a good source of contact numbers, addresses and websites to obtain expert advice on therapy and prophylaxis of malaria. 

In many malaria endemic countries, artemisinin-based combination therapies (ACTs) are now established as standard treatment regimens for falciparum malaria, the most lethal form of malaria which still causes more than one million deaths annually throughout the world. However, recent reports of parasite resistance to artemisinins in four countries of the Greater Mekong subregion, Cambodia, Myanmar, Thailand and Vietnam underlie the importance of continuous surveillance of therapeutic efficacy of ACTs as a tool of national malarial drug policies [1 ]. 

When advising potential travelers on prophylaxis for malaria, be aware of the incidence of chloroquine-resistant P. falciparum malaria and the countries where it is prevalent. In patients who have P. vivax or P. ovale malaria (note that some patients can have P. falciparum and one of these species), following the treatment of the acute phase of malaria and screening for glucose-6-phosphate dehydrogenase deficiency, patients should receive a regimen of primaquine for 14 days to ensure eradication of the hypnozoite stage of P. vivax or P. ovale. For detailed recommendations for prevention of malaria go to www.cdc.gov/travel/. 

Malaria parasite has developed resistance to many of these so-called quinoline antimalarials rendering them completely obsolete. This situation has forced the use of combination regimens that consists of a mixture of two or more antimalarial active ingredients this approach has proven to work better than monotherapies, but often is only a temporary soulu-tion. Nevertheless, quinine remains a very effective drug, with only few treatment failures or resistance reported around the globe. 

Sulfonamides, such as sulfadiazine, in combination with pyrimethamine, are considered the treatment of choice of symptomatic toxoplasmosis. Patients should be well hydrated to prevent crystalluria this problem may be reduced with the use of triple sulfas (trisulfapyrimidine). Some regimens have included a sulfonamide (sul-fadoxine) in combination with pyrimethamine (Fansidar) for the treatment of chloroquine-resistant malaria caused by P. falciparum. 

Mefloquine is effective in treating most falciparum malaria. The drug is not appropriate for treating individuals with severe or complicated malaria, since quinine, quinidine, and artemisinins are more rapidly active, and since drug resistance is less likely with those agents. The combination of artesunate plus mefloquine showed excellent antimalarial efficacy in regions of Southeast Asia with some resistance to mefloquine, and this regimen is now one of the combination therapies recommended by the WHO for the treatment of uncomplicated falciparum malaria (Table 52-4). Artesunate-mefloquine is the first-line therapy for uncomplicated malaria in a number of countries in Asia and South America. 

Inhibitors of enzymes involved in folate metabolism are used, generally in combination regimens, in the treatment and prevention of malaria. 

The relative efficacy and safety of artemisinin-based combination therapies are now under active investigation. In general, the leading regimens are highly efficacious, safe, and well tolerated, and they are the new standard of care for the treatment of uncomplicated falciparum malaria. 

In a double-blind, randomized, placebo-controlled trial in Gambian children with uncomplicated falciparum malaria treated with pyrimethamine + sulfadoxine (25/ 500 mg n — 600) or pyrimethamine + sulfadoxine combined with two regimens of oral artesunate (4 mg/kg, n — 200 or 4 mg/kg od for 3 days, n — 200), there were mild adverse events, such as headache, anorexia, nausea, vomiting, abdominal pain, and diarrhea, in a high proportion of children (56%) (17). Combination treatment with... 

Smithuis FM, van Woensel JB, Nordlander E, Vantha WS, ter Kuile FO. Comparison of two mefloquine regimens for treatment of Plasmodium falciparum malaria on the northeastern Thai-Cambodian border. Antimicrob Agents Chemother 1993 37(9) 1977-81. 

Sulfadiazine, a sulfonamide antibiotic, is used in rheumatic fever prophylaxis, as an alternative to penicillin, as an adjunctive regimen in treatment of toxoplasmosis, and in uncomplicated attacks of malaria (see also Figure 90). 

Regimens for Malaria Chemoprophylaxis and Self-Treatment in Nonimmune Individuals ... 

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