Chemoprophylaxis of malaria

Q38 Chemoprophylaxis of malaria with mefloquine can be undertaken with caution in ... 

Acute malaria PO In combination with sulfonamide-. 25 mg daily for 2 days with a sulfonamide Without concomitant sulfonamide-. 50 mg for 2 days Chemoprophylaxis of malaria PO 25 mg once weekly. 

Chloroquine has been the drug of choice for both treatment and chemoprophylaxis of malaria since the 1940s, but its usefulness against P falciparum has been seriously compromised by drug resistance. It remains the drug of choice in the treatment of sensitive P falciparum and other species of human malaria parasites. 

Clindamycin (see Chapter 44) is slowly active against erythrocytic schizonts and can be used after treatment courses of quinine, quinidine, or artesunate in those for whom doxycycline is not recommended, such as children and pregnant women. Azithromycin (see Chapter 44) also has antimalarial activity and is now under study as an alternative chemoprophylactic drug. Antimalarial activity of fluoroquinolones has been demonstrated, but efficacy for the therapy or chemoprophylaxis of malaria has been suboptimal. 

A derivative, chlorproguanil, is similarly effective in chemoprophylaxis of malaria tropica (SEDA-20, 260). 

Pyrimethamine (25 mg once weekly) is indicated in chemoprophylaxis of malaria due to susceptible strains of... 

Nivaquine Detoxification Introduced in 1946, Nivaquine (Chloroquine sulfate) was largely used in the chemoprophylaxis of malaria. Because of the narrow margin between its therapeutic and toxic dose, fatal chloroquine... 

M., Pyrimethamine sustained release systems based on bioresorbable polyesters for chemoprophylaxis of rodent malaria,... 

Prevention of malaria comprises exposure prophylaxis and chemoprophylaxis. 

In a placebo-controlled study of chemoprophylaxis for malaria, 701 Tanzanian infants were assigned to intermittent pyrimethamine + sulfadoxine (under 5 kg, a quarter of a tablet 5-10 kg, half a tablet over 10 kg, one tablet each tablet contained pyrimethamine 25 mg plus sulfadoxine 500 mg) alongside routine childhood immunizations and iron supplementation at 2, 3, and 9 months of age (4). The combination was well tolerated, with no reported adverse events. Episodes of clinical malaria fell by 59% (95% Cl = 41, 72) and the incidence of severe anemia by 50% (95% Cl = 8, 73%) in the first year of life. Contrary to previous studies involving continuous prophylaxis in infants, there was no increase in the frequency of rebound episodes of malaria up to 18 months of age, suggesting that the development of malaria-specific immunity was unimpaired. Responses to vaccines were unaffected. 

Pyrimethamine and proguanil are used as oral antimalarials.and inhibit the utilization of folate by the malarial parasite, so are valuable in chemoprophylaxis and in preventing the transmission of malaria. (See ANTIMALARIALS.) Trimethoprim is a useful antibacterial, and as an antiprotozoal in antimalarial therapy. The selectivity of these agents derives, in part, from the fact that whereas mammals can obtain folic acid from the diet, bacteria and the asexual forms of the malarial parasite must synthesize it. Also, the dihydrofolate reductase enzyme in humans is less sensitive to these drugs than that of the parasites. 

Amodiaqnine is a congener of chlorqnine that is no longer recommended for chemoprophylaxis of fnlciparum malaria. It canses agrannlocytosis and hepatic toxicity. 

Mberu EK, Wansor T, Sato H, Nishikawa Y, Watkins WM. Japanese poor metabolizers of proguanil do not have an increased risk of malaria chemoprophylaxis breakthrough. Trans R Soc TropMedHyg (1995) 89,658-9. 

Black RH. Malaria in die Australian army in South Vietnam. Successful use of a pr< uanil-dapsone combination for chemoprophylaxis of chloroquine-resislant Mciparum malaria. Med... 

All travelers to endemic areas should be advised to remain in well-screened areas, to wear clothes that cover most of the body, and sleep in mosquito nets. Travelers should adhere to malaria chemoprophylaxis regimens and carry the insect repellant DEET (N, N,-diethylmetatoluamide) or other insect sprays containing DEET for use in mosquito-infested areas. 

Kain KC, Shanks D, and Keystone JS. Malaria chemoprophylaxis in the age of drug resistance. I. Currently recommended drug regimens. Clin Infect Dis 2001 33 226-234. 

Standard chemoprophylaxis does not prevent a relapse of vivax or ovale malaria, because the hypnozoite forms of these parasites are not eradicated by chloroquine or other available agents. To markedly diminish the likelihood of relapse, some authorities advocate the use of primaquine after the completion of travel to an endemic area. 

Mefloquine (125 or 250 mg/week n — 56) has been compared with proguanil (100 or 200 mg/day n — 57) for short-term (6 months) malaria chemoprophylaxis in Nigerians with sickle cell anemia in a non-blinded, randomized study (9). Efficacy was similar (89% for mefloquine and 82% for proguanil). Adverse events were reported by 32% of those who took proguanil and 20% of those who took mefloquine. Surprisingly, only 3.6% of the mefloquine group reported neuropsychiatric adverse events. 

Peragallo MS, Sabatinelli G, Sarnicola G. Compliance and tolerability of mefloquine and chloroquine plus proguanil for long-term malaria chemoprophylaxis in groups at particular risk (the military). Trans R Soc Trop Med Hyg 1999 93(l) 73-7. 

Malaria represents the most devastating disease in terms of human suffering and economics. It affects the largest number of people (between 300 and 500 million new infections are reported annually) in the world, with more than 2 million deaths worldwide. In the United States, deaths from malaria are preventable. The primary reasons for deaths are failure to take chemoprophylaxis, inappropriate chemoprophylaxis, delay in seeking medical care, and... 

Another alternative regimen for chemoprophylaxis is the combination of atovaquone and proguanil (Malarone) 1 tablet daily beginning 1 to 2 days prior to travel and continuing for the duration of stay and 1 week after leaving the area. Daily primaquine 15 mg (base) also has been recommended for prophylaxis for both P. vivax and P falciparum malaria. ... 

Prevosto, J.M. Beraud, B. Cheminel, V. Gaillard, Y Mounier, C. Chaulet, J.F. Determination of doxycycline in human plasma and urine samples by high performance liquid chromatography. Application for drug monitoring in malaria chemoprophylaxis. Ann.Biol.Clin.(Paris), 1995, 53, 29-32... 

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