Antiprotozoal Agents Cheat Sheet
MALARIA
Malaria is a parasitic disease that has killed hundreds of millions of people and even changed the course of history. The progress of several African battles and the building of the Panama Canal were altered by outbreaks of malaria.
Antiprotozoal Agents | |
Anti-Malarials | Other Anti-Protozoal |
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Even with the introduction of drugs for the treatment of this disease, it remains endemic in many parts of the world. The only known method of transmission of malaria is through the bite of a female Anopheles mosquito, an insect that harbors the protozoal parasite and carries it to humans. Four protozoal parasites, all in the genus Plasmodium, have been identified as causes of malaria:
Antimalarials Dosage Guideline | ||
Drug Name | Dosage/Route | Usual Indications |
Chloroquine (Aralen) | Suppression: Adult: 300 mg PO every week beginning 1–2 wk before exposure and continuing for 4 wk after leaving endemic area Pediatric: 5 mg/kg/wk PO, using same schedule as for an adult Acute attacks: Adult: 600 mg PO, followed by 300 mg PO in 6 h; then 300 mg PO on days 2 and 3 Pediatric: 10 mg/kg PO, followed by 5 mg/kg PO in 6 h and on days 2 and 3 | Prevention and treatment of Plasmodium malaria; treatment of extraintestinal amebiasis |
Hydroxychloroquine | Suppression: Adult: 310 mg PO every week, beginning 1–2 wk before exposure and continuing for 4 wk after leaving endemic area Pediatric: 5 mg/kg/wk, following adult schedule Acute attack: Adult: 620 mg PO, followed by 310 mg PO in 6 h and on days 2 and 3 Pediatric: 10 mg/kg PO, followed by 5 mg/kg PO in 6 h and on days 2 and 3 | Treatment of Plasmodium malaria in combination with other drugs, particularly primaquine |
Mefloquine (Lariam) | Treatment: Adult: 1250 mg PO as a single dose Prevention: Adult: 250 mg PO once weekly, starting 1 wk before travel and continuing for 4 wk after leaving endemic area Pediatric: 15–19 kg,1/4 tablet; 20–30 kg, 1/2 tablet; 31–45 kg, 3/4 tablet; [1]45 kg, 1 tablet; once a week, starting 1 wk before travel and continuing until 4 wk after leaving area | Prevention and treatment of Plasmodium malaria in combination with other drugs |
Primaquine (generic) | Adult: 26.3 mg/d PO for 14 d Pediatric: 0.5 mg/kg per day PO for 14 d; begin therapy during last 2 wk of (or after) therapy with chloroquine or other drugs | Prevention of relapses of P. vivax and P. malariae infections; radical cure of P. vivax malaria |
Pyrimethamine (Daraprim) | Prevention: Adult: 25 mg PO every week Pediatric ([1]10 yr): same as adult Pediatric (4–10 yr): 12.5 mg PO every week Pediatric ( 4 yr): 6.25 mg PO every week Toxoplasmosis: Adult: 50–75 mg/d PO with 1–4 g of a sulfonamide, for 4–5 wk Pediatric: 1 mg/kg/d PO, divided into two equal doses, for 2–4 d; then cut dose in half and continue for 1 mo | Prevention of Plasmodium malaria, in combination with other agents to suppress transmission; treatment of other agents to suppress transmission; treatment of |
ANTIMALARIALS
Antimalarial drugs (Table 12.1) are usually given in combination form to attack the Plasmodium at various stages of its life cycle. Using this approach, it is possible to prevent the acute malarial reaction in individuals who have been infected by the parasite.
These drugs can be schizonticidal (acting against the red-blood-cell phase of the life cycle), gametocytocidal (acting against the gametocytes), sporontocidal (acting against the parasites that are developing in the mosquito), or work against tissue schizonts as prophylactic or antirelapse agents.
Quinine (generic) was the first drug found to be effective in the treatment of malaria; it is no longer available. Antimalarials used today include chloroquine (Aralen), hydroxychloroquine (Plaquenil), mefloquine (Lariam), primaquine (generic), and pyrimethamine (Daraprim). Fixeddose combination drugs for malaria prevention and treatment are discussed in Box 12.2.