Anti-Malarial Drugs: Blood Plasmodia
Review
Plasmodia types and malaria.
Chloroquine:
Causes heme to accumulate in the cells, which is toxic to the parasite.
Unfortunately, Plasmodium falciparum's resistance to this drug is common in some areas.
Chloroquine is used as treatment and prophylaxis of malaria caused by Plasmodium falciparum and Plasmodium malariae.
It is used in combination therapy against Plasmodium vivax and Plasmodium ovale, which produce dormant forms that reside in the liver; chloroquine, which acts only on parasites in the blood, cannot target the liver forms.
Adverse effects include gastrointestinal problems, and some patients report itchiness.
Although rare, retinal toxicity can occur, and vision changes are possible.
Hemolytic anemia can occur in patients with G6PD deficiency.
Atovaquone-proguanil:
These drugs are antifolates: Atovaquone inhibits mitochondrial electron transport in the parasite; proguanil inhibits dihydrofolate reductase.
Used for both treatment of and prophylaxis against Plasmodium falciparum malaria.
Adverse effects include gastrointestinal problems and itching.
Quinine:
Like chloroquine, causes heme to accumulate to toxic levels.
Used in combination with Fansidar or other antimicrobials, against chloroquine-resistant forms of Plasmodium falciparum.
Adverse effects of quinine include cinchonism, which is a condition that manifests with tinnitus, gastrointestinal problems, head ache, fever, and visual disturbances.
Quinine is also associated with cardiotoxicity and hypotension.
Blackwater fever appears to be most common in malarial patients taking quinine and who have G6PD deficiencies.
Blackwater fever is the result of massive hemolysis leading to hemoglobinuria and possible renal failure.
Quinine + Fandisar
Fandisar comprises the drugs pyrimethamine and sulfadoxine.
Fansidar is an antifolate that inhibits nucleic acid synthesis; it is used with quinine as treatment against chloroquine-resistant strains of Plasmodium falciparum.
Quinine + Antibiotics
Doxycycline, tetracycline, or clindamycin
Mechanism of action depends on the antimicrobial involved.
Used with quinine as treatment for or prophylaxis against chloroquine-resistant Plasmodium falciparum.
Adverse effects include those associated with the antibiotics, and gastrointestinal problems are most commonly reported.
Mefloquine:
Uncertain mechanism of action.
Alternative drug used for chloroquine-resistant Plasmodium falciparum prophylaxis and treatment.
This drug is associated with rare but serious neuropsychiatric effects, including dizziness, mood changes, and hallucinations.
Artesunate and artemether:
Derived from the sweet wormwood plant.
They are fast-acting drugs with uncertain mechanisms of action.
Used in combination therapies to treat severe cases of Plasmodium falciparum malaria.
Low toxicity.
Anti-Malarial Drugs: Liver Plasmodia
Primaquine:
Alters the parasites' DNA.
Used in combination with chloroquine to treat malaria caused by Plasmodium vivax and Plasmodium ovale because it kills parasite in the liver, it prevents relapse.
This drug should not be used during pregnancy, and can cause gastrointestinal problems and itching.
It is associated with hemolytic anemia, especially in patients with G6PD deficiency.
