Adverse reactions
Common side effects of primaquine administration include nausea, vomiting, and stomach cramps.In persons with cytochrome b5 reductase deficiency, primaquine causes methemoglobinemia, a condition in which the blood carries less oxygen that it does normally.Overdosing can reduce the number of function of various kinds of blood cells, including loss of red blood cells, methemoglobinemia, and loss of white blood cells.Persons with glucose-6-phosphate dehydrogenase deficiency (G6PD) may develop hemolytic anemia from primaquine. Pharmacology
Mechanism of action
Primaquine is lethal to P. vivax and P. ovale in the liver stage, and also to P. vivax in the blood stage through its ability to do oxidative damage to the cell. However, the exact mechanism of action is not fully understood. Liver hypnozoites aside, primaquine can possibly eliminate P. vivax merozoites in bone marrow as a result of accumulation there of hydrogen peroxide. Pharmacokinetics
Primaquine is well-absorbed in the gut and extensively distributed in the body without accumulating in red blood cells. Administration of primaquine with food or grapefruit juice increases its oral bioavailibity. In blood, about 20% of circulating primaquine is protein-bound, with preferential binding to the acute phase protein orosomucoid. With a half-life on the order of 6 hours, it is quickly metabolized by liver enzymes to carboxyprimaquine, which does not have anti-malarial activity. Renal excretion of the parent drug is less than 4%. Chemistry
Primaquine is an analog of pamaquine which was the first drug of the 8-aminoquinoline class; tafenoquine is another such drug.
Primaquine is a medication used to treat and prevent malaria and to treat Pneumocystis pneumonia. Specifically it is used for malaria due to Plasmodium vivax and Plasmodium ovale along with other medications and for prevention if other options cannot be used. It is an alternative treatment for Pneumocystis pneumonia together with clindamycin. It is taken by mouth.Common side effects include nausea, vomiting, and stomach cramps. Primaquine should not be given to people with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the risk of red blood cell breakdown. It is often recommended that primaquine not be used during pregnancy. It may be used while breastfeeding if the baby is known not to have G6PD deficiency. The mechanisms of action is not entirely clear but is believed to involve effects on the malaria parasites DNA.Primaquine was first made in 1946. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. Medical uses
Malaria
Primaquine is primarily used to prevent relapse of malaria due to Plasmodium vivax and Plasmodium ovale. It eliminates hypnozoites, the dormant liver form of the parasite, after the organisms have been cleared from the bloodstream. If primaquine is not administered to patients with proven P. vivax or P. ovale infection, a very high likelihood of relapse exists for weeks or months (sometimes years).