Primaquine is an antimalarial medication that belongs to the 8-aminoquinoline class, primarily used to prevent relapses of Plasmodium vivax and Plasmodium ovale malaria. It was first introduced in the 1940s as one of the earliest drugs effective against the dormant liver stages (hypnozoites) of these parasites. Primaquine works by targeting the liver stages of the malaria parasite, thereby preventing recurrence of infection. It is also used for terminal prophylaxis in individuals exposed to malaria-endemic areas. Due to its mechanism of action, primaquine is often combined with other antimalarials that target the blood stages of the parasite for complete treatment. While highly effective, its use requires caution in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the risk of hemolytic anemia. Over the decades, primaquine has remained a cornerstone in malaria eradication and relapse prevention strategies.
