Primaquine

Primaquine phosphate Tablets are indicated for the radical cure (prevention of relapse) of vivax malaria.

• Primaquine phosphate Tablets are recommended only for the radical cure of vivax malaria, the prevention of relapse in vivax malaria, or following the termination of chloroquine phosphate suppressive therapy in an area where vivax malaria is endemic
• Patients suffering from an attack of vivax malaria or having parasitized red blood cells should receive a course of chloroquine phosphate, which quickly destroys the erythrocytic parasites and terminates the paroxysm
• Primaquine phosphate Tablets should be administered concurrently to eradicate the exoerythrocytic parasites
• In adults at a dosage of 1 tablet (equivalent to 15 mg base) daily for 14 days
• Primaquine phosphate Tablets can be taken with or without food
• Administration of Primaquine phosphate Tablets with food may reduce the incidence of gastrointestinal symptoms

Clinical studies of Primaquine phosphate Tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. …

• Known hypersensitivity reactions to primaquine phosphate, other 8-aminoquinolones, or to any component in Primaquine phosphate Tablets
• Severe glucose-6-phosphate dehydrogenase (G6PD) deficiency (see WARNINGS , Hemolytic Anemia )
• Pregnant women (see WARNINGS , Pregnancy )
• Breastfeeding by a lactating woman when the infant is found to be G6PD deficient or if G6PD status is unknown (see WARNINGS , Nursing Mothers ). …

Pharmacodynamics Interactions Quinacrine Concurrent use of quinacrine (mepacrine) and Primaquine phosphate Tablets are contraindicated. Increased toxicity was seen when quinacrine was used with pamaquine, another 8-aminoquinoline (see CONTRAINDICATIONS ). Hemolytic Agents and Methemoglobinemia-Inducing Drugs The concurrent administration of hemolytic agents or methemoglobinemia-inducing drugs and primaquine should be avoided (see PRECAUTIONS ). If the concurrent administration cannot be avoided, close blood monitoring is required. …

Hemolytic Anemia Hemolytic reactions (moderate to severe) may occur in individuals with G6PD deficiency and in individuals with a family or personal history of favism. Areas of high prevalence of G6PD deficiency are Africa, Southern Europe, Mediterranean region, Middle East, South-East Asia, and Oceania. People from these regions have a greater tendency to develop hemolytic anemia due to a congenital deficiency of erythrocytic G6PD while receiving primaquine and related drugs. Due to the risk of hemolytic anemia in patients with G6PD deficiency, G6PD testing must be performed before using primaquine. Before initiating treatment, obtain baseline hemoglobin and hematocrit. …

Gastrointestinal: Nausea, vomiting, epigastric distress, abdominal cramps. Hematologic: Leukopenia, hemolytic anemia, decreased hemoglobin, methemoglobinemia. Hemolytic anemia occurs commonly in patients with G6PD deficiency and may be severe or fatal in patients with severe G6PD deficiency (see WARNINGS ). Methemoglobin levels are usually

Signs and symptoms Symptoms of overdosage of primaquine phosphate include abdominal cramps, vomiting, burning epigastric distress, central nervous system disturbances including headache, insomnia, and cardiovascular disturbances, including cardiac arrhythmia and QT interval prolongation, methemoglobinemia (indicated by cyanosis), moderate leukocytosis or leukopenia, granulocytopenia, and anemia. Acute hemolysis may occur with particular severity in G6PD deficient patients. Management Treatment of overdosage consists of institution of appropriate symptomatic and/or supportive therapy. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.