Primaquine phosphate
Primaquine phosphate
Primaquine phosphate
( PRIM-ah-kwin)
Pregnancy Category: C (Rx)

Classification: 8-Aminoquinoline, antimalarial

Action/Kinetics: Mechanism of action not known, but the drug binds to and may alter the properties of DNA leading to decreased protein synthesis. Both the gametocyte and exoerythrocyte forms are inhibited. Some gametocytes are destroyed while others cannot undergo maturation division in the gut of the mosquito. Well absorbed from GI tract. Peak plasma levels: 1-3 hr. Poorly distributed in body tissues. t 1/2 elimination: 4 hr. Rapidly metabolized.

Uses: Only for the radical cure of Plasmodium vivax malaria, the prophylaxis of relapse in P. vivax malaria, or following the termination of chloroquine phosphate suppressive therapy in areas where P. vivax is endemic.

Contraindications: Concomitant use with quinacrine. In clients with rheumatoid arthritis or lupus erythematosus who are acutely ill or who have a tendency to develop granulocytopenia. Concomitant use with other bone marrow depressants or hemolytic drugs.

Special Concerns: Use during pregnancy only when benefits outweigh risks.

Side Effects: GI: Abdominal cramps, epigastric distress, N&V.; Hematologic: Leukopenia. Methemoglobinemia in NADH methemoglobin reductase deficient individuals. Blacks and members of certain Mediterranean ethnic groups (Sardinians, Sephardic Jews, Greeks, Iranians) manifest a high incidence of G6PD deficiency and as a result have a low tolerance for primaquine. These individuals manifest marked hemolytic anemia following primaquine administration. Miscellaneous: Headache, pruritus, interference with visual accommodation, cardiac arrhythmias hypertension.

Overdose Management: Symptoms: Abdominal cramps, vomiting, burning and epigastric distress, cyanosis, methemoglobinemia, anemia, moderate leukocytosis or leukopenia, CNS and CV disturbances. Granulocytopenia and acute hemolytic anemia in sensitive clients. Treatment: Treat symptoms.

Drug Interactions: Bone marrow depressants, hemolytic drugs / Additive side effects Quinacrine / Metabolic degradation of primaquine effects. Do not give primaquine to clients who are receiving or have received quinacrine within the past 3 months.

How Supplied: Tablet: 26.3 mg

Dosage
?Tablets Acute attack of vivax malaria, clients with parasitized RBCs.
15 mg (base) daily for 14 days together with chloroquine phosphate (to destroy erythrocytic parasites).
Suppression of malaria.
Adults: 26.3 mg (15 mg base) daily for 14 days or 78.9 mg once a week for 8 weeks; children: 0.5 mg/kg/day (0.3 mg/kg base) for 14 days.