SELECTED ANTI-MALARIAL DRUGS: IMPORTANT INFORMATION

Primaquine:

Use:  Pramaquine is 8-aminoquinoline highly active against gametocytes of all malaria species. It is also effective against hypnozoites of the relapsing malarial parasites of P. vivax. It is the only drug currently used for treatment of relapsing malaria. It is used along with chloroquine in P. vivax infections as an anti-relapse therapy and in P. falciparum infections as a gametocytocidal drug (mature gametocytes of P. falciparum are unaffected by chloroquine).

Dose:  P. vivax: 0.25 mg base per Kg body weight per day for 14 days.
            P. falciparum: 0.75 mg / Kg body weight as single dose.

Primaquine may be given concurrently with an active blood Schizonticide, such as chloroquine.

Side Effects: it can cause a fatal hemolytic crisis in patients with glucose-6-phosphate dehydrogenase deficiency. The symptoms are dose related and are relatively rare at daily dose of 0.25 mg of base per Kg body weight (15 mg of base daily in adult). The symptoms include nausea, vomiting, abdominal pain and cramps. It can also cause granulocytopenia. Patients should be warned to stop treatment and seek medical advice if they have abdominal pain, become weak or pale or notice darkening of urine. Gastric intolerance can be avoided by administering the drug with food.

Contra-indications: Primaquine should not be used in children below 04 years of age and in pregnant women, due to risk of hemolysis. It should also not be used in conditions pre-disposing to granulocytopenia, including active rheumatoid arthritis and lupus erythematosus . Primaquine should not be administered with any other drug that may induce hematological disorders.

Over Dosage: Weakness, cyanosis, nausea, vomiting, hemolytic anemia, jaundice and bone marrow depression may occur with over dosage. There is no specific antidote and treatment is symptomatic.

Pre-cautions: Primaquine should be used very carefully in known G6PD deficient patients. Patients should be warned to stop treatment and seek medical advice if they have abdominal pain, become weak or pale or notice darkening of urine.