| PRIMAQUINE PHOSPHATE
Classifications: antimalarial; Therapeutic: antimalarial
Pregnancy Category: C
26.3 mg tablets; 5 g, 25 g, 100 g, 500 g powder
Acts on primary exoerythrocytic forms of Plasmodium vivax and Plasmodium falciparum by an incompletely known mechanism. Destroys late tissue forms of P. vivax and thus effects radical cure (prevents relapse).
Gametocidal activity against all species of Plasmodia that infect humans; interrupts transmission of malaria.
To prevent relapse ("radical" or "clinical" cure) of P. vivax and P. ovale malarias and to prevent attacks after departure from areas where P. vivax and P. ovale malarias are endemic. With clindamycin for the treatment of Pneumocystis carinii pneumonia (PCP) in AIDS.
Hypersensitivity to primaquine or iodoquinol; rheumatoid arthritis; lupus erythematosus (SLE); hemolytic drugs, concomitant
or recent use of agents capable of bone marrow depression (e.g., quinacrine; patients with G6PD deficiency); pregnancy (category
Bone marrow depression; hematologic disease; methemoglobin reductase deficiency.
Route & Dosage
Adult: PO 30 mg daily for 14 d concomitantly or consecutively with chloroquine or hydroxychloroquine on first 3 d of acute attack
Child: PO 0.5 mg/kg daily for 14 d concomitantly or consecutively with chloroquine or hydroxychloroquine on first 3 d of acute attack
Adult: PO 15 mg daily for 14 d beginning immediately after leaving malarious area
Child: PO 0.3 mg/kg daily for 14 d beginning immediately after leaving malarious area
- Give drug at mealtime or with an antacid (prescribed); may prevent or relieve gastric irritation. Notify physician if GI
- Store in tight, light-resistant containers.
Adverse Effects (≥1%)Hematologic: Hematologic reactions including granulocytopenia and acute hemolytic anemia in patients with G6PD deficiency,
moderate leukocytosis or leukopenia
, granulocytopenia, agranulocytosis. GI:
Nausea, vomiting, epigastric distress, abdominal cramps. Skin:
Methemoglobinemia (cyanosis). Body as a Whole:
Headache, confusion, mental depression
. Special Senses:
Disturbances of visual accommodation. CV:
Hypertension, arrhythmias (rare).
of both quinacrine
and primaquine increased.
Readily from GI tract. Peak:
6 h. Metabolism:
Rapidly in liver to active metabolites. Elimination:
In urine. Half-Life:
Assessment & Drug Effects
- Be aware drug may precipitate acute hemolytic anemia in patients with G6PD deficiency, an inherited error of metabolism
carried on the X chromosome, present in about 10% of American black males and certain white ethnic groups: Sardinians,
Sephardic Jews, Greeks, and Iranians. Whites manifest more intense expression of hemolytic reaction than do blacks. Screen
for prior to initiation of therapy.
- Lab tests: Perform repeated hematologic studies (particularly blood cell counts and Hgb) and urinalyses during therapy.
Patient & Family Education
- Examine urine after each voiding and to report to physician darkening of urine, red-tinged urine, and decrease in urine
volume. Also report chills, fever, precordial pain, cyanosis (all suggest a hemolytic reaction). Sudden reductions in hemoglobin
or erythrocyte count suggest an impending hemolytic reaction.