primaquine (Primachin, Neo-Quipentyl)

Introduction

Tradename: Prymaccone. (primaquine phosphate)

Indications

• Malaria: (Plasmodium vivax, Plasmodium ovale)
• Pneumocystis pneumonia due to Pneumocytis carinii (in combination with clindamycin)

Contraindications

Caution:

• G6PD deficiency
• NADH methemoglobin reductase deficiency
• acutely ill patients who tend to develop granulocytopenia
• concurrent administration of other agents which supress the bone marrow

pregnancy category = -

safety in lactation = -

Dosage

(take with meals)

• Malaria: (Plasmodium vivax or ovale)
  • 26.3 mg PO QD
  • 15 mg/day (base) or 45 mg (base) once weekly for 8 weeks
  • children:
    • 0.3 mg/kg/day (base) (not to exceed 15 mg base/day) for 14 days
    • 0.9 mg/kg/day (base) weekly for 8 weeks (not to exceed 45 mg base/week)
• Pneumocystis carinii
  • 26.3 mg PO QD (15-30 mg QD)
  • used in conjunction with clindamycin 900 mg IV every 8 hours
• do NOT exceed the recommended dosage

Tabs: 26.3 mg (15 mg base)

Pharmacokinetics

• well absorbed after oral administration
• metabolized in the liver to an active metabolite
• 1/2life is 3.7-9.6 hours
• small amount excreted unchanged in the urine

elimination via liver

1/2life = 3.7-9.6 hours

Adverse effects

• common (> 10%)
  • hemolytic anemia, abdominal pain, nausea/vomiting
• less common (1-10%)
  • methemoglobinemia
• uncommon (< 1%)
  • leukopenia, agranulocytosis, arrhythmias, headache, pruritus, leukocytosis, interference with visual accomodation

• drug adverse effects of antimalarials

Mechanism of action

• may interfere with function of Plasmodium DNA

More general terms

• antimalarial

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=4908
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=6135
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3044369
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3044368
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=359247