Pharm

Pyrimethamine Sulfadoxine

search

Pyrimethamine Sulfadoxine, Fansidar

  • See Also
  1. Pyrimethamine
  • Indications
  1. Toxoplasma gondii
  2. Malaria Prophylaxis and Treatment (esp. Plasmodium Falciparum)
    1. Areas with Chloroquine resistance
    2. Not recommended for routine prophylaxis
    3. Treatment in breakthrough Chloroquine Resistance
  • Mechanism
  1. Inhibits Folate synthesis in Bacteria and Parasites
    1. Mammalian cells may obtain Folate from environmental sources and are less reliant on Folate synthesis
  2. Folate (and Tetrahydrofolate or TH4) is a critical Cofactor in Purine (guanine, adenine) and Nucleic Acid synthesis
    1. Sulfadoxine inhibits dihydropteroate synthase
    2. Pyrimethamine inhibits dihydrofolate reductase
  • Medications
  1. Tablet: Pyrimethamine 25 mg and sulfadoxine 500 mg
    1. Taking with food decreases gastric irritation
  • Dosing
  • Prophylaxis
  1. Adult (and age >=14 years)
    1. Pyrimethamine Sulfadoxine 25/500 mg tablet orally each week
  2. Child (age <14 years)
    1. Age 2-11 months: 1/8 tablet orally each week
    2. Age 1-3 years: 1/4 tablet orally each week
    3. Age 4-8 years: 1/2 tablet orally each week
    4. Age 9-14 years: 3/4 tablet orally each week
  • Dosing
  • Treatment
  1. Adult: 75/1500 mg for one dose
  2. Child: Double dose of prophylactic dose
  • Adverse Effects
  1. See Pyrimethamine
  • Resources
  1. Pyrimethamine Sulfadoxine (pdf from FDA access data)
    1. https://www.accessdata.fda.gov/drugsatfda_docs/label/2004/18557slr015_fansidar_lbl.pdf