Last update Jan. 30, 2022



Safe substance and/or breastfeeding is the best option.


This diaminopyrimidine antagonist of folic acid is used together with a sulphonamide (sulfadoxine) in the prevention and treatment of malaria and in the treatment of toxoplasmosis. Single-dose oral administration, a single dose (which can be repeated after a few days) for malaria, and daily for toxoplasmosis.

It is excreted in human milk in an amount that could be clinically significant (Edstein 1986, Clyde 1956) and serve as a treatment for infant malaria. (Clyde 1960 and 1956)

Infants of malaria-affected mothers who took it had no clinical problems. (Kuemmerle 2020, Clyde 1960 and 1956)

Its use is authorized in infants from two months of age (AEMPS 2020), so it is unlikely that the lower dose that passes through the mothers’ milk could affect the infant. Evaluate folic acid supplementation in prolonged treatments.

Avoid in glucose-6-phosphate-dehydrogenase deficiency. (WHO-UNICF 2002)

WHO List of Essential Medicines 2002: compatible with breastfeeding in healthy newborns, avoid, if possible, in premature infants and children under one month due to the risk of jaundice. (WHO 2010 and 2002)

American Academy of Pediatrics: medication usually compatible with breastfeeding. (AAP 2001)

See below the information of this related product:

  • Sulfadoxine (Fairly safe. Mild or unlikely adverse effects. Compatible under certain circumstances. Follow-up recommended. Read Commentary.)


Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Pyrimethamine is also known as

Pyrimethamine in other languages or writings:


Pyrimethamine belongs to this group or family:


Main tradenames from several countries containing Pyrimethamine in its composition:

  • Daraprim
  • Fansidar™. Contains other elements than Pyrimethamine in its composition
  • Pyramet™. Contains other elements than Pyrimethamine in its composition


Variable Value Unit
Oral Bioavail. 100 %
Molecular weight 249 daltons
Protein Binding 87 (80 - 90) %
pKa 17.2 -
Tmax 2 - 6 hours
85 - 96 hours
M/P ratio 0.2 - 0.4 -
Theoretical Dose 0.1 - 0.5 mg/Kg/d
Relative Dose 8 - 40 %
Ped.Relat.Dose 10 - 50 %


  1. AEMPS-SB. Pirimetamina. Ficha técnica. 2020 Full text (in our servers)
  2. Kuemmerle A, Schmid C, Kande V, Mutombo W, Ilunga M, Lumpungu I, Mutanda S, Nganzobo P, Ngolo D, Kisala M, Valverde Mordt O. Prescription of concomitant medications in patients treated with Nifurtimox Eflornithine Combination Therapy (NECT) for T.b. gambiense second stage sleeping sickness in the Democratic Republic of the Congo. PLoS Negl Trop Dis. 2020 Jan 27;14(1):e0008028. Abstract Full text (link to original source)
  3. Saito M, Gilder ME, McGready R, Nosten F. Antimalarial drugs for treating and preventing malaria in pregnant and lactating women. Expert Opin Drug Saf. 2018 Nov;17(11):1129-1144. Abstract Full text (link to original source) Full text (in our servers)
  4. WHO. Guidelines for the treatment of malaria. 2nd ed. Geneva: WHO, 2010 2nd ed. Geneva: WHO, 2010 Full text (link to original source) Full text (in our servers)
  5. GSK. Pyrimethamine Drug Summary. 2003 Full text (in our servers)
  6. WHO / UNICEF. BREASTFEEDING AND MATERNAL MEDICATION Recommendations for Drugs in the Eleventh WHO Model List of Essential Drugs. Department of Child and Adolescent Health and Development (WHO/UNICEF) 2002 Abstract Full text (link to original source) Full text (in our servers)
  7. AAP - American Academy of Pediatrics Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics. 2001 Sep;108(3):776-89. Abstract Full text (link to original source) Full text (in our servers)
  8. Edstein MD, Veenendaal JR, Newman K, Hyslop R. Excretion of chloroquine, dapsone and pyrimethamine in human milk. Br J Clin Pharmacol. 1986 Dec;22(6):733-5. Abstract Full text (link to original source)
  9. CLYDE DF. Prolonged malaria prophylaxis through pyrimethamine in mothers' milk. East Afr Med J. 1960 Oct;37:659-60. No abstract available. Abstract
  10. CLYDE DF, PRESS J, SHUTE GT. Transfer of pyrimethamine in human milk. J Trop Med Hyg. 1956 Dec;59(12):277-84. No abstract available. Abstract

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