Generic
Sulphadoxine + Pyrimethamine
3 brands available in the market
At a glance
Sulphadoxine + Pyrimethamine is an antimalarial drug used for the treatment and prophylaxis of malaria caused by Plasmodium falciparum, P. vivax, and P. malariae, especially in chloroquine-resistant areas.
Description
Sulphadoxine + Pyrimethamine is a synergistic antimalarial combination. Sulphadoxine inhibits dihydropteroate synthetase, preventing folic acid synthesis; Pyrimethamine inhibits dihydrofolate reductase, blocking tetrahydrofolate formation. This sequential blockade stops nucleic acid synthesis in Plasmodium parasites, leading to parasite death.
Indications
- Malaria caused by Plasmodium falciparum, P. vivax, P. malariae
- Malaria prophylaxis (especially in chloroquine-resistant areas)
Therapeutic class
Anti-malarial Drugs
Pharmacological class
Sulfonamide + Dihydrofolate Reductase Inhibitor
Pharmacology
Sulphadoxine inhibits dihydropteroate synthetase, preventing conversion of PABA to dihydrofolic acid; Pyrimethamine inhibits dihydrofolate reductase, blocking tetrahydrofolic acid formation. This synergistic action stops nucleic acid synthesis in Plasmodium parasites, causing parasite death.
Mechanism of action
Destroys malaria parasites by blocking two steps in folic acid synthesis.
Dosage
Malaria Treatment (Single Dose):
- Adults: 2-3 tablets
- 9-14 years: 2 tablets
- 4-8 years: 1 tablet
- Under 4 years: ½ tablet
Prophylaxis (Semi-immune, every 4 weeks):
- Adults: 2-3 tablets
- 9-14 years: 2 tablets
- 4-8 years: 1 tablet
- Under 4 years: ½ tablet
Prophylaxis (Non-immune, every 2 weeks):
- Adults: 2 tablets
- 9-14 years: 1½ tablets
- 4-8 years: 1 tablet
- Under 4 years: 1½ tablets
Administration
- Take first dose 1-2 days before travel to endemic areas
- Take with plenty of water (to prevent crystalluria)
- Take with food to minimize GI effects
Missed dose
If you miss a dose, take it as soon as you remember; if almost time for the next dose, skip it.
Side effects
Common Side Effects:
- Skin reactions (rash, pruritus, mild hair loss)
- GI reactions (fullness, nausea, rare vomiting)
- Headache, fatigue, fever, polyneuritis
Serious (Rare):
- Leukopenia, thrombocytopenia, megaloblastic anemia
Precautions & warnings
- Do not use in severe renal insufficiency, marked liver parenchymal damage, or blood dyscrasias
- Caution in folate deficiency, G6PD deficiency, severe allergy or bronchial asthma
- Discontinue at the first sign of rash
- Avoid excessive sun exposure
Contraindications
- Severe renal insufficiency
- Marked liver parenchymal damage
- Blood dyscrasias
- Pregnancy (especially first trimester)
- Neonates (first weeks of life)
Drug interactions
- Folate antagonists (co-trimoxazole, methotrexate, anticonvulsants): Additive effect on folate metabolism, increased hematological side effects
Food interactions
Caution is advised when consuming alcohol with Sulphadoxine + Pyrimethamine; consult your doctor.
Use in pregnancy
Use in Pregnancy: Contraindicated during pregnancy (especially first trimester); do not use in premature and newborn infants; consult your doctor.
Pregnancy Category: D — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Both Pyrimethamine and Sulphadoxine are excreted in breast milk; nursing mothers should not take this preparation; consult your doctor.
Pediatric use
Indicated for children (weight/age-based dosing)
Geriatric use
Caution required in elderly patients
Renal / hepatic impairment
Renal Impairment: Contraindicated in severe renal insufficiency; consult your doctor.
Hepatic Impairment: Contraindicated in marked liver damage; consult your doctor.
Overdose effects
Overdose may cause folate deficiency, blood dyscrasias, nausea, abdominal pain; consider folinic acid administration; provide symptomatic treatment.
Storage conditions
Store below 30°C, away from light and moisture; keep out of reach of children.
Chemical structure
Sulphadoxine + Pyrimethamine