Sulphadoxine + Pyrimethamine

Indications

Treatment of all forms of malaria due to Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae. The drug is also indicated for suppressive or prophylactic management, particularly in areas where resistance to chloroquine is known to exist.

Pharmacology

Sulphadoxine & Pyrimethamine is an antimalarial agent embodying the concept of synergism. Individually the components of this preparation exert inferior result with higher doses in comparison with that obtained with the combination. Moreover, this preparation is effective against strains that are resistant to other antimalarial agents and the risk of resistance development is minimum with this preparation. It is extremely long acting drug, attacks the different development stages of the parasite and attains effective concentration with a single dose. The protective effect of a single dose lasts for approximately four weeks and this preparation is compatible with other antimalarial drugs and with antibiotics. It does not influence the action of antidiabetic agents.

Dosage And Administration

Curative treatment of malaria with a single dose-

Adults: 2-3 tablets
Children under 4 years: ½ tablets
4-8 years: 1 tablet
9-14 years: 2 tablets

In severe cases, Sulphadoxine & Pyrimethamine can be beneficially combined with quinine.

Suppressive or prophylactic management-

The dose given below should be taken at one time:

For semi-immune subjects (Dose: once every four weeks)-

Adults: 2-3 tablets
Children under 4 years: ½ tablets
4-8 years: 1 tablet
9-14 years: 2 tablets

For non-immune subjects (Dose: Once every two weeks)-

Adults: 2 tablets
Children under 4 years: 1½ tablets
4-8 years: 1 tablet
9-14 years: 1½ tablets

For malaria prophylaxis: The first dose of Sulphadoxine & Pyrimethamine should be taken one or two days before departure for an endemic area in order to protect tolerance, administration should be continued in the above dosage during the stay and also for four weeks after return or as prescribed by the physician.

Interaction

Concurrent administration of other preparations containing folate antagonists (e.g. cotrimoxazole, methotrexate, anticonvulsants) can result in increased impairment of folic acid metabolism, which leads to haematological side effects.

Contraindications

Prophylactic (repeated) use of Pyrimethamine + Sulphadoxine is contraindicated in patients with severe renal insufficiency, marked liver parenchymal damage or blood dyscrasias. Treatment must be immediately discontinued upon the appearance of any mucocutaneous signs or symptoms such as pruritus, erythema, rash, orogenital lesions or pharyngitis.

Side Effects

Sulphadoxine & Pyrimethamine at the recommended dose is well tolerated. Main side effects are given below

Skin reactions: Drug rash, pruritus and slight hair loss have been observed.
Gastro-intestinal reactions: Feeling of fullness, nausea, rarely vomiting, stomatitis.
Haematological reactions: In rare cases, leukopenia, thrombocytopenia, and megaloblastic anemia have been observed.
Other reactions: Fatigue, headache, fever, polyneuritis may occasionally occur.

Pregnancy And Lactation

Sulphadoxine & Pyrimethamine is contraindicated during pregnancy, premature and newborn infants during the first weeks of life and intolerance to sulfonamide. If pregnancy can not be excluded, possible risks should be balanced against therapeutic effect. Both Pyrimethamine and Sulphadoxine are excreted in maternal breast milk. Nursing mother should not take this preparation.

Precautions And Warnings

Impaired renal or hepatic function, folate deficiency, severe allergy or bronchial asthma, G6PD deficiency, pregnancy. Take with plenty of water to prevent crystalluria. Avoid excessive exposure to sun. Discontinue at the first sign of rash. Discontinue if signs of folic acid deficiency develops. Regular CBC monitoring, LFT, analysis of urine for crystalluria when admin for > 3 mth. Take with food to minimise Gi effects (e.g. anorexia and vomiting).