Sulfadoxine

(BAN, USAN, rINN)
Synonyms: Ro-4-4393; Sulfadoksiini; Sulfadoksinas; Sulfadoxin; Sulfadoxina; Sulfadoxinum; Sulformethoxine; Sulforthomidine; Sulphormethoxine; Sulphorthodimethoxine; Szulfadoxin. N 1 -(5,6-Dimethoxypyrimidin-4-yl)sulphanilamide.
Cyrillic synonym: Сульфадоксин.

💊 Chemical information

Chemical formula: C12H14N4O4S = 310.3.
CAS — 2447-57-6.
ATC Vet — QJ0 1EQ13.

Pharmacopoeias.

In Chin., Eur., Int., US, and Viet.

Ph. Eur. 6.2

(Sulfadoxine). White or yellowish-white crystalline powder or crystals. Very slightly soluble in water; slightly soluble in alcohol and in methyl alcohol. It dissolves in solutions of alkali hydroxides and in dilute mineral acids. Protect from light.

USP 31

(Sulfadoxine). Protect from light.

💊 Adverse Effects, Treatment, and Precautions

As for Sulfamethoxazole. For reference to the adverse effects of a combination of sulfadoxine and pyrimethamine, see Pyrimethamine. If adverse effects occur, sulfadoxine has the disadvantage that several days are required for elimination from the body.

💊 Interactions

💊 Antimicrobial Action

As for Sulfamethoxazole. Synergy exists between sulfadoxine and pyrimethamine, which act against folate metabolism at different points of the metabolic cycle. Resistance to the combination of sulfadoxine and pyrimethamine in plasmodia, first noted in Thailand in the late 1970s, has become widespread in many malarious areas of the world. For further details of resistance to antimalarial drugs.

💊 Pharmacokinetics

Sulfadoxine is readily absorbed from the gastrointestinal tract. High concentrations in the blood are reached in about 4 hours; the half-life in the blood is about 4 to 9 days. About 90 to 95% is reported to be bound to plasma proteins. Sulfadoxine is widely distributed to body tissues and fluids; it passes into the fetal circulation and has been detected in low concentrations in breast milk. Sulfadoxine is excreted very slowly in urine, primarily unchanged.

💊 Uses and Administration

Sulfadoxine is a long-acting sulfonamide that has been used in the treatment of various infections but is now rarely used alone. It is given as a fixed-dose combination of 20 parts sulfadoxine with 1 part pyrimethamine (Fansidar, Roche) in the treatment of falciparum malaria resistant to other therapies, usually after a course of quinine. Although the combination has been used in the prophylaxis of malaria, the risk of toxicity is now generally considered to outweigh its value. In the treatment of malaria, the usual oral dose is 1.5 g of sulfadoxine with 75 mg of pyrimethamine as a single dose; this should not be repeated for at least 7 days. Oral doses for children are: 5 to 10 kg bodyweight, 250 mg sulfadoxine with 12.5 mg pyrimethamine; 11 to 20 kg, 500 mg sulfadoxine with 25 mg pyrimethamine; 21 to 30 kg, 750 mg sulfadoxine with 37.5 mg pyrimethamine; 31 to 45 kg, 1 g sulfadoxine with 50 mg pyrimethamine. Sulfadoxine with pyrimethamine has also been given intramuscularly. Sulfadoxine with pyrimethamine has also been tried in the treatment of actinomycetomas, and for prophylaxis of pneumocystis pneumonia in immunocompromised patients. A mixture of 5 parts of sulfadoxine with 1 part trimethoprim is used in veterinary medicine.

💊 Preparations

USP 31: Sulfadoxine and Pyrimethamine Tablets.

Proprietary Preparations

Malaysia: Fansidar. Multi-ingredient: Austral.: Fansidar; Belg.: Malastop†; Braz.: Fansidar; Canad.: Fansidar†; Denm.: Fansidar†; Fr.: Fansidar; India: Artemal†; Laridox; Pyralfin; Rimodar; Indon.: Fansidar; Suldox; Irl.: Fansidar; Israel: Fansidar; Malaysia: Madomine; Philipp.: Fansidar; S.Afr.: Fansidar; Singapore: Madomine†; Switz.: Fansidar; Fansimef†; Thai.: Vivaxine†; UK: Fansidar; USA: Fansidar.
Published May 08, 2019.