Sulfadiazine is a sulfonamide antibiotic used to treat a range of bacterial and protozoal infections, especially toxoplasmosis, when used in combination with pyrimethamine. It inhibits dihydropteroate synthase, an enzyme involved in folic acid synthesis, which is critical for microbial DNA and RNA production.
It is primarily administered orally, but intravenous formulations are also used in severe infections.
Indications include:
∙ Toxoplasmosis (in combination therapy)
∙ Urinary tract infections (less common now)
∙ Rheumatic fever prophylaxis (in penicillin-allergic patients)
∙ Nocardiosis and other sulfonamide-sensitive infections
Parent: Sulfadiazine / Sulfadimidine / Sulfamethazine / Sulfaguanidine
Parent: Sulfadiazine
Parent: Sulfadimidine / Sulfadiazine
Parent: Sulfamethoxazole /Sulfadiazine/ Sulfadimethoxine
Parent: Sulfamethoxazole /Sulfadiazine / Sulfadimidine / Sulfadimethoxine
Parent: Sulfadiazine
Impurities in sulfadiazine originate from its chemical synthesis, generally involving the condensation of sulfanilamide with heterocyclic precursors, and from degradation due to heat, light, or moisture. Impurity control is required to meet ICH Q3A/B, USP, and EP standards, especially for parenteral use.
Process-Related Impurities
Degradation Impurities
Elemental Impurities
Analytical Techniques for Impurity Detection
Sulfadiazine is primarily used to treat toxoplasmosis (in combination with pyrimethamine). It is also used for rheumatic fever prophylaxis and select bacterial infections.
It blocks dihydropteroate synthase, inhibiting folic acid synthesis in bacteria and protozoa, ultimately interfering with DNA replication.
Yes. Crystalluria can occur, especially at high doses or with inadequate hydration. Plenty of fluids and alkaline urine help prevent it.
Sulfadiazine is stable under normal conditions, but light and moisture can cause degradation and discoloration. It should be stored in a tight container, protected from light and humidity.
