Sulfadimidine

Dose reduction may be needed. Severe: Contraindicated.

Dose reduction may be needed. Severe: Contraindicated.

Severe renal or hepatic failure; blood disorders; hypersensitivity to sulfonamides; acute porphyria; SLE. Pregnancy (3rd trimester) and lactation; infants ≤2 mth.

Renal or hepatic impairment; history of allergy or asthma; AIDS; G6PD deficiency; elderly; ensure adequate fluid intake to reduce risk of crystalluria.

Nausea, vomiting, anorexia, diarrhoea, hypersensitivity reactions, SLE, serum sickness-like syndrome, liver necrosis and hepatomegaly, myocarditis, pulmonary eosinophilia and fibrosing alveolitis, vasculitis, hypoglycaemia, hypothyroidism, neurological reactions, jaundice and kernicterus in premature neonates. Pseudomembranous colitis.
Potentially Fatal: Stevens-Johnson syndrome; toxic epidermal necrolysis; blood dyscrasias; anaphylaxis.

Potentiates effects of oral anticoagulants, methotrexate, phenytoin. Compounds that render the urine acidic increase risk of crystalluria.
Potentially Fatal: Increased blood dyscrasias with clozapine.

Interference with tests for urea, creatinine, urinary glucose, urobilinogen.

Description:
Mechanism of Action: Sulfadimidine is a short-acting sulfonamide. It interferes with the synthesis of nucleic acids in sensitive organisms by blocking the conversion of p-aminobenzoic acid (PABA) to the co-enzyme dihydrofolic acid. Its action is bacteriostatic, although it exerts bactericidal effects where concentrations of thymine are low in the surrounding medium. It has been used with other sulfonamides, e.g. sulfamerazine and sulfadiazine. In veterinary medicine, it is sometimes used with baquiloprim or trimethoprim. Sulfadimidine is used to determine acetylator status due to its pharmacokinetic differences in fast and slow acetylators.
Pharmacokinetics:
Absorption: Well absorbed from GI tract.
Distribution: Protein binding: 80-90%.
Excretion: Half life: 1.5-4 hr (fast acetylators); 5.5-8.8 hr (slow acetylators).

Sulphonamides