sulfadiazine

Indications

• treatment of urinary tract infections & nocardiosis
• prophylaxis for rheumatic fever
• adjunctive treatment for toxoplasmosis
• uncomplicated malaria
• asymptomatic meningiococcal carriers
• chorioretinitis

Dosage

• Toxoplasma encephalitis in HIV patients
  • acute therapy:
    • sulfadiazine 1.0-1.5 g QID plus pyrimethamine 50- 100 mg/day for 6 weeks
    • folinic acid 5-10 mg QD to offset hematologic toxicity of pyrimethamine
  • suppressive therapy:
    • sulfadiazine 2-4 g/day plus pyrimethamine 25 mg/day
• congenital toxoplasmosis:
  • newborns & infants < 2 months:
    • 100 mg/kg//day divided every 6 hours
    • plus pyrimethamine 1 mg/kg/day
    • plus folinic acid 5 mg every 3 days
    • duration of therapy 6 months
  • children > 2 months: 20-50 mg/kg QID

Tabs: 500 mg

Pharmacokinetics

• well absorbed orally
• distribution
  • widely distributed:
    • pleural, peritoneal, synovial & ocular fluids
    • total body water
    • readily diffuses into CSF
    • appears in breast milk
• protein binding: 32-56%
• time to peak serum concentration is within 3-6 hours
• metabolized in the liver by N-acetylation
• elimination 1/2life 10 hours
• eliminated in the urine
  • 43-60% as unchanged drug
  • 15-40% as metabolites

elimination via kidney

elimination via liver

1/2life = 10 hours

protein binding = 32-56 %

Adverse effects

• common (> 10%)
  • fever, itching, rash, photosensitivity, dizziness, headache, anorexia, nausea/vomiting, diarrhea
• less common (1-10%)
  • granulocytopenia, leukopenia, thrombocytopenia, aplastic anemia, hemolytic anemia, hepatitis, Lyell's syndrome, Stevens-Johnson syndrome
• uncommon (< 1%)
  • crsytalluria, hematuria, thyroid function disturbance, interstitial nephritis, serum sickness-like reaction, jaundice, acute nephropathy

• drug adverse effects of sulfonamides
• drug adverse effects of diuretics
• drug adverse effects of carbonic anhydrase inhibitor(s)
• drug adverse effects of antihypertensive agents

More general terms

• sulfanilamide

Additional terms

• N5-formyltetrahydrofolate (folinic acid, citrovorum factor, Fusilev)
• pyrimethamine (Daraprim)
• toxoplasmosis

Component of

• sulfadiazine/trimethoprim
• sulfadiazine/sulfamerazine/sulfamethazine
• pyrimethamine/sulfadiazine
• enrofloxacin/silver sulfadiazine/sulfadiazine
• silver sulfadiazine (Silvadene)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=