Sulphadiazine is antibacterial agent, belongs to Sulphonamide. It has a broad spectrum of activity, effective against gram positive, gram negative bacteria and some protozoa.
Indications
Sulphadiazine is primarily indicated in conditions like Chancroid, GI infections, Malaria, Nocardiosis, Pneumonia, Prevention of rheumatic fever recurrence, Respiratory tract infections, Superficial infections, Toxoplasmosis, Urinary tract infection, and can also be given in adjunctive therapy as an alternative drug of choice in Rheumatic fever.
Contraindications
Sulphadiazine is contraindicated in conditions like Renal failure, Porphyrias, Hepatic failure,G6pd deficiency.
Side Effects
The severe or irreversible adverse effects of Sulphadiazine, which give rise to further complications include Granulocytopenia, Nephrotic syndrome, Serum sickness like illness. Sulphadiazine produces potentially life-threatening effects which include Stevens Johnson syndrome. which are responsible for the discontinuation of Sulphadiazine therapy. The signs and symptoms that are produced after the acute overdosage of Sulphadiazine include Crystalluria. The symptomatic adverse reactions produced by Sulphadiazine are more or less tolerable and if they become severe, they can be treated symptomatically, these include Dizziness, Headache, Nausea, Vomiting, Rashes, Reversible oligospermia, Anorexia, Gastric distress, Photosensitivity, Aplastic anemia, Itching, Lyell's syndrome.
Warnings
Sulphadiazine should be used with caution in patients with liver or kidney disease, blood disorders or of any drug allergy. This may makes patients more prone to sunburn, wear protective clothing and (PABA-free) sunscreen when outdoors. It should be used only if clearly needed during pregnancy or lactation.
High Risk Groups
Drug should not be given to Paediatrics, Pregnant Mothers, patients suffering from Kidney dysfunction, patients suffering from Liver Malfunction, and Neonates. If prescribing authority justifies the benefits of the drug against the possible damages he/she should reevaluate them and consult the reference material and previous studies.
Adult Dosage
0.5 to 1 g (0.75 (0.75)) 6 hourly PO — In Conjuction with pyrimethamine 25mg/day and with suplemental folinic acid. Doses could be given 2-4g/day in 3-6 divided doses.
Child Dosage
25 mg/kg (25 (25)) 6 hourly Oral — Maintenance after 2 day IV maintenance doses
25 mg/kg (25 (25)) 6 hourly Slow IV — Maintenance for 2 Days
37.5 mg/kg (38 (37.5)) 6 hourly Oral —
50 mg/kg (50 (50)) 6 hourly Slow IV — Initial
Neonatal Dosage
25 mg/kg (25 (25)) 6 hourly Oral — Maintenance after 2 day IV maintenance doses
25 mg/kg (25 (25)) 6 hourly Slow IV — Maintenance for 2 Days
37.5 mg/kg (38 (37.5)) 6 hourly Oral —
50 mg/kg (50 (50)) 6 hourly Slow IV — Initial
Drug Interactions
Sulphadiazine is known to interact with other drugs, the details of drug interactions is as follows:DrugDetailsSeverityOnsetManagementAscorbic AcidChlorpropamideMethotrexatePhenytoin (Na)ProcaineDecreased effect of sulfonamides with the PABA metabolite of procaine.PyrimethamineTolbutamideTorasemideSulphadiazine, a strong CYP2C9 inhibitor, may increase the serum concentration of Torasemide, a CYP2C9 substrate, by decreasing Torasemide metabolism and clearance. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of Torasemide if Sulphadiazine is initiated, discontinued or dose changed.TrimethoprimWarfarin (Na)Sulphadiazine may decrease the metabolism of Warfarin.ModerateConsider an alternative drug in order to avoid toxicity of Warfarin. Some combinations are specifically contraindicated by manufacturers. Suggested dosage adjustments are also offered by some manufacturers. Please review applicable package inserts. Monitor for increased effects of Warfarin if Sulphadiazine is initiated/dose increased, and decreased effects if Sulphadiazine is discontinued/dose decreased. These interactions are sometimes beneficial and sometimes may pose threats to life. Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
