Sulfadiazine
| Evidence Level: L4 | Predicted Indications: 2 |
Table of Contents
Sulfadiazine: From Bacterial Infections to Pneumocystosis
One-Sentence Summary
Sulfadiazine is a sulfonamide antibacterial agent; however, this evidence pack contains no record of its original approved indication or India market license. The TxGNN model predicts it may be effective for Pneumocystosis, with no registered clinical trials but 20 historical publications supporting a plausible mechanistic and clinical-practice rationale.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not available in evidence pack (no license records; drug not marketed in India) |
| Predicted New Indication | Pneumocystosis |
| TxGNN Prediction Score | 99.39% |
| Evidence Level | L4 |
| India Market Status | Not Marketed |
| Number of Registrations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available (marked as a High-severity data gap in this evidence pack). Based on known pharmacology, Sulfadiazine is a sulfonamide antibiotic that inhibits dihydropteroate synthase (DHPS), blocking bacterial/protozoal folate synthesis — a pathway shared by Pneumocystis jirovecii and Toxoplasma gondii but absent in human cells, which confers selective toxicity.
Historically, pyrimethamine-sulfadiazine combinations have been used as an alternative regimen for AIDS-associated Pneumocystis carinii pneumonia (PCP) and concurrent toxoplasmic encephalitis, particularly when trimethoprim-sulfamethoxazole (TMP-SMX, the current first-line therapy) is not tolerated. This gives the TxGNN prediction a plausible mechanistic basis.
That said, this represents a re-identification of established historical clinical practice from the 1970s–2000s rather than a genuinely novel repurposing signal. No original indication or India licensing data was available in this pack to assess overlap with current approved use.
Clinical Trial Evidence
Currently no related clinical trials registered
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 2645082 | 1989 | Case Series/Report | Clinical Pharmacy | Pyrimethamine-sulfadiazine used for treating PCP and concurrent toxoplasmosis in AIDS patients |
| 5315969 | 1971 | Case Report | Annals of Internal Medicine | Early report of PCP successfully treated with pyrimethamine and sulfadiazine |
| 12645193 | 2002 | Case Report | J Formosan Medical Association | Taiwan case: Toxoplasma brain abscess treated with clindamycin/sulfadiazine, with concurrent atypical PCP |
| 2969023 | 1988 | Review | The Journal of Infectious Diseases | Overview of PCP therapy and prophylaxis strategies |
| 2996829 | 1985 | Review | Clinical Pharmacy | Treatment review of AIDS infectious complications; PCP identified as most common (58%) |
| 29604970 | 2018 | Review | Handbook of Clinical Neurology | CNS Toxoplasma gondii infection in HIV patients; discusses sulfonamide-based prophylaxis/treatment |
| 9097375 | 1997 | Review | Seminars in Respiratory Infections | Review of Toxoplasma pneumonia pathogenesis and treatment in immunocompromised hosts |
| 4580723 | 1973 | Review | Transplantation Proceedings | Diagnosis and treatment of pneumocystosis and toxoplasmosis in the immunosuppressed host |
| 2011633 | 1991 | Review | Primary Care | PCP identified as the most common opportunistic infection in AIDS (>80% of cases) |
| 3914245 | 1985 | Review | Archives Françaises de Pédiatrie | Pediatric PCP; TMP-based treatment discussed, early initiation emphasized |
India Market Information
Sulfadiazine is currently not marketed in India according to this evidence pack (0 registered licenses). No product authorization records are available.
Safety Considerations
- Drug Interactions: 82 documented interactions identified (source: DDInter). All 20 detailed interactions returned are rated Moderate severity and predominantly involve antidiabetic agents — sulfonylureas (e.g., Glimepiride, Glyburide, Glipizide, Chlorpropamide, Tolazamide, Repaglinide, Nateglinide), insulins (all major formulations), and Balsalazide/Picosulfuric acid. Sulfonamides are known to potentiate hypoglycemic effects, so concurrent use with these agents warrants glucose monitoring.
Key warnings and contraindications data are not available in this evidence pack (flagged as a Blocking data gap — TFDA/local package insert warnings and contraindications must be obtained before any safety review can proceed).
Conclusion and Next Steps
Decision: Hold
Rationale: Evidence is limited to historical case reports and narrative reviews (L4, no clinical trials or RCTs), the drug is not currently marketed in India, and a Blocking data gap exists for core safety information (warnings/contraindications), which prevents any S1 safety assessment from being completed.
To proceed, the following is needed:
- Official package insert warnings and contraindications (Blocking gap — required before any safety evaluation)
- Confirmed mechanism of action documentation from DrugBank
- Original approved indication and licensing status verification (currently absent from this pack)
- Assessment of whether modern first-line therapy (TMP-SMX) supersedes the clinical rationale for this repurposing candidate
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.