Rifampicin
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Rifampicin: From Pulmonary Tuberculosis to Conjunctivitis
One-Sentence Summary
Rifampicin is a broad-spectrum antibiotic (RNA polymerase inhibitor) originally used to treat pulmonary tuberculosis. The TxGNN model predicts it may be effective for conjunctivitis, but this is supported only by indirect literature (about 19 publications, mostly susceptibility surveys, case reports and a few older topical-use studies) and no registered clinical trials.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Pulmonary tuberculosis |
| Predicted New Indication | Conjunctivitis |
| TxGNN Prediction Score | 0.9995 |
| Evidence Level | L4 |
| India Market Status | Listed in a compiled Indian medicine price dataset (at least 20) – CDSCO approval status is not included in this data |
| Number of Listed Products | at least 20 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Based on known information, rifampicin is a broad-spectrum antibiotic that inhibits bacterial RNA polymerase. Its efficacy in tuberculosis is well established, and it is active against Gram-positive bacteria, Chlamydia and Staphylococcus.
These organisms are common causes of bacterial conjunctivitis and trachoma, so an antibacterial link to conjunctivitis is plausible. Older studies tested rifampicin eye ointment in chlamydial eye infections. A 1977 open trial of 1% rifampicin ointment in chlamydial eye infection found that 3 weeks was not enough to cure the disease, while a 6–7 week course gave about 90% clinical and microbiological cure. A 1975 controlled trial in Tunisia compared topical tetracycline and rifampicin in endemic trachoma.
However, the evidence is indirect. Well-established first-line topical antibiotics are available for conjunctivitis, and using a key anti-TB drug for a common, often self-limiting eye infection risks selecting resistance in TB-endemic settings. The data compiled for this report also contain duplicate conjunctivitis entries (“conjunctivitis”, “conjunctivitis (disease)”, “acute contagious conjunctivitis”) that should be merged during curation.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 1096630 | 1975 | Clinical study | Am J Ophthalmol | Controlled trial in Tunisian schoolchildren with trachoma: 1% tetracycline or 1% rifampicin ointment vs boric acid ointment, twice daily for 10 weeks |
| 322700 | 1977 | Open trial | Br J Ophthalmol | 1% rifampicin vs chloramphenicol ointment in chlamydial eye infection (63 patients); 3 weeks insufficient, 6–7 weeks gave about 90% cure |
| 5005929 | 1971 | Review | Ann Ophthalmol | General review of rifampicin (no abstract available) |
| 33457332 | 2020 | Susceptibility survey | Adv Biomed Res | Bacterial causes and antibiotic susceptibility of conjunctivitis isolates in Kashan, Iran |
| 8363150 | 1993 | Microbiology study | An Esp Pediatr | Neonatal conjunctivitis: 84% of samples culture-positive, mostly staphylococci and streptococci; high sensitivity to most drugs tested |
| 21191558 | 2010 | In vitro study | Rev Esp Quimioter | Antibiotic susceptibility of Corynebacterium macginleyi strains causing conjunctivitis |
| 30347565 | 2018 | Genotyping/susceptibility study | Zhonghua Yan Ke Za Zhi | Genotyping and susceptibility of S. aureus from keratitis or conjunctivitis |
| 3191080 | 1988 | Case report | Br J Ophthalmol | Marginal corneal abscess in adult chlamydial ophthalmia |
| 39336466 | 2024 | Case report | Medicina (Kaunas) | Parinaud oculoglandular syndrome with Bartonella DNA in cornea and conjunctiva |
| 1247775 | 1976 | Report | Br Med J | Ocular toxicity due to rifampicin |
India Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 184977 | Risorine Capsule | Strip of 10 capsules | Not stated |
| 186328 | Rifamycin 450mg Tablet | Strip of 10 tablets | Not stated |
| 78081 | Eufacin Inh 450 mg/300 mg Tablet | Strip of 10 tablets | Not stated |
| 193271 | Rimpin 450mg Capsule | Strip of 10 capsules | Not stated |
| 143426 | Monocin 500mg Injection | Vial of 2 ml injection | Not stated |
All 20 registrations are valid single-ingredient licences; only five are listed here. The data compiled for this report include oral and injectable forms, and none of the listed registrations is an ophthalmic preparation.
Cytotoxicity
Not applicable. This section is omitted because rifampicin is an antibacterial, not an antineoplastic drug.
Safety Considerations
- Contraindications flagged by the knowledge graph (not label text): liver failure and liver disease, hepatitis, porphyria, thrombocytopenia, neutropenia, agranulocytosis, aplastic anaemia and pancytopenia, peripheral neuropathy, diabetes (including diabetic ketoacidosis), gout, gallbladder disease, substance abuse/dependence, and slow acetylator status.
- Drug Interactions: 256 interactions were recorded. The first 20 reviewed are all moderate, including rabeprazole, omeprazole, doxycycline, metformin, pioglitazone, bupropion, aprepitant, morphine, clarithromycin, metronidazole, and several corticosteroids and vitamin D analogues. Rifampicin is a strong CYP and P-gp inducer, which can lower exposure to many co-medications, notably antiretrovirals and hormonal contraceptives.
- Ocular safety: reports of ocular toxicity due to rifampicin exist in the literature (1976).
Please refer to the package insert for full warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The antibacterial rationale is plausible and some older topical studies exist, but there are no registered trials, and the supporting literature is indirect and dated. Established topical antibiotics are available, and use of rifampicin risks resistance selection in TB-endemic settings. The model score alone does not justify advancing.
To proceed, the following is needed:
- Package insert warnings and contraindications (not available in the data compiled for this report, so safety screening cannot proceed)
- Detailed mechanism of action data
- Merging of the duplicate conjunctivitis entries and clarification of the target pathogens (e.g., chlamydial or staphylococcal conjunctivitis)
- A specific ophthalmic formulation and route strategy, since no ophthalmic product is registered in India
- Comparative evidence against current first-line topical antibiotics and a resistance-risk assessment
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.