Dapsone
| Evidence Level: L1 | Predicted Indications: 1 |
Table of Contents
- Dapsone
- Pharmacist Assessment Report
- Dapsone: sulfone antibacterial (dihydropteroate synthase inhibitor) → pneumocystosis (pneumocystosis)
- One-Sentence Summary
- Quick Overview
- Why is This Prediction Reasonable?
- Clinical Trial Evidence
- Literature Evidence
- Australia Market Information
- Safety Considerations
- Conclusion and Next Steps
- Disclaimer
Dapsone: sulfone antibacterial (dihydropteroate synthase inhibitor) → pneumocystosis (pneumocystosis)
Note: the page language is English, so the main prediction’s name is written once without parentheses in the text below; the H1 follows the required format using the single English name.
One-Sentence Summary
Dapsone is a sulfone antibacterial and anti-inflammatory medicine. The TxGNN model predicts it may be effective for pneumocystosis, with 10 clinical trials and 20 publications compiled for this report, including several completed Phase 3 trials that directly study Pneumocystis pneumonia (PCP) prevention and treatment.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not recorded in the local data |
| Predicted New Indication | pneumocystosis |
| TxGNN Prediction Score | 0.9973 |
| Evidence Level | L1 |
| Australia Market Status | Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data |
| Number of PBS Items | 1 (valid: 1) |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data were not available in the data compiled for this report. Based on the known pharmacology of the sulfone class, dapsone inhibits dihydropteroate synthase in the folate synthesis pathway. This is the same target as sulfonamides such as trimethoprim-sulfamethoxazole (TMP-SMX).
Pneumocystis jirovecii depends on this folate pathway, so the mechanism is plausible. Dapsone is already described in the literature as a second-line agent for PCP prophylaxis, particularly for people who cannot tolerate TMP-SMX. It is also used with trimethoprim for mild-to-moderate PCP treatment. The compiled reviews and network meta-analyses describe dapsone-based regimens as established alternatives.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrolment | Key Findings |
|---|---|---|---|---|
| NCT00000991 | Phase 3 | Completed | 600 | Three anti-Pneumocystis regimens (including dapsone) plus zidovudine for primary prevention in advanced HIV |
| NCT00000802 | Phase 3 | Completed | 700 | Daily dapsone vs daily atovaquone for PCP prophylaxis in people intolerant of trimethoprim/sulfonamides |
| NCT00001028 | Phase 3 | Completed | 400 | Monthly aerosolised pentamidine vs thrice-weekly dapsone for PCP prophylaxis |
| NCT00000640 | Phase 3 | Completed | 290 | Dapsone/trimethoprim and clindamycin/primaquine vs TMP-SMX for mild-to-moderate PCP |
| NCT00000739 | Phase 1 | Completed | 96 | Daily vs weekly dapsone dosing for PCP prophylaxis in HIV-infected children |
| NCT00002120 | Phase 1 | Completed | 20 | Trimetrexate with leucovorin plus dapsone vs TMP-SMX for moderately severe PCP |
| NCT00002043 | NA | Completed | Not reported | Dapsone 100 mg vs 50 mg for primary PCP prophylaxis in AIDS-related complex |
| NCT00002283 | NA | Completed | Not reported | Dapsone plus trimethoprim vs TMP-SMX for first-episode PCP in AIDS |
| NCT02550080 | Phase 4 | Unknown | 3130 | HLA-B*1301 genetic screening to reduce dapsone hypersensitivity syndrome (safety study; not an efficacy trial) |
| NCT00636935 | Phase 4 | Withdrawn | 0 | Corticosteroids and fibrosis in PCP (not about dapsone efficacy) |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 38583518 | 2024 | Meta-analysis | Clin Microbiol Infect | Network meta-analysis of RCTs comparing PCP prophylaxis regimens (TMP-SMX, dapsone-based, aerosolised pentamidine, atovaquone) in people living with HIV |
| 39732393 | 2025 | Meta-analysis | Clin Microbiol Infect | Network meta-analysis of RCTs of PCP treatment regimens in people living with HIV |
| 27550992 | 2016 | Guideline | J Antimicrob Chemother | ECIL guidelines for PCP prevention in haematological malignancy and stem cell transplant; TMP-SMX is the drug of choice |
| 33870843 | 2021 | Review | Expert Opin Pharmacother | Review of P. jirovecii with a focus on prevention and treatment |
| 11155588 | 2001 | Review | Dermatol Clin | Dapsone and sulfapyridine; dapsone is useful for PCP prophylaxis in HIV disease |
| 18971152 | 2008 | Review | J Formos Med Assoc | Overview of Pneumocystis pneumonia |
| 9227859 | 1997 | Review | Clin Microbiol Rev | Extrapulmonary pneumocystosis |
| 1727534 | 1992 | Review | Med Clin North Am | Pneumocystosis is largely preventable and treatable |
| 33280223 | 2021 | Retrospective review | Pediatr Transplant | Methemoglobinemia with dapsone PJP prophylaxis in paediatric kidney transplant recipients |
| 9606476 | 1998 | Case report | Ann Pharmacother | Dapsone-induced methemoglobinemia during PCP prophylaxis |
Australia Market Information
| ARTG Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| ARTG 1272Y | DAPSOMED | Tablet 100 mg | Not recorded in the local data |
Safety Considerations
- Conditions of concern (from reference relation data, not label text): liver disease, gallbladder disease, anaemia (including macrocytic anaemia), G6PD deficiency, glycogen storage disease, cystinuria, galactosaemia, pyruvate dehydrogenase E3 deficiency, and methaemoglobinaemia due to methaemoglobin reductase deficiency.
- Drug Interactions: 100 potential interactions were identified. The main moderate-level ones include aprepitant, metronidazole, picosulfuric acid, nateglinide, nitisinone, rosuvastatin, simvastatin, tinidazole, activated charcoal and troglitazone.
- Reported adverse effects in the literature: methaemoglobinaemia and hypoxia, hepatic complications, acute pancreatitis, and dapsone hypersensitivity syndrome (HLA-B*1301 association).
Please also refer to the TGA-approved Product Information (PI) for full safety information.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: Several completed Phase 3 trials directly compare dapsone-containing regimens for PCP prevention and treatment, supported by recent network meta-analyses. The Australian label indication is not recorded in the local data, and the safety profile requires active management.
To proceed, the following is needed:
- Confirm the TGA-approved indications and PI safety text for DAPSOMED (ARTG 1272Y)
- G6PD deficiency screening before use, with monitoring for methaemoglobinaemia and haemolysis
- Caution in patients with sulfonamide hypersensitivity (possible cross-reactivity), and consideration of HLA-B*1301 screening where appropriate
- Mechanism-of-action data to be formally documented
- Review of interacting medicines in each patient’s regimen
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.