Multidrug Therapy for Leprosy
Yes, multidrug therapy (MDT) is the standard treatment for leprosy, consisting of rifampin, clofazimine, and dapsone for multibacillary disease, or rifampin and dapsone for paucibacillary disease. 1, 2, 3
Standard MDT Regimens
The World Health Organization established MDT as the cornerstone of leprosy treatment in 1982, representing the most significant advance in leprosy management since the introduction of sulphone drugs. 4, 5
Multibacillary Leprosy (MB)
The recommended regimen consists of three drugs administered for 12 months: 1, 2, 3
- Rifampin: 600 mg monthly (supervised dose) 1, 2
- Clofazimine: 300 mg monthly (supervised) plus 50 mg daily (unsupervised) 1, 2
- Dapsone: 100 mg daily (unsupervised) 1, 6
Paucibacillary Leprosy (PB)
The regimen uses two drugs for 6 months: 5, 7
- Rifampin: 600 mg monthly (supervised)
- Dapsone: 100 mg daily
Critical Pre-Treatment Screening
Before initiating MDT, mandatory screening must be performed to prevent serious adverse events: 1, 2, 3
- G6PD deficiency testing is required before dapsone due to risk of hemolytic anemia and methemoglobinemia 1, 2, 3
- Baseline ECG is necessary before clofazimine to assess QT interval, as the drug can cause QT prolongation 1, 2, 3
Monitoring During Treatment
Regular laboratory monitoring is essential throughout the treatment course: 1, 2
- Complete blood count and liver function tests should be monitored regularly during dapsone therapy 1, 2
- ECG monitoring for QT interval at 2 weeks and when adding any QT-prolonging medications with clofazimine 2
- Clinical response assessment should occur at regular intervals, with lesion flattening expected by 4-6 weeks after treatment initiation 1, 2
Treatment Continuation Principles
MDT should not be interrupted for skin complications or wound healing. 1, 3 This is a critical principle that distinguishes leprosy treatment from many other infectious diseases. Treatment must continue even when complications arise, as premature discontinuation worsens outcomes. 1, 3
Managing Leprosy Reactions
Leprosy reactions must be distinguished from treatment failure—they require anti-inflammatory management while continuing MDT: 1, 2, 3
- Type 1 reversal reactions should be treated with corticosteroids while continuing MDT 1, 3
- Type 2 reactions (erythema nodosum leprosum) also require anti-inflammatory therapy without stopping MDT 2, 3
This distinction is crucial because reactions represent immunologic phenomena rather than treatment failure, and stopping MDT during reactions leads to worse outcomes. 1, 3
Special Populations
Pregnancy
Treatment should be continued during pregnancy as benefits outweigh risks, with close monitoring required. 2, 3 The risk of untreated leprosy to both mother and fetus exceeds the risks of MDT medications.
Pediatric Patients
Clofazimine has been well-tolerated in pediatric leprosy trials at 1-2 mg/kg/day (maximum 100 mg). 2 Dapsone dosing should be correspondingly reduced in children compared to the adult dose of 100 mg daily. 6
Common Pitfalls and How to Avoid Them
The most critical error is premature treatment discontinuation due to leprosy reactions. 1, 3 Clinicians must recognize that inflammatory reactions during treatment are expected immunologic phenomena, not treatment failure. Continue MDT and add anti-inflammatory therapy rather than stopping antibiotics.
Inadequate pre-treatment screening leads to preventable serious adverse events: 1, 2, 3
- Failure to screen for G6PD deficiency before dapsone can result in life-threatening hemolytic anemia
- Omitting baseline ECG before clofazimine may miss patients at risk for dangerous QT prolongation
Patient counseling about clofazimine-related skin pigmentation is essential. 4, 8 Pink to brownish-black discoloration occurs in 75-100% of patients within 1-4 weeks but resolves 6-12 months after stopping the drug. 2 Light-skinned patients may be particularly concerned about this visible side effect, which can lead to non-adherence if not properly explained beforehand. 4
Efficacy and Resistance
MDT has proven remarkably effective with few toxic side-effects, contributing to a dramatic decline in global leprosy cases from 5.37 million in 1985 to 3.1 million by 1992. 4 The combination approach prevents the development of secondary dapsone resistance that occurred with historical monotherapy. 6, 4, 9
If dapsone resistance is suspected (clinical and bacteriological relapse despite regular supervised therapy for 3-6 months), alternative drugs should be considered. 6 Newer agents including fluoroquinolones (ofloxacin, pefloxacin), minocycline, and clarithromycin are available as second-line options. 4, 9