BACKGROUND:After the introduction of the multidrug therapy, there was a decline in the coefficients of prevalence and detection of new cases of leprosy. However, the records of drug resistance and relapses are threatening factors in leprosy control. Hence, new alternative schemes and monitoring of adverse effects to avoid treatment abandonment are important considerations. OBJECTIVE:Describe the side effects of a multidrug regimen containing minocycline, ofloxacin, and clofazimine in multibacillary leprosy patients.METHODS:We conducted a prospective, descriptive, and observational study with multibacillary patients, including cases of intolerance to standard MDT and relapses. The study was carried out at Fundação Alfredo da Matta (Alfredo da Matta Foundation), in Manaus, Amazonas, from April 2010 to January 2012. The patients received alternative therapy, which consisted of daily self-administered doses of 100mg of minocycline, 400 mg of ofloxacin, and 50mg of clofazimine and a supervised monthly dose of 300mg of clofazimine for six months, followed by eighteen months of daily doses of ofloxacin 400mg, clofazimine 50mg, and a supervised monthly dose of clofazimine 300mg. Results: Twenty-one cases were included. Mild and transitory side effects occurred in 33.3% of patients. Of the total episodes, 45.9% were attributed to ofloxacin and they included abdominal pain, nausea, vomiting, headache, and insomnia; 21.6% were due to clofazimine, with 100% of patients presenting skin pigmentation. The mean time for the development of adverse effects after beginning the therapy was 15.2 days. CONCLUSION:All patients tolerated the drugs well, and compliance was satisfactory, with no serious events. Unlike other standard MDT studies had shown, no treatment was stopped due to side effects. Nevertheless, patient follow-up and studies with bigger samples are necessary to guarantee the efficacy and safety of the alternative regimen as a second-line scheme in multi-drug therapy.