Prospective study on the relationship between intensive bactericidal therapy and leprosy reactions.

A systematic study was performed on the reactions occurring during several short-course therapy regimens for the treatment of paucibacillary and multibacillary patients. Most type 1 upgrading reactions in paucibacillary (PB) leprosy were mild to moderate and of short duration, while the time of onset was extremely variable. Their incidence was higher in the regimen rifampin (RMP) 900 mg once weekly for ten weeks than when a single dose of RMP 40 mg/kg body weight was given or 1500 mg in one dose followed by one year of dapsone (DDS) 100 mg daily. In multibacillary (MB) leprosy, three regimens were compared: MB-WHO regimen; regimen C, consisting of daily RMP 600 mg, ethionamide (ETH) 500 mg, and DDS or clofazimine (CLO) 100 mg for six months, followed by six months of daily DDS or CLO; and regimen D, identical to regimen C but comprising daily DDS or CLO plus ETH 500 mg during the second semester. Type 1 upgrading reactions occurred more frequently in MB patients and were more severe than in PB patients. They occurred more frequently and were more severe in regimens C and D than in the MB-WHO regimen. CLO 100 mg daily prevented type 1 reactions in MB patients and rendered them less severe. ENL was also more frequent in regimens C and D and was not prevented by CLO in the dosage used. Although there is some correlation between type 1 reactions and the total amount of RMP administered, other aspects of RMP administration.(ABSTRACT TRUNCATED AT 250 WORDS)