Equivalent therapeutic efficacy and safety of ivermectin and lindane in the treatment of human scabies

Objective: To compare the therapeutic efficacy and safety of ivermectin and lindane for the treatment of human scabies. Design: Randomized, prospective, controlled, double-blind, "double-dummy," and parallel clinical study. Setting: A single department of dermatology at a hospital in Buenos Aires, Argentina. Patients: Patients were outpatients, hospitalized patients, and those referred to our hospital from nursing homes and asylums. Fifty-three patients had clinical signs and symptoms compatible with scabies. Intervention: Patients received either a single oral dose of ivermectin (150-200 mu g/kg of body weight) or a topical application of 1% lindane solution. Treatment was repeated after 15 days if clinical cure had not occurred. Main Outcome Measures: Clinical healing and adverse effects. Results: Of 53 patients, 43 (81%) completed the study, 19 in the group treated with ivermectin and 24 in the group treated with lindane. At day 15, 14 patients (74%; 95%;, confidence interval, 48.8%-90.8%) in the group receiving ivermectin showed healing of their scabies and 13 patients (54%; 95% confidence interval, 32.8%-74.4%) in the group treated with lindane were healed. At 29 days, both treatments resulted in statistically equivalent therapeutic efficacy: 18 patients (95%; 95% confidence interval, 74.0%-99.9%) were healed with ivermectin and 23 patients (96%; 95% confidence interval, 78.9%, 99.9%) were healed with lindane (P<.02). Adverse effects from the treatments were few, mild; and transient. Results from laboratory tests showed no major abnormalities and no difference between treatments. Conclusions: Ivermectin is as effective as lindane for the treatment of scabies. Ivermectin is simpler to use and, therefore, is a promising tool to improve compliance and to control infestations.