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 microg/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.