Effect of Different Itraconazole Dosing Regimens on Cure Rates, Treatment Duration, Safety, and Relapse Rates in Adult Patients With Tinea Corporis/Cruris

Abstract

With worldwide emergence of recalcitrant and resistant dermatophytosis, itraconazole is increasingly being used as the first-line drug for treatment of tinea corporis/cruris (TCC). Apparent inadequacy with low doses has led to empirical use of higher doses and antifungal combinations. To compare cure rates, treatment durations, safety profiles, and relapse rates of itraconazole 100, 200, and 400 mg/d for the treatment of TCC. This double-blind randomized clinical trial included adult patients with treatment-naive TCC involving at least 5% body surface area. Patients were recruited from the dermatology outpatient department of a tertiary care hospital in New Delhi, India between March 1, 2020, and August 31, 2021. Patients were randomized to 1 of the 3 treatment groups. Biweekly blinded assessments were performed until cure or treatment failure. Posttreatment follow-up of at least 8 weeks was conducted to detect relapses. Cure rates, treatment durations, safety profiles, and relapse rates were assessed. Secondary outcomes included comparison of rapidity of clinical response and cost-effectiveness between groups. Of the 149 patients assessed, the mean (SD) age was 34.3 (12.2) years, 69 patients (46.4%) were women, and 80 patients (53.6%) were men. The difference in cure rate between the 100- and 200-mg groups was statistically nonsignificant (hazard ratio [HR], 1.44; 95% CI, 0.91-2.30; P = .12), while the difference between the 100- and 400-mg groups (HR, 2.87; 95% CI, 1.78-4.62; P < .001) and between the 200- and 400-mg groups (HR, 1.99; 95% CI, 1.28-3.09; P = .002) was statistically significant. Mean (SD) treatment durations were statistically significantly different between the 100- and 400-mg groups (7.7 [4.7] weeks vs 5.2 [2.6] weeks; P = .03) and between the 200- and 400-mg groups (7.2 [3.8] weeks vs 5.2 [2.6] weeks; P = .004), but the difference between the 100- and 200-mg groups was not statistically significant. A total of 55 patients (47.4%) relapsed after treatment. Relapse rates were comparable across groups. No patient discontinued treatment due to adverse effects. Treatment with the 200-mg dose incurred a 63% higher cost and 400 mg a 120% higher cost over 100 mg in achieving cure. In this randomized clinical trial, high overall efficacy was observed among the 3 itraconazole doses for treatment of TCC, but with prolonged treatment durations and considerable relapse rates. Treatment with the 200- and 100-mg doses did not differ significantly in efficacy or treatment durations, while 400 mg scored over the other 2 on these outcomes. Considerable additional cost is incurred in achieving cure with the 200- and 400-mg doses. Clinical Trials Registry of India Identifier: CTRI/2020/03/024326.