A cost analysis of topical drug regimens for dermatophyte infections.

OBJECTIVE To examine the extra cost of using higher-priced drugs as initial therapy for dermatophyte infections, because the many available effective drugs vary considerably in cost. DESIGN Cost analysis from the purchaser's perspective, comparing two prototypical regimens to treat tinea pedis: one in which all patients initially receive a lower-priced drug and those with unresponsive infections receive a higher-priced drug at a follow-up office visit, and one in which all patients receive the higher-priced drug from the outset. The reference drug was miconazole, an imidazole available without a prescription, for which reported overall efficacy rates are 70% to 100%. MAIN OUTCOME MEASURES The threshold efficacy rate (the efficacy rate of miconazole below which it is always less expensive to use a specific higher-priced drug first) and the extra cost (of beginning therapy with a higher-priced drug). RESULTS Assuming the Medicare-approved charge for a follow-up visit ($21.98), it is less expensive to begin therapy with a prescription drug only if the efficacy rate of miconazole is less than 55%; this threshold efficacy rate varied from 26% (for a $0 total cost of the follow-up visit) to 79% (for an $89 total cost of the follow-up visit). If the efficacy rate of miconazole is 70%, the extra cost per patient for all patients to receive the least expensive prescription antifungal drug instead of miconazole first was $15.23 and $8.64 if total visit costs were $0 and $21.98; miconazole remained the less expensive alternative as long as the total cost of the follow-up visit was less than $50.76. CONCLUSION For reported efficacy rates and standard costs of a follow-up office visit, using miconazole first and then treating only those patients with unresponsive infections with a higher-priced prescription drug is less expensive than treating all patients with the higher-priced drug.