The fungal infection on your heels is likely a form of athlete's foot, a relatively common and very treatable condition, and your doctor will probably prescribe a topical antifungal medication for you to apply directly to the affected skin. Clotrimazole, miconazole nitrate, terbinafine hydrochloride, ciclopirox, econazole, ketoconazole and oxiconazole are among the common prescription antifungal medicines used to cure athlete's foot. The specific product your doctor prescribes will depend on the exact location and extent of your infection. In serious cases, you may need more powerful antifungal medicines that are ingested orally. These medications may have significant side effects. Discuss the advantages and disadvantages of all available prescription medicines with your doctor prior to commencing use.