The Mayo Clinic lists terbinafine (Lamisil) and itraconazole (Sporanox) as effective oral antifungal drugs for toenail fungus. Both of these medications are available by prescription.
The Mayo Clinic reports that oral antifungal prescription drugs are necessary when over-the-counter treatments have not improved the ailment. However, oral prescription drugs are more effective when used in conjunction with topical over-the-counter treatments. These effects are lessened for adults over age 65. People with certain medical conditions may not be able to take oral antifungal medications. Under these circumstances the Mayo Clinic suggests that ciclopirox (Penlac), an anti-fungal nail polish, is a viable alternative.