Yes, combining oral terbinafine and topical sertaconazole is a safe, standard, and highly effective treatment for fungal infections on the legs. The oral medication fights the infection from within, while the cream targets it directly on the skin. Typically, this combination is used for 2 to 4 weeks, depending on the severity of your infection. It is very important to complete the entire course prescribed by your doctor, even if your symptoms clear up sooner, to ensure the fungus is fully eradicated and does not return.