Here are the facts
Most cases of onychomycosis(nail fungus) is caused by the fungi T. Rubrum or T. Mentagrophytes.However, a nail culture should be taken to confirm the diagnoses.One of the reasons that treatments for nail fungus fail is that not all fungi respond to the oral treatments in the same way.Make sure to tell you doctor what medications you are taking as the antifungals may interact with them rendering them ineffective.
There are many treatments for Mycotic nails(nail fungus).Topical treatments only work in very mild cases of onychomycosis(nail fungus) and are used primarily for children .Oral medications like Lamisil and Sporonox work in most cases but you have to have blood tests to make sure the medication is not affecting your liver.
For those patients who are on other medications,or who have liver problems there is a newer laser therapy.
The doctor applies a small laser to each nail and kills the fungus.The laser is not 100% effective and it is not covered by insurance.