The length of a treatment for a basic vaginal yeast infection depends on the type of treatment the patient selects, according to Everyday Health. Diflucan, a powerful oral medication, only requires one dose, while topical treatment lengths range from one to seven days.
If a patient is dealing with a complicated yeast infection, the treatment type and length varies, reports Everyday Health. In these cases, doctors often prescribe extended treatments, such as a seven- to 14-day course of an azole medication or up to three days of an oral medication. To keep yeast infections from recurring, a doctor can prescribe oral azole tablets for as long as six months.