Doctors prescribe nystatin, an antifungal mouthwash, for adults who have mild cases of thrush, according to MedicineNet. Commercial over-the-counter mouthwashes sometimes disrupt the balance of the mouth's micro-organisms, so doctors do not typically recommend them for treatment of thrush, Mayo Clinic reports.
Doctors often do not treat infants, toddlers or children who have thrush because the condition clears up on its own, states MedicineNet. If not, doctors sometimes prescribe nystatin drops. People who have severe cases of thrush or impaired immune systems receive systemic drugs, including fluconazole, itraconazole and amphotericin B.
If a nursing mother's baby has thrush, the doctor treats the infant, Mayo Clinic says. In addition, the mother uses a prescription antifungal cream on her breasts to prevent the spread of the fungus.