The present disclosure provides for methods of treating a patient with a CYP3A4 substrate drug, wherein the patient is treated with posaconazole. In some embodiments, the patient stops posaconazole treatment, waits for at least 2 days, and then is treated with the CYP3A4 substrate drug as soon as it is safe to do so. In some embodiments, treatment with the CYP3A4 substrate drug is delayed for about 2-42 days after stopping posaconazole. In some embodiments, the patient is treated with a reduced dose of the CYP3A4 substrate drug for about 2-42 days.