What is the dosage for nefazodone?

The recommended dose range is 150-300 mg twice daily. The maximum dose is 600 mg daily. The starting dose is 100 mg twice daily. Doses may be increased weekly by 100 to 200 mg day in two divided doses. As with all antidepressants, the full effect may take a few weeks to become manifest. Doses are often adjusted slowly upward to find the optimal dose. Elderly patients and debilitated persons may need lower doses.

Which drugs or supplements interact with nefazodone?

All antidepressants whose actions include increasing brain concentrations of serotonin, including nefazodone, should not be taken with any of the MAO (monoamine oxidase) inhibitor class of antidepressants, for example, isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), procarbazine (Matulane), and selegiline (Eldepryl). Such combinations may lead to confusion, high blood pressure, tremor, and increased activity. If a patient is switched from nefazodone to an MAO inhibitor, at least one week should be allowed after stopping nefazodone before starting the MAO inhibitor. Two weeks should be allowed between stopping an MAO inhibitor and initiating treatment with nefazodone.

Nefazodone may increase the blood concentration of several drugs by reducing their removal by the liver. Through this mechanism nefazodone may markedly increase the blood concentrations of triazolam (Halcion) and alprazolam (Xanax), resulting in excessive sedation and impaired ability to perform tasks. It is recommended that people taking triazolam who need to be started on nefazodone should have their triazolam dose reduced by 75%. Similarly, those people taking alprazolam who need to take nefazodone should have their alprazolam dose reduced by 50%. Nefazodone also may increase the blood concentration and possibly the side effects of eletriptan (Relpax), eplerenone (Inspra), pimozide (Orap), ranolazine (Ranexa), and silodosin (Rapaflo).

Carbamazepine (Tegretol, Tegretol XR, Equetro, Carbatrol) may decrease nefazodone blood levels and possibly its effectiveness by increasing nefadone’s removal by the liver. Conversely, nefazodone may increase the levels of carbamazepine, possibly leading to toxicity, by decreasing the removal of carbamazepine by the liver.