Fanapt Dosage

Recommended Dosage

​Titrate FANAPT to avoid orthostatic hypotension.

​Administer FANAPT orally with or without food.

​Table 1 includes dosage recommendations for FANAPT for the treatment of schizophrenia and the acute treatment of manic or mixed episodes associated with bipolar I disorder in adults.

Table 1: Dosage Recommendations for FANAPT in Adults for the Treatment of Schizophrenia or
Acute Treatment of Manic or Mixed Episodes Associated with Bipolar I Disorder

Dosage Recommendations for Use in Patients Who Are Known CYP2D6 Poor Metabolizers

​Reduce the dose of FANAPT by one-half for CYP2D6 poor metabolizers. Table 2 includes dosage recommendations for FANAPT in adults who are CYP2D6 poor metabolizers.

Table 2: Dosage Recommendations for FANAPT in Adults with Schizophrenia or Bipolar I Disorder
Who are CYP2D6 Poor Metabolizers

Dosage Recommendations in Patients with Hepatic Impairment

​No dose adjustment for FANAPT is needed in patients with mild hepatic impairment. Patients with moderate hepatic impairment may require dose reduction, if clinically indicated. FANAPT is not recommended for patients with severe hepatic impairment.

Dosage Modifications for Concomitant Use with Strong CYP2D6 Inhibitors and Strong CYP3A4 Inhibitors

Coadministration with Strong CYP2D6 Inhibitors

Reduce the dose of FANAPT one-half when administered concomitantly with strong CYP2D6 inhibitors such as fluoxetine or paroxetine. When the CYP2D6 inhibitor is withdrawn from the combination therapy, increase the dose of FANAPT to where it was before.

Coadministration with Strong CYP3A4 Inhibitors

Reduce the dose of FANAPT by one-half when administered concomitantly with strong CYP3A4 inhibitors such as ketoconazole or clarithromycin. When the CYP3A4 inhibitor is withdrawn from the combination therapy, increase the dose of FANAPT to where it was before.

Coadministration with Strong CYP2D6 and Strong CYP3A4 Inhibitors

​Reduce the dose of FANAPT by about one-half if administered concomitantly with inhibitors of CYP2D6 and CYP3A4. When both CYP2D6 and CYP3A4 inhibitors are withdrawn from the combination therapy, increase the dose of FANAPT to where it was before.

Reinitiation of Treatment in Patients Previously Discontinued

Although there are no data to specifically address reinitiation of treatment, it is recommended that the initiation titration schedule be followed whenever patients have had an interval off FANAPT of more than 3 days.