Original GlobalRPh source
- Product / population
- Preserved GlobalRPh source, not a freshly verified product label
- Renal measure
- Use the method specified in the original source
Historical source: not automatically current. Review current official labeling and separately attributed additions before use.
Historical dose ceilings and approved-use descriptions are preserved, not asserted to be current FDA labeling.
Mechanism and historical indication context
The mechanism is unknown; central dopamine D2 and serotonin 5-HT2A antagonism is proposed. The source describes adult schizophrenia efficacy in four 6-week studies and states that efficacy beyond 6 weeks had not been established in that labeling context. Reevaluate patients receiving extended treatment.
Usual Dosing (Adults)
Start 40 mg once daily without initial titration. The historical source reports effectiveness from 40-120 mg/day, no additional benefit at 120 mg with more adverse reactions, and a maximum recommended dose of 80 mg/day. Take with food of at least 350 calories.
Renal and hepatic dosing
CrCl at least 10 but below 50 mL/min: maximum 40 mg/day in this historical source. After a single 40 mg dose, Cmax increased 40%, 92% and 54% in mild, moderate and severe impairment; AUC increased 53%, 91% and approximately 2-fold respectively.
Moderate/severe hepatic impairment: source maximum 40 mg/day.
Interaction comments
With a moderate CYP3A4 inhibitor such as diltiazem: source maximum 40 mg/day. Do not use with a strong CYP3A4 inhibitor such as ketoconazole or a strong inducer such as rifampin.
Hemodialysis
No additional hemodialysis recommendation was present under this heading in the retrieved source.