Usual Adult Dose for Schizophrenia

Initial dose: 1 mg orally twice a day
Maintenance dose: 6 to 12 mg twice a day
Maximum dose: 24 mg/day

Comments:

• This drug must be titrated slowly to avoid orthostatic hypotension.
• Control of symptoms may be delayed during the first 1 to 2 weeks of treatment because of the need to titrate slowly.
• Treatment should be increased in increments of not more than 2 mg twice daily as tolerated.
• Healthcare providers should periodically re-evaluate the long-term risks and benefits of the drug for the individual patient.

Renal Dose Adjustments

No adjustment recommended.

Liver Dose Adjustments

Mild liver dysfunction: No adjustment recommended.
Moderate liver dysfunction: Dosage adjustment(s) may be required; however, no specific guidelines have been suggested. Caution recommended.
Severe liver dysfunction: Not recommended.

Dose Adjustments

CYP450 2D6 poor metabolizers:

• Reduce the dose by one-half.

• Reduce the dose by one-half when administered with strong CYP450 2D6 inhibitors (e.g., fluoxetine, paroxetine) or strong CYP450 3A4 inhibitors (e.g., ketoconazole, clarithromycin).
• When the inhibitor is stopped, the dose may be increased to where it was before.

Precautions

US BOXED WARNINGS:
INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS

• Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death.
• This drug is not approved for use in patients with dementia-related psychosis.

Dialysis

Data not available

Other Comments

Administration Advice:

• This drug may be taken with or without food.

• Protect from light and moisture.

• Prior to starting treatment, healthcare providers should take into account need for dose titration and therefore delay in symptom control, and QT interval prolongation risk.
• For patients reinitiating treatment after an off interval of more than 3 days, the initial titration schedule should be followed.
• Controlled clinical trials have shown a delay in time to relapse in patients with schizophrenia.
• No specific recommendations are available regarding switching from other antipsychotics or for the use of concomitant antipsychotics.

• Cardiovascular: Orthostatic vital signs in at-risk patients
• Hematologic: CBC frequently during the first few months in patients with preexisting low WBC and/or a prior history of drug-induced leukopenia or neutropenia.
• Metabolic: Increases in blood sugar, weight, and lipids

• Inform patients that this drug may cause dizziness upon arising; tell patients that it is best to get up slowly form a seated or lying position.
• This drug may impair judgment, thinking, or motor skills; patients should be told to avoid driving or operating machinery until adverse effects are determined.
• Advise patients to speak to their health care provider if they are pregnant, intend to become pregnant, or are breastfeeding.
• Advise patients that this drug may cause metabolic changes (e.g., increases in blood sugar, body weight and lipids).
• Patients should avoid overheating and dehydration.