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Uses

Pending revision, the material in this section should be considered in light of more recently available information in the MEDWATCH notification at the beginning of this monograph.

Schizophrenia

Symptomatic management of schizophrenia.

Bipolar Disorder

Management (alone or in combination with lithium or divalproex sodium) of acute manic episodes associated with bipolar I disorder.

Dosage and Administration

Administration

Oral Administration

Administer orally, generally 2–3 times daily without regard to meals.

When switching from other antipsychotic agents to quetiapine, abrupt discontinuance of previous agent may be acceptable for some patients with schizophrenia, but gradual discontinuance may be appropriate for others. In all cases, minimize period of overlapping antipsychotic administration.

In patients being switched from long-acting (depot) parenteral antipsychotic therapy to oral quetiapine therapy, administer first oral dose in place of next scheduled depot injection of the long-acting preparation.

Periodically reevaluate need for continuing any existing drug therapy for symptomatic relief of adverse extrapyramidal effects.

Dosage

Pending revision, the material in this section should be considered in light of more recently available information in the MEDWATCH notification at the beginning of this monograph.

Available as quetiapine fumarate; dosage is expressed in terms of quetiapine.

Reinitiating therapy: In patients previously treated with quetiapine, dosage titration is not necessary if reinitiated after a drug-free period <1 week; if reinitiated after a drug-free period >1 week, generally titrate dosage as with initial therapy.

Adults

Pending revision, the material in this section should be considered in light of more recently available information in the MEDWATCH notification at the beginning of this monograph.

Schizophrenia

Oral

Initially, 25 mg twice daily.

Increase dosage in increments of 25–50 mg 2 or 3 times daily on the second or third day, as tolerated, to a target dosage of 300–400 mg daily in 2 or 3 divided doses by the fourth day.

Make subsequent dosage adjustments at intervals of not less than 2 days, usually in increments or decrements of 25–50 mg twice daily.

Dosages ranging from 150–750 mg daily were effective in clinical trials. Dosages >300 mg daily usually do not result in greater efficacy, but dosages of 400–500 mg daily have been required in some patients.

Optimum duration of therapy currently not known, but efficacy of maintenance therapy with antipsychotics is well established. Continue therapy in responsive patients as long as clinically necessary and tolerated but at lowest possible effective dosage; reassess need for continued therapy and optimal dosage periodically (e.g., at least annually).

If discontinuance is considered, precautions include slow, gradual dose reduction over many months, more frequent clinician visits, and use of early intervention strategies.

Bipolar Disorder

Acute Mania

Oral

Initially, 100 mg daily in 2 divided doses. Increase dosage (in increments of ≤100 mg daily in 2 divided doses) to 400 mg daily on the fourth day of therapy. Make subsequent adjustments in increments of ≤200 mg daily to reach a dosage of up to 800 mg daily by the sixth day of therapy.

Majority of patients respond to 400–800 mg daily.

Optimum duration not established; efficacy has been demonstrated in two 12-week monotherapy trials and one 3-week adjunct therapy trial. If used for extended periods, periodically reevaluate long-term risks and benefits for the individual patient.

Prescribing Limits

Adults

Schizophrenia

Oral

Safety of dosages >800 mg daily not established.

Bipolar Disorder

Acute Mania

Oral

Safety of dosages >800 mg daily not established.

Special Populations

Dosage in Hepatic Impairment

Initially, 25 mg daily; increase dosage by 25–50 mg daily according to clinical response and tolerability until an effective dosage is reached.

Dosage in Renal Impairment

No dosage adjustment necessary.

Patients at Risk of Orthostatic Hypotension

Consider a slower rate of dosage titration and a lower target dosage in geriatric patients and in patients who are debilitated or have a predisposition to hypotensive reactions. Adjust dosage with caution.

Initially, 25 mg twice daily to minimize risk of orthostatic hypotension and associated syncope. If hypotension occurs during dosage titration, return to previous dosage in titration schedule.