perphenazine 16 mg tablet

Dosage and Administration

Administration

Perphenazine is administered orally. Perphenazine oral solution is intended for use only in hospitalized patients. When the oral concentrate solution is used, the dose should be diluted (e.g., with water, Seven-Up, sodium chloride solution, or milk, or with pineapple, apricot, prune, orange, tomato, V-8, or grapefruit juice) just before administration. (See Chemistry and Stability: Stability.) For optimum palatability, the manufacturer suggests that at least 60 mL of diluent be used for each 16 mg (5 mL) of concentrate administered.

Dosage

Dosage of perphenazine must be carefully adjusted according to individual requirements and response, using the lowest possible effective dosage. Dosage should be increased more gradually in debilitated or geriatric patients. Because of the risk of adverse reactions associated with cumulative effects of phenothiazines, patients with a history of long-term therapy with perphenazine and/or other antipsychotic agents should be evaluated periodically to determine whether maintenance dosage could be decreased or drug therapy discontinued.

Prolonged administration of perphenazine dosages exceeding 24 mg daily should be limited to hospitalized patients or patients under continued observation for early detection and management of adverse reactions. An antiparkinsonian agent, such as trihexyphenidyl or benztropine, is valuable in controlling drug-induced extrapyramidal reactions.

Schizophrenia

For the symptomatic management of schizophrenia in moderately disturbed outpatients, the usual initial oral dosage of perphenazine in adults and children older than 12 years of age is 4-8 mg 3 times daily. Subsequent dosage of perphenazine should be reduced to the lowest possible effective dosage as soon as possible. For the symptomatic management of schizophrenia in hospitalized adults and children older than 12 years of age, the usual initial oral dosage of perphenazine is 8-16 mg 2-4 times daily. Oral dosage of perphenazine in adults should not exceed 64 mg daily. Dosage for children younger than 12 years of age has not been established.

Severe Nausea and Vomiting

For the control of severe nausea and vomiting in adults, the usual initial oral dosage of perphenazine is 8-16 mg daily in divided doses. Occasionally, dosages up to 24 mg daily may be required in some patients, but subsequent dosage should be reduced as soon as possible.

Dosage in Geriatric Patients

Although geriatric dosages of perphenazine preparations have not been established, plasma concentrations of perphenazine per daily ingested dose appear to increase with increasing patient age. In general, dosage selection for geriatric patients should be cautious, usually starting at the low end of the dosage range, and reflect the greater frequency of decreased hepatic function and concomitant disease or drug therapy observed in geriatric individuals. Geriatric patients are particularly sensitive to certain adverse effects of perphenazine (e.g., sedation, orthostatic hypotension), which potentially may result in injuries (e.g., falls, hip fractures). Perphenazine may be administered before bedtime as needed. Administration of lower dosages for longer periods of time may be required to achieve optimal therapeutic results in this patient population. For information on the use of antipsychotic agents for dementia-associated psychosis, and