PERPHENAZINE
(per-fen'a-zeen)
Trilafon
Classifications: central nervous system agent; psychotherapeutic; phenothiazine antipsychotic; antiemetic
Prototype: Chlorpromazine
Pregnancy Category: C
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2 mg, 4 mg, 6 mg, 8 mg, 16 mg, tablets; 16 mg/5 mL liquid; 5 mg/mL injection
Affects all parts of CNS similar to chlorpromazine, particularly the hypothalamus. Antipsychotic effect: Antagonizes the neurotransmitter
dopamine by action on dopamine receptors in the brain. Antiemetic action results from direct blockade of dopamine in the chemoreceptor
trigger zone (CTZ) in the medulla.
Has antipychotic and antiemetic properties. Produces less sedation and hypotension, greater antiemetic effects, higher incidence
of extrapyramidal effects, and lower levels of anticholinergic adverse effects than chlorpromazine.
Psychotic disorders, symptomatic control of severe nausea and vomiting, acute conditions such as violent retching during surgery,
and intractable hiccups.
Hypersensitivity to perphenazine and other phenothiazines; preexisting liver damage; suspected or established subcortical
brain damage, comatose states; bone marrow depression. Safety during pregnancy (category C), lactation, or in children <12
y is not established.
Previously diagnosed breast cancer; liver or kidney dysfunction; cardiovascular disorders; alcohol withdrawal, epilepsy, psychic
depression, patients with suicidal tendency; glaucoma; history of intestinal or GU obstruction; geriatric or debilitated patients;
patients who will be exposed to extremes of heat or cold, or to phosphorous insecticides.
Psychotic Disorders
Adult: PO 4–16 mg b.i.d. to q.i.d.; 8–32 mg sustained release b.i.d. (max: 64 mg/d) IM 5 mg q6h (max: 15–30 mg/d) IV Dilute to 0.5 mg/mL in NS, administer at not more than 1 mg q1–2min or 5 mg by slow infusion
Child: PO 4 mg b.i.d. to q.i.d.; 8 mg sustained release b.i.d. (max:16 mg/d) IM/IV Same as adult
Dementia Behavior
Geriatric: PO 2–4 mg 1–2 times/d, may increase q4–7d (max: 32 mg/d)
Nausea
Adult: PO 8–16 mg b.i.d. to q.i.d. IM 5 mg q6h (max:15 mg/d)
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Oral
- Ensure that sustained release form is not chewed or crushed. Must be swallowed whole.
- Dilute oral concentrate before administration: Dilute each 5 mL (16 mg) to 60 mL water, milk, saline solution, 7-Up, or other
compatible carbonated beverages. Do not use liquids that cause color changes or precipitate.
Intramuscular
- Give deep IM into a large muscle with patient in recumbent position. Advise patient to continue lying down for at least 1
h after injection. Injection may be painful. Observe daily for signs of inflammation.
| Intravenous PREPARE: Direct: Dilute each 5 mg in 9 mL NS.
ADMINISTER: Direct: Give at a rate of 0.5 mg (1 mL) over 60 sec.
INCOMPATIBILITIES Solution/additive:
Midazolam,
pentobarbital,
thiethylperazine.
Y-site:
Cefoperazone,
midazolam,
pentobarbital.
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- Do not use precipitated or darkened parenteral solution; however, slight yellowing does not alter potency or therapeutic effects.
- Protect solutions from light.
CNS:
Extrapyramidal effects (dystonic reactions, akathisia, parkinsonian syndrome, tardive dyskinesia), sedation, convulsions. CV:
Orthostatic hypotension, tachycardia, bradycardia. Special Senses: Mydriasis, blurred vision, corneal and lenticular deposits. GI: Constipation, dry mouth, increased appetite, adynamic ileus, Abnormal liver function tests, cholestatic jaundice. Urogenital:
Urinary retention, gynecomastia, menstrual irregularities, inhibited ejaculation. Hematologic:
Agranulocytosis, thrombocytopenic purpura, aplastic or hemolytic anemia. Body as a Whole: Photosensitivity, itching, erythema, urticaria, angioneurotic edema, drug fever, anaphylactoid reaction, pain at injection site, sterile abscess. Nasal congestion, decreased sweating. Metabolic: Hyperprolactinemia, galactorrhea, weight gain.
Perphenazine may cause falsely abnormal thyroid function tests because of elevations of thyroid globulin.
Drug:
Alcohol and other cns depressants enhance CNS depression; antacids, antidiarrheals may decrease absorption of phenothiazines; anticholinergic agents add to anticholinergic effects including fecal impaction and paralytic ileus; barbiturates, anesthetics increase hypotension and excitation. Herbal:
Kava-kava increased risk and severity of dystonic reactions.
Absorption: Poorly absorbed from GI tract; 20% reaches systemic circulation. Onset: 10 min IM. Peak: 1–2 h IM; 4–8 h PO. Duration: 6–12 h. Distribution: Crosses placenta. Metabolism: Metabolized in liver with some metabolism in GI tract. Elimination: Excreted in urine and feces. Half-Life: 9.5 h.
Assessment & Drug Effects
- Establish baseline BP before initiation of drug therapy and check it at regular intervals, especially during early therapy.
- Monitor BP and pulse continuously during IV administration. Keep patient supine until assured that vital signs are stable.
Observe older adult patients carefully for hypotension and extrapyramidal reactions.
- Report restlessness, weakness of extremities, dystonic reactions (spasms of neck and shoulder muscles, rigidity of back, difficulty
swallowing or talking); motor restlessness (akathisia: inability to be still); and parkinsonian syndrome (tremors, shuffling
gait, drooling, slow speech). A high incidence of extrapyramidal effects accompanies use of perphenazine, particularly with
high doses and parenteral administration.
- Withhold medication and report IMMEDIATELY to physician S&S of irreversible tardive dyskinesia (i.e., fine, wormlike movements or rapid protrusions of the tongue, chewing
motions, lip smacking). Patients on long-term therapy are high risk. Teach patients and responsible family members about symptoms
because early reporting is essential.
- Lab tests: Obtain differential blood cell counts and liver; and kidney function studies.
- ECG and ophthalmologic examination are recommended prior to initiation and periodically during therapy.
- Suspect hypersensitivity, withhold drug, and report to physician if jaundice appears between weeks 2 and 4.
- Monitor I&O ratio and bowel elimination pattern.
- Be alert to potential for altered tolerance to environmental temperature changes. Be cautious with external heat devices.
Conditioned avoidance behavior may be depressed, and a severe burn could result.
Patient & Family Education
- Make all position changes slowly and in stages, particularly from recumbent to upright posture, and to lie down or sit down
if light-headedness or dizziness occurs.
- Do not drive or engage in potentially hazardous activities until response to drug is known. Drug may produce hypotension (dizziness,
light-headedness), and sedation especially during early therapy.
- Discontinue drug and report to physician immediately if jaundice appears between weeks 2 and 4.
- Avoid long exposure to sunlight and to sunlamps. Photosensitivity results in skin color changes from brown to blue-gray.
- Adhere to dosage regimen strictly. Contact physician before changing it for any reason.
- Discontinue gradually over a period of several weeks following prolonged therapy.
- Avoid OTC drugs unless physician prescribes them.
- Be aware that perphenazine may discolor urine reddish brown.
- Do not breast feed while taking this drug without consulting physician.
1%)
Canadian drug name; 
Prototype drug