perphenazine

perphenazine

 [per-fen´ah-zēn]

a phenothiazine compound used orally and intramuscularly as an antipsychotic agent and antiemetic.

perphenazine

Apo-Perphenazine (CA), Fentazin (UK)

Pharmacologic class: Phenothiazine, dopaminergic antagonist

Therapeutic class: Antipsychotic, antiemetic

Pregnancy risk category NR

Action

Unknown. Thought to antagonize dopamine and serotonin type 2 in CNS. Also antagonizes muscarinic receptors in respiratory tract, causing cholinergic activation.

Availability

Tablets: 2 mg, 4 mg, 8 mg, 16 mg

Indications and dosages

➣ Schizophrenia in nonhospitalized patients

Adults and children older than age 12: Initially, 4 to 8 mg P.O. t.i.d.

➣ Schizophrenia in hospitalized patients

Adults and children older than age 12: Initially, 8 to 16 mg P.O. two to four times daily, increased p.r.n.; avoid dosages greater than 64 mg daily.

➣ Severe nausea and vomiting

Adults: 8 to 16 mg P.O. daily in divided doses, to a maximum of 24 mg.

Off-label uses

• Intractable hiccups

Contraindications

• Hypersensitivity to drug, its components, or related compounds

• Blood dyscrasias

• Bone marrow depression

• Hepatic damage

• Subcortical damage

• Coma

• Concurrent use of high-dose CNS depressants

Precautions

Use cautiously in:

• respiratory disorders, hepatic or renal dysfunction, breast cancer, alcohol withdrawal symptoms, suicidal tendency, surgery

• patients taking CNS depressants or anticholinergics

• elderly patients

• pregnant or breastfeeding patients

• children younger than age 12.

Administration

• Give with food to avoid GI upset.

Adverse reactions

CNS: drowsiness, dizziness, insomnia, vertigo, headache, hyperactivity, nocturnal confusion, bizarre dreams, tremor, ataxia, slurring, exacerbation of psychotic symptoms, paranoid reactions, parkin-sonism, dystonias, akathisia, tardive dyskinesia, hyperreflexia, cerebrospinal fluid abnormality, catatonic-like state, paradoxical stimulation, seizures, neuroleptic malignant syndrome

CV: hypotension, orthostatic hypotension, hypertension, peripheral edema, ECG changes, tachycardia, bradycardia, cardiac arrest, heart failure

EENT: glaucoma, blurred vision, miosis, mydriasis, corneal and lens deposits, pigmentary retinopathy, oculogyric crisis, photophobia, nasal congestion, dysphagia

GI: nausea, vomiting, diarrhea, constipation, obstipation, abnormal tongue color or movement, dry mouth, anorexia, adynamic ileus

GU: dark urine, urinary retention, urinary frequency, urinary incontinence, bladder paralysis, galactorrhea, lactation, breast enlargement, menstrual irregularities, inhibited ejaculation, libido changes

Hematologic: hemolytic anemia, leukopenia, agranulocytosis, thrombocytopenic purpura

Hepatic: jaundice, biliary stasis

Metabolic: hyponatremia, glycosuria, hyperglycemia, hypoglycemia, syndrome of inappropriate antidiuretic hormone secretion, pituitary tumor

Musculoskeletal: numbness and aching of arms and legs

Respiratory: dyspnea, suppressed cough reflex, asthma, bronchospasm, laryngospasm, laryngeal edema

Skin: urticaria, pallor, erythema, eczema, pruritus, perspiration, pigmentation changes, photosensitivity, angioedema, exfoliative dermatitis

Other: increased appetite, weight gain, fever, systemic lupus erythematosuslike syndrome, hypersensitivity reactions including anaphylactoid reaction

Interactions

Drug-drug. Anticholinergics: increased risk of adverse anticholinergic reactions

CNS depressants: increased perphenazine effects, increased adverse CNS reactions

Tricyclic antidepressants: increased perphenazine blood level, greater risk of adverse reactions

Drug-diagnostic tests. Eosinophils, liver function tests: increased values Glucose: increased or decreased level Granulocytes, hemoglobin, platelets, sodium, white blood cells: decreased levels

Pregnancy test: false-positive result

Drug-herbs. Kava: dystonic reactions

St. John's wort: photosensitivity

Yohimbe: yohimbe toxicity

Drug-behaviors. Alcohol use: increased CNS depression

Sun exposure: increased risk of photosensitivity reaction

Patient monitoring

☞ Watch for anaphylactoid reaction and angioedema. Monitor neurologic status; stay alert for signs and symptoms of neuroleptic malignant syndrome (high fever, unstable blood pressure, stupor, muscle rigidity, autonomic dysfunction), parkinsonian symptoms, and catatonic-like state.

• Monitor cardiovascular status and vital signs periodically.

☞ Evaluate respiratory status, especially for dyspnea and airway spasm.

☞ Monitor CBC, glucose level, and liver function tests. Watch for evidence of blood dyscrasias.

Patient teaching

• Explain importance of combining drug therapy with psychotherapy.

• Tell patient to take exactly as prescribed and to report adverse reactions promptly.

• Instruct patient to avoid sun exposure and to wear sunscreen outdoors to prevent photosensitivity reaction.

• Advise patient to consult prescriber before taking other prescription drugs or over-the-counter preparations.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects him.

• Instruct patient to avoid alcohol, smoking, caffeine, and herbs.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.

per·phe·na·zine

(per-fen'ă-zēn),

An antipsychotic of the phenothiazine type.

perphenazine

(pər-fĕn′ə-zēn′)

n.

A crystalline compound, C₂₁H₂₆ClN₃OS, used as a tranquilizer especially in the treatment of psychosis and to prevent or alleviate nausea and vomiting.

perphenazine

Etrafon, Trilafon^® Pharmacology A phenothiazine and tricyclic antidepressant combination used to manage anxiety, depression, agitation, severe N&V, hiccups, pain Adverse effects Extrapyramidal symptoms–involuntary movement–opisthotonus, trismus, torticollis, retrocollis, aching, numbness of limbs, motor restlessness, oculogyric crisis, hyperreflexia, dystonia, sedative effects, jaundice, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenic purpura, pancytopenia. See Mitriptyline.

perphenazine

A phenothiazine derivative drug used in the treatment of SCHIZOPHRENIA and other psychotic conditions. It is also used to relieve severe vomiting and control persistent hiccups. A brand name is Fentazin.