Home Drug Guide Perphenazine

Drug Guide

Generic Name

Perphenazine

Brand Names Trilafon

Classification

Therapeutic: Antipsychotic

Pharmacological: Phenothiazine (Typical antipsychotic)

FDA Approved Indications

  • Schizophrenia
  • Nausea and vomiting (off-label)

Mechanism of Action

Perphenazine blocks dopamine D2 receptors in the brain, thereby reducing symptoms of psychosis and controlling nausea.

Dosage and Administration

Adult: Initially 4-8 mg three times daily. Dosage can be adjusted based on response and tolerability.

Pediatric: Use not generally recommended; consult a specialist.

Geriatric: Start with lower doses, such as 2-4 mg two to three times daily, due to increased sensitivity.

Renal Impairment: Adjust doses carefully; no specific guidelines well established.

Hepatic Impairment: Use cautiously; no specific dose adjustments established.

Pharmacokinetics

Absorption: Well absorbed from gastrointestinal tract.

Distribution: Widely distributed, crosses blood-brain barrier.

Metabolism: Hepatic via CYP450 enzymes.

Excretion: Primarily via urine, some in feces.

Half Life: 6-12 hours, variable.

Contraindications

  • Comprise hypersensitivity to phenothiazines or other components.
  • Comorbid Parkinson's disease.
  • Bone marrow suppression.

Precautions

  • Use cautiously in elderly, due to risk of sedation, orthostatic hypotension, and increased mortality in elderly with dementia-related psychosis.
  • Monitor for extrapyramidal symptoms, tardive dyskinesia, neuroleptic malignant syndrome, and other adverse effects.

Adverse Reactions - Common

  • Drowsiness (Common)
  • Extrapyramidal symptoms (EPS) (Common)
  • Dry mouth (Common)
  • Blurred vision (Common)

Adverse Reactions - Serious

  • Neuroleptic malignant syndrome (NMS) (Rare)
  • Tardive dyskinesia (Rare)
  • Seizures (Rare)
  • Blood dyscrasias (e.g., agranulocytosis) (Rare)

Drug-Drug Interactions

  • Centrally acting depressants (additive sedation)
  • Anticholinergic medications (increased anticholinergic effects)

Drug-Food Interactions

  • Alcohol (enhanced sedation)

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor mental status, extrapyramidal symptoms, blood pressure, and signs of NMS.

Diagnoses:

  • Risk for falls (due to sedation and orthostatic hypotension)
  • Risk for neurological injury related to EPS or NMS

Implementation: Administer with food to decrease gastrointestinal upset; monitor for adverse reactions.

Evaluation: Assess effectiveness in controlling psychotic symptoms and side effects regularly.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Do not stop medication abruptly.
  • Report any signs of EPS, NMS, or unusual movements.
  • Avoid alcohol and operating heavy machinery until response is known.

Special Considerations

Black Box Warnings:

  • Increased mortality in elderly patients with dementia-related psychosis.
  • Tardive dyskinesia may be irreversible.

Genetic Factors: Metabolism variability may influence drug levels; CYP450 enzyme activity may affect response.

Lab Test Interference: May cause false-positive results in certain laboratory tests.

Overdose Management

Signs/Symptoms: Extrapyramidal symptoms, hypotension, sedation, seizures, respiratory depression, coma.

Treatment: Supportive care, monitor vital signs, activated charcoal if early, symptomatic treatment for seizures or other adverse effects.

Storage and Handling

Storage: Store at room temperature, away from light and moisture.

Stability: Stable for usual shelf life, check packaging for expiration date.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.