Home Drug Guide Chlorpromazine

Drug Guide

Generic Name

Chlorpromazine

Brand Names Thorazine

Classification

Therapeutic: Antipsychotic, typical

Pharmacological: Phenothiazine antipsychotic

FDA Approved Indications

  • Schizophrenia
  • Manic-depressive illness (short-term adjunct)
  • Intractable hiccups
  • Nausea and vomiting (preoperative antiemetic)
  • Tic disorders

Mechanism of Action

Chlorpromazine blocks dopamine D2 receptors in the brain, reducing dopaminergic transmission, which alleviates psychotic symptoms.

Dosage and Administration

Adult: Typically 25-50 mg two to three times daily; dosage may be adjusted based on clinical response and tolerability.

Pediatric: Use is limited; dosing varies and should be determined by a specialist.

Geriatric: Start at lower doses (e.g., 25 mg daily) due to increased sensitivity and risk of adverse effects; titrate cautiously.

Renal Impairment: Adjust dose based on clinical response and tolerability; no specific guidelines, monitor closely.

Hepatic Impairment: Use with caution; no specific dose adjustments, start low and go slow.

Pharmacokinetics

Absorption: Well absorbed from the gastrointestinal tract

Distribution: Widely distributed in body tissues; crosses blood-brain barrier and placenta

Metabolism: Hepatic metabolism via hydroxylation and conjugation; CYP450 involvement varies

Excretion: Primarily via renal route as metabolites

Half Life: About 16-30 hours, variable depending on individual factors and chronicity of use

Contraindications

  • Comcurrent use with CNS depressants or alcohol
  • Comatose states
  • Bone marrow suppression

Precautions

  • Use cautiously in elderly patients (due to risk of falls, sedation, and neuroleptic malignant syndrome)
  • History of Parkinson’s disease
  • Seizure disorders
  • Prolonged QT interval

Adverse Reactions - Common

  • Sedation (Very common)
  • Dizziness (Common)
  • Dry mouth (Common)
  • Extrapyramidal symptoms (restlessness, tremors) (Common)

Adverse Reactions - Serious

  • Neuroleptic malignant syndrome (fever, rigidity, altered mental status) (Rare)
  • QT prolongation and arrhythmias (Rare)
  • Agranulocytosis (Rare)
  • Seizures (Rare)

Drug-Drug Interactions

  • CNS depressants (additive sedation)
  • Anticholinergics (potential for increased side effects)
  • Other QT-prolonging agents (risk of arrhythmias)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor mental status, neurological signs, cardiovascular status (ECG if indicated), and for adverse effects.

Diagnoses:

  • Risk for falls related to sedation and orthostatic hypotension.
  • Ineffective coping related to psychiatric symptoms.

Implementation: Administer with food or milk to decrease gastrointestinal irritation. Monitor for EPS and NMS.

Evaluation: Assess effectiveness in symptom control and monitor for adverse effects; adjust dose accordingly.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report any signs of movement disorders, fever, muscle rigidity, or unusual blood work to a healthcare provider.
  • Avoid alcohol and CNS depressants.
  • Be aware of the potential for sedation and avoid driving until sedation levels are known.

Special Considerations

Black Box Warnings:

  • Increased mortality in elderly patients with dementia-related psychosis

Genetic Factors: Dosing may need adjustment based on CYP450 enzyme activity.

Lab Test Interference: May cause false positives in urine drug screens.

Overdose Management

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

Treatment: Supportive care, gastric lavage if early, activated charcoal, IV fluids, and monitoring of vital signs. No specific antidote.

Storage and Handling

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

Stability: Stable under recommended conditions for shelf life specified in packaging.

🛡️ 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.