Home Drug Guide Thioridazine Hydrochloride

Drug Guide

Generic Name

Thioridazine Hydrochloride

Brand Names Mellaril, Thioridazine Hydrochloride Intensol

Classification

Therapeutic: Antipsychotic, typical (first-generation)

Pharmacological: Phenothiazine antipsychotic

FDA Approved Indications

  • Schizophrenia

Mechanism of Action

Thioridazine blocks dopamine receptors (primarily D2) in the brain, thereby reducing psychotic symptoms. It also has anticholinergic, antihistaminic, and antiadrenergic properties.

Dosage and Administration

Adult: Initially 50-100 mg 2-3 times daily, titrated based on response and tolerability. Maintenance doses generally range from 100-300 mg daily, divided into 2-3 doses.

Pediatric: Use is not well established in pediatric patients; consult specific guidelines.

Geriatric: Start at lower doses, typically 25-50 mg daily, due to increased sensitivity and risk of adverse effects.

Renal Impairment: Use with caution; no specific adjustment, but monitor closely.

Hepatic Impairment: Use cautiously; monitor for increased effects or toxicity.

Pharmacokinetics

Absorption: Well absorbed from GI tract

Distribution: Widely distributed, crosses blood-brain barrier and placenta, enters breast milk

Metabolism: Primarily hepatic via CYP2D6 and other enzymes

Excretion: Metabolites excreted in urine and feces

Half Life: Approximately 12-20 hours, can be longer in elderly or hepatic impairment

Contraindications

  • Pigmentary retinopathy
  • Known hypersensitivity to phenothiazines

Precautions

  • Use cautiously in patients with cardiac disorders, history of seizures, or blood dyscrasias. Avoid in pregnancy unless clearly needed; utilize contraception during therapy. Monitor for neuroleptic malignant syndrome and significant changes in blood pressure.

Adverse Reactions - Common

  • Sedation (Common)
  • Dry mouth (Common)
  • Extrapyramidal symptoms (Common)
  • Orthostatic hypotension (Common)

Adverse Reactions - Serious

  • QT prolongation and risk of torsades de pointes (Serious; monitor EKG)
  • Neuroleptic malignant syndrome (Rare but serious)
  • Retinal pigmentary degeneration leading to vision loss (Rare; black box warning)

Drug-Drug Interactions

  • Other QT prolonging agents
  • CNS depressants
  • Anticholinergic drugs

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for EPS, cardiac status, vision changes, and signs of NMS.

Diagnoses:

  • Risk for falls due to orthostatic hypotension
  • Risk for neuroleptic malignant syndrome
  • Impaired visual perception

Implementation: Administer with meals if GI upset occurs and monitor EKG during therapy.

Evaluation: Assess for therapeutic response and adverse effects regularly.

Patient/Family Teaching

  • Take medication exactly as prescribed and do not stop abruptly.
  • Report any vision changes, signs of movement disorders, or cardiac symptoms immediately.
  • Avoid alcohol and CNS depressants. Advise on sun protection due to photosensitivity.

Special Considerations

Black Box Warnings:

  • Retinal pigmentary degeneration leading to vision loss
  • QT prolongation which may lead to torsades de pointes

Genetic Factors: Metabolism primarily involves CYP2D6; poor metabolizers may require dose adjustments.

Lab Test Interference: May cause false-positive tests for ketones in urine.

Overdose Management

Signs/Symptoms: Severe hypotension, respiratory depression, extrapyramidal symptoms, coma, myocarditis, QT prolongation, arrhythmias.

Treatment: Supportive care, continuous cardiac monitoring, activated charcoal if ingestion recent, sedation with benzodiazepines for agitation, equipped resuscitation equipment for life-threatening arrhythmias.

Storage and Handling

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

Stability: Stable under proper storage conditions for shelf life specified by manufacturer.

🛡️ 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.