Home Drug Guide Doxepin Hydrochloride

Drug Guide

Generic Name

Doxepin Hydrochloride

Brand Names Sinequan, Zonalon, Silenor

Classification

Therapeutic: Antidepressant, Tricyclic

Pharmacological: Tricyclic antidepressant (TCA)

FDA Approved Indications

  • Major depressive disorder
  • Anxiety disorders
  • Insomnia (Silenor)
  • Pruritus (Zonalon)

Mechanism of Action

Doxepin inhibits the reuptake of norepinephrine and serotonin, increasing their levels in the brain. It also has antihistamine properties contributing to sedative effects.

Dosage and Administration

Adult: Various doses depending on indication, e.g., for depression typically 75-300 mg/day in divided doses or at bedtime.

Pediatric: Not generally recommended for pediatric depression. Use with caution if prescribed for other indications.

Geriatric: Start at lower doses due to increased sensitivity and risk of side effects.

Renal Impairment: Adjust dose cautiously; consider renal function.

Hepatic Impairment: Use with caution; dose adjustment may be necessary.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses the blood-brain barrier.

Metabolism: Primarily hepatic via CYP450 enzymes.

Excretion: Via urine as metabolites and unchanged drug.

Half Life: Approx. 8-24 hours, variable.

Contraindications

  • Recent myocardial infarction
  • Use with monoamine oxidase inhibitors (MAOIs)

Precautions

  • History of urinary retention, angle-closure glaucoma, seizure disorders, bipolar disorder, suicidality, and hepatic impairment.

Adverse Reactions - Common

  • Drowsiness (Common)
  • Dizziness (Common)
  • Dry mouth (Common)
  • Constipation (Common)

Adverse Reactions - Serious

  • Suicidal thoughts (Less common but serious)
  • Serotonin syndrome (Rare)
  • Cardiac arrhythmias (Rare)
  • Hepatotoxicity (Rare)

Drug-Drug Interactions

  • Monoamine oxidase inhibitors (MAOIs)
  • Other CNS depressants
  • QT prolonging agents

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for depression severity, suicidal ideation, cardiac status, hydration status.

Diagnoses:

  • Risk for injury related to sedation or orthostatic hypotension.
  • Risk for cardiac arrhythmias.

Implementation: Administer at bedtime for sedative effects. Monitor cardiac function if necessary.

Evaluation: Assess for therapeutic response and adverse effects.

Patient/Family Teaching

  • Do not discontinue abruptly to avoid withdrawal symptoms.
  • Warn about drowsiness and advise against operating heavy machinery.
  • Avoid alcohol and CNS depressants.
  • Report worsening depression or suicidality.

Special Considerations

Black Box Warnings:

  • Increased risk of suicidal thinking and behavior in children, adolescents, and young adults.

Genetic Factors: Consider CYP2D6 metabolism status for dose considerations.

Lab Test Interference: N/A

Overdose Management

Signs/Symptoms: Seizures, hallucinations, severe hypotension, coma.

Treatment: Supportive care, activated charcoal if ingestion recent, sodium bicarbonate for cardiotoxicity, and intensive medical monitoring.

Storage and Handling

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

Stability: Stable under recommended conditions.

🛡️ 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.