Home Drug Guide Amitriptyline Hydrochloride

Drug Guide

Generic Name

Amitriptyline Hydrochloride

Brand Names Elavil, Endep, Amitril, Amitid

Classification

Therapeutic: Antidepressant, Tricyclic

Pharmacological: Serotonin-Norepinephrine Reuptake Inhibitor (SNRI)

FDA Approved Indications

  • Depressive disorder (major depression)
  • Prevention of migraine headaches
  • Chronic pain management (e.g., neuropathic pain)
  • Insomnia (off-label)

Mechanism of Action

Amitriptyline inhibits the reuptake of serotonin and norepinephrine, increasing their levels in the synaptic cleft, which enhances neurotransmission and alleviates depressive symptoms. It also has anticholinergic and antihistaminic properties.

Dosage and Administration

Adult: Typically 25-50 mg at bedtime, titrated up to 150-300 mg/day as needed.

Pediatric: Not generally recommended for children.

Geriatric: Start at lower doses (e.g., 10-25 mg at bedtime) due to increased sensitivity and risk of side effects.

Renal Impairment: Use with caution; dose adjustments may be necessary.

Hepatic Impairment: Use with caution; consider lower doses.

Pharmacokinetics

Absorption: Well absorbed orally.

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

Metabolism: Hepatically metabolized primarily via CYP2D6, CYP1A2, and CYP3A4 enzymes.

Excretion: Excreted mainly in urine.

Half Life: Approximately 10-28 hours.

Contraindications

  • Use in patients with recent myocardial infarction, as it may cause arrhythmias.
  • History of hypersensitivity to amitriptyline.

Precautions

  • Suicide risk, especially in young adults and adolescents.
  • Caution in patients with seizures, glaucoma, urinary retention, or bipolar disorder.

Adverse Reactions - Common

  • Dry mouth (Frequent)
  • Drowsiness (Common)
  • Dizziness (Common)
  • Constipation (Common)
  • Weight gain (Common)

Adverse Reactions - Serious

  • Cardiac conduction abnormalities (arrhythmias) (Rare)
  • Serotonin syndrome (Rare)
  • Suicidal thoughts or behavior (Possible in young patients)

Drug-Drug Interactions

  • MAO inhibitors (risk of serotonin syndrome)
  • CNS depressants (additive sedative effect)
  • Anticholinergic drugs (anticholinergic toxicity)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor mental health status, suicidal ideation, cardiac status, and baseline ECG if indicated.

Diagnoses:

  • Risk for injury due to orthostatic hypotension or sedation
  • Risk for injury due to anticholinergic effects

Implementation: Administer at bedtime to reduce sedation; gradually titrate dose; monitor for therapeutic effects and adverse effects.

Evaluation: Assess for improvements in depressive symptoms and pain; monitor for adverse reactions and toxicity.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Do not stop abruptly to avoid withdrawal symptoms.
  • Be cautious of drowsiness and avoid operating machinery until response is known.
  • Report worsening depression or suicidal thoughts immediately.
  • Use caution when driving or engaging in hazardous activities.

Special Considerations

Black Box Warnings:

  • Increased risk of suicidal thoughts and actions in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders.
  • Serious skin reactions (erythema multiforme, toxic epidermal necrolysis).

Genetic Factors: Metabolism greatly affected by CYP2D6 phenotype; poor metabolizers may have increased plasma levels.

Lab Test Interference: May affect blood glucose and other laboratory tests.

Overdose Management

Signs/Symptoms: Altered mental status, hallucinations, seizures, tachycardia, hypotension, arrhythmias, cardiac conduction delays, coma.

Treatment: Supportive care, activated charcoal, sodium bicarbonate for cardiac toxicity; specific antidote is not available.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F).

Stability: Stable under normal storage 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.