Amitriptyline

A tricyclic antidepressant used for depression, chronic pain, migraine, and sleep disorders.

What is Amitriptyline?

Amitriptyline is a tricyclic antidepressant (TCA) that affects serotonin and norepinephrine levels in the brain.

It is widely used not only for depression but also for chronic pain and sleep disorders.

History & Background

Amitriptyline was introduced in the 1960s and remains in use due to its effectiveness in mood disorders and neuropathic pain.

Chemical Structure & Properties

• IUPAC name: 3-(10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene)-N,N-dimethylpropan-1-amine
• Molecular formula: C₂₀H₂₃N
• Molar mass: 277.40 g/mol
• Functional groups: Tertiary amine, tricyclic ring system

Mechanism of Action

Amitriptyline works by:

• Inhibiting serotonin reuptake
• Inhibiting norepinephrine reuptake
• Enhancing mood and pain modulation

Pharmacokinetics

• Absorption: Well absorbed orally
• Peak plasma time: 2–12 hours
• Half-life: 10–28 hours
• Metabolism: Liver (CYP enzymes)
• Excretion: Urine

Medical Uses

• Major depressive disorder
• Neuropathic pain
• Migraine prophylaxis
• Fibromyalgia
• Insomnia (low dose)

Dosage Guidelines

Depression: 75–150 mg/day

Pain / Migraine: 10–50 mg at night

⚠️ Start low and increase gradually.

Side Effects

• Drowsiness
• Dry mouth
• Constipation
• Weight gain

Warnings & Precautions

• Risk of cardiac arrhythmias
• Avoid overdose
• Use caution in elderly patients

Drug Interactions

• MAO inhibitors
• Alcohol
• Other antidepressants

Frequently Asked Questions

Is amitriptyline for sleep? – Yes, at low doses.

Is it addictive? – No.

Does it cause drowsiness? – Common.

Is it safe long-term? – Yes, with monitoring.

⚠️ Educational content only. Not a substitute for professional medical advice.