TCA·Psychiatry - Antidepressants

amiTRIPTYLine

Major Depressive Disorder

PBSTCAEndep10 mg tabletS4+1

No source link confirmed for this record yet. Its own source notes are under Additional.

At a glance

Max Dose

150 mg/day

Half-life

20 h

High risk: Toxicity in OD

CRITICAL

Caution: Anticholinergic

SEVERE

Cautions

Avoid / Cautions

Recent myocardial infarction, heart block, severe hepatic impairment, concurrent MAOIs. Pregnancy Category C.

Where it stands

Rapid Summary

Overview

Tricyclic Antidepressant (TCA). The original, 'dirty' but incredibly effective drug. Used rarely for depression now, but heavily utilized in micro-doses for chronic nerve pain and migraine prevention.

Clinical Focus

Fatal in overdose. TCAs block cardiac sodium channels causing widening QRS, lethal arrhythmias, and profound anticholinergic coma.

Bottom Line

Amitriptyline is a TCA widely used at low dose for neuropathic pain, migraine prophylaxis, and insomnia, but is cardiotoxic in overdose and has significant anticholinergic burden in elderly.

Formulation & Access

Brand Names

Endep

Oral Routes

Tablets (10 mg, 25 mg, 50 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Major Depressive Disorder.

Off-Label

OFF

Neuropathic pain, migraine prophylaxis, IBS-D, severe insomnia.

Clinical Place

First-line low-dose adjunct for chronic nerve pain (e.g., post-herpetic neuralgia, diabetic neuropathy).

Quick reference

Class & Role

TCA — Tricyclic Antidepressant (TCA).

Route / Formulation

Tablets (10 mg, 25 mg, 50 mg). (Endep)

Usual Dose & Max

Start PO 10-25 mg NOCTE. Titrate up every 1-2 weeks. Target 25-75 mg NOCTE. Max 150 mg/day (Depression).

Key Indication Doses

Neuropathic Pain / Migraine: Start PO 10-25 mg NOCTE. Titrate up every 1-2 weeks. Target 25-75 mg NOCTE. Depression: Start PO 50 mg NOCTE. Titrate to 100-150 mg/day. (Rarely used due to safer SSRIs). Elderly / Frail: Avoid if possible. If required, strictly max 10 mg NOCTE due to severe falls/delirium risk.

Best Uses

Amitriptyline is a TCA widely used at low dose for neuropathic pain, migraine prophylaxis, and insomnia, but is cardiotoxic in overdose and has significant anticholinergic burden in elderly.

Key Risks

Cardiovascular: QTc prolongation, QRS widening, orthostatic hypotension, tachycardia. Fatal arrhythmias in overdose. Neurological: Profound morning hangover/sedation, delirium (especially elderly), lowers seizure threshold. Gastrointestinal: Severe dry mouth, severe constipation, urinary retention (Anticholinergic toxidrome). Metabolic: Weight gain (H1 blockade).

Key Interactions

MAOIs, Tramadol (Serotonin Syndrome). Additive anticholinergic burden (Oxybutynin, Promethazine). CYP2D6 inhibitors (Fluoxetine, Paroxetine) spike TCA blood levels into the toxic range.

Monitoring

Baseline ECG (Check QTc and QRS width) before escalating doses. Monitor for urinary retention and severe constipation.

Clinical Pearl

If a patient overdoses on Amitriptyline, their QRS will widen on the ECG. You MUST push IV Sodium Bicarbonate. It overwhelms the sodium channel blockade and saves the heart.

Access

Endep10 mg tablet

Brand: Endep
Formulation: Tablets (10 mg, 25 mg, 50 mg).

From this page

No calculator, monitoring schedule or factsheet is linked to this medicine page yet.

TCA·Psychiatry - Antidepressants

amiTRIPTYLine

Major Depressive Disorder

PBSTCAEndep10 mg tabletS4+1

No source link confirmed for this record yet. Its own source notes are under Additional.

At a glance

Max Dose

150 mg/day

Half-life

20 h

High risk: Toxicity in OD

CRITICAL

Caution: Anticholinergic

SEVERE

Cautions

Avoid / Cautions

Recent myocardial infarction, heart block, severe hepatic impairment, concurrent MAOIs. Pregnancy Category C.

Where it stands

Rapid Summary

Overview

Clinical Focus

Fatal in overdose. TCAs block cardiac sodium channels causing widening QRS, lethal arrhythmias, and profound anticholinergic coma.

Bottom Line

Amitriptyline is a TCA widely used at low dose for neuropathic pain, migraine prophylaxis, and insomnia, but is cardiotoxic in overdose and has significant anticholinergic burden in elderly.

Formulation & Access

Brand Names

Endep

Oral Routes

Tablets (10 mg, 25 mg, 50 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Major Depressive Disorder.

Off-Label

OFF

Neuropathic pain, migraine prophylaxis, IBS-D, severe insomnia.

Clinical Place

First-line low-dose adjunct for chronic nerve pain (e.g., post-herpetic neuralgia, diabetic neuropathy).

Quick reference

Class & Role

TCA — Tricyclic Antidepressant (TCA).

Route / Formulation

Tablets (10 mg, 25 mg, 50 mg). (Endep)

Usual Dose & Max

Start PO 10-25 mg NOCTE. Titrate up every 1-2 weeks. Target 25-75 mg NOCTE. Max 150 mg/day (Depression).

Key Indication Doses

Best Uses

Amitriptyline is a TCA widely used at low dose for neuropathic pain, migraine prophylaxis, and insomnia, but is cardiotoxic in overdose and has significant anticholinergic burden in elderly.

Key Risks

Key Interactions

MAOIs, Tramadol (Serotonin Syndrome). Additive anticholinergic burden (Oxybutynin, Promethazine). CYP2D6 inhibitors (Fluoxetine, Paroxetine) spike TCA blood levels into the toxic range.

Monitoring

Baseline ECG (Check QTc and QRS width) before escalating doses. Monitor for urinary retention and severe constipation.

Clinical Pearl

If a patient overdoses on Amitriptyline, their QRS will widen on the ECG. You MUST push IV Sodium Bicarbonate. It overwhelms the sodium channel blockade and saves the heart.

Access

Endep10 mg tablet

Brand: Endep
Formulation: Tablets (10 mg, 25 mg, 50 mg).

From this page

No calculator, monitoring schedule or factsheet is linked to this medicine page yet.