Venlafaxine XR

SNRI·Psychiatry - Antidepressants

Major Depressive Disorder, GAD, Panic Disorder

PBSSNRIEfexor-XR, Elaxine PR37.5 mgS4+1

Max Dose

225 mg/day

Half-life

5 h (Act: 11h)

Hypertension

DOSE-DEP

Withdrawal

SEVERE

Rapid Summary

Overview

Serotonin-Noradrenaline Reuptake Inhibitor (SNRI). Highly effective for severe/refractory depression. The noradrenaline blockade kicks in at higher doses, providing an activating, energy-boosting effect.

Maximum Dose

Max 225 mg/day (Specialist psych regimens may occasionally push to 375 mg).

Clinical Focus

Missing even a single dose triggers a horrifying withdrawal syndrome ('brain zaps', severe vertigo, flu-like crash).

Bottom Line

Venlafaxine XR is a potent SNRI for depression, GAD, and neuropathic pain, but causes dose-dependent hypertension requiring BP monitoring and has a severe discontinuation syndrome if stopped abruptly.

Formulation & Access

Brand Names

Efexor-XR, Elaxine PR

Oral Routes

Do not crush

Extended Release Capsules (37.5 mg, 75 mg, 150 mg). Do not crush. Patient may see intact ghost capsule in stool.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Major Depressive Disorder, GAD, Panic Disorder.

Clinical Place

Second-line after SSRI failure, or first-line for severe melancholic, low-energy depression.

Quick reference

Class & Role

SNRI — Serotonin-Noradrenaline Reuptake Inhibitor (SNRI).

Route / Formulation

Extended Release Capsules (37.5 mg, 75 mg, 150 mg). Do not crush. Patient may see intact ghost capsule in stool. (Efexor-XR, Elaxine PR)

Usual Dose & Max

Start PO 75 mg OD (XR capsule). Titrate by 75 mg increments every 2-4 weeks. Max 225 mg/day.

Key Indication Doses

Depression / GAD / Panic: Start PO 75 mg OD (XR capsule). Titrate by 75 mg increments every 2-4 weeks. Max 225 mg/day. Severe Anxiety / Frail: Start PO 37.5 mg OD (XR capsule) for the first week to blunt intense initial anxiety/nausea.

Best Uses

Avoid / Cautions

Concurrent MAOI use (Fatal Serotonin Syndrome), uncontrolled severe hypertension. Pregnancy Category B2. Can cause severe withdrawal symptoms in the neonate if used until term.

Key Risks

Neurological: Discontinuation syndrome ('Brain zaps', dizziness, sensory disturbances, crying spells). HIGH — Insomnia, severe sweating, tremor. Cardiovascular: Dose-dependent hypertension and tachycardia (due to noradrenaline excess). Gastrointestinal: Nausea (severe upon initiation).

Key Interactions

MAOIs, Tramadol, St John's Wort. Extreme risk of Serotonin Syndrome. NSAIDs (Bleeding risk).

Monitoring

Baseline and routine BP and HR checks. If a patient develops hypertension > 150/90, reduce the dose or cease. Routine U&E (sodium) for SIADH risk.

Clinical Pearl

If you prescribe 75mg of Venlafaxine, you are effectively just prescribing a highly toxic, hard-to-stop SSRI. You MUST push the dose to 150mg or 225mg to actually unlock the noradrenaline (SNRI) benefits.

Access

Efexor-XR, Elaxine PR37.5 mg

Brand: Efexor-XR, Elaxine PR
Formulation: Extended Release Capsules (37