SNRI Antidepressant Pregnancy: There are no adequate data in pregnant women; must only be administered to pregnant women if the expected benefits outweigh any possible risk. Discontinuation symptoms and neonatal complications (tube feeding, respiratory support, prolonged hospitalisation) may occur if used until or shortly before birth. Excreted in breast milk - decide whether to continue breast-feeding or treatment, taking the benefits of each into account.

Venlafaxine

Brand names: Efexor XL

Used in: Depression & Anxiety

Venlafaxine is a serotonin-noradrenaline reuptake inhibitor (SNRI) used for depression and some anxiety disorders, often after an SSRI has not worked.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Major depressive episodes: recommended starting dose 75 mg once daily (prolonged release), increased if needed up to a maximum of 375 mg/day. Generalised anxiety disorder and social anxiety disorder: 75 mg once daily, up to a maximum of 225 mg/day. Panic disorder: 37.5 mg/day for 7 days, then 75 mg/day, up to a maximum of 225 mg/day.

Route: Oral (prolonged-release capsules; take with food, swallow whole - do not divide, crush, chew or dissolve)

Frequency: Once daily, at approximately the same time each day

Max: 375 mg/day (major depressive episodes); 225 mg/day (generalised anxiety disorder, social anxiety disorder, panic disorder)

Dose increases can be made at intervals of 2 weeks or more (for depression, if clinically warranted by symptom severity, not less than 4 days). Dose increments only after clinical evaluation because of dose-related adverse effects; maintain the lowest effective dose. Treat for a sufficient period, usually several months or longer; antidepressant treatment should continue for at least six months following remission. ELDERLY: 'No specific dose adjustments of venlafaxine are considered necessary based on patient age alone. However, caution should be exercised in treating the elderly (e.g., due to the possibility of renal impairment, the potential for changes in neurotransmitter sensitivity and affinity occurring with aging). The lowest effective dose should always be used, and patients should be carefully monitored when an increase in the dose is required.' Hepatic impairment: mild to moderate - consider a 50% dose reduction; severe - consider a reduction of more than 50%. Discontinuation: avoid abrupt stopping - reduce gradually over at least one to two weeks. Switching from immediate-release: switch at the nearest equivalent daily dosage (e.g. 37.5 mg twice daily to 75 mg once daily). PAEDIATRIC: not recommended in children and adolescents under 18 years - efficacy was not demonstrated and safety for other indications is not established.

Dose adjustments

Renal

No change in dosage is necessary for glomerular filtration rate 30-70 mL/minute, although caution is advised. For patients requiring haemodialysis and those with severe renal impairment (GFR <30 mL/min), the dose should be reduced by 50%; individualisation of dosage may be desirable.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION Initial Treatment The recommended starting dose for venlafaxine tablets is 75 mg/day, administered in two or three divided doses, taken with food. Depending on tolerability and the need for further clinical effect, the dose may be increased to 150 mg/day. If needed, the dose should be further increased up to 225 mg/day. When increasing the dose, increments of up to 75 mg/day should be made at intervals of no less than 4 days. In outpatient settings there was no evidence of usefulness of doses greater than 225 mg/day for moderately depressed patients, but more severely depressed inpatients responded to a mean dose of 350 mg/day. Certain patients, including more …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-02-04. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Concomitant treatment with irreversible monoamine oxidase inhibitors (MAOIs) - risk of serotonin syndrome; do not initiate for at least 14 days after stopping an irreversible MAOI, and stop venlafaxine at least 7 days before starting one

Side effects

Nausea (very common)
Dry mouth (very common)
Headache (very common)
Hyperhidrosis including night sweats (very common)
Insomnia, dizziness, sedation, constipation (common)
Hypertension and hot flush; fatigue, asthenia (common)

Interactions

Irreversible MAOIs - contraindicated; risk of serotonin syndrome (SPC 4.3)
Alcohol - patients should be advised not to use alcohol (CNS depressant effects, clinical worsening of psychiatric conditions, potential for adverse interaction) (SPC 4.4)

Clinical monograph

How it works

It inhibits reuptake of serotonin and (at higher doses) noradrenaline, increasing their synaptic availability over several weeks.

Prescribing in practice

It can raise blood pressure in a dose-related way — monitor, particularly at higher doses.
Discontinuation effects can be marked because of its short half-life — taper slowly.
Risk of serotonin syndrome with other serotonergic drugs; caution in cardiac disease and in overdose.

Monitoring

Monitor mood and suicidal ideation early; check blood pressure, especially at higher doses.

Counselling the patient

It can take a few weeks to work.
Do not stop suddenly — withdrawal effects can occur.
Report worsening mood or thoughts of self-harm.

Evidence & guidelines

An option for depression where first-line SSRIs are ineffective or unsuitable (NICE NG222), with blood-pressure monitoring.

Reference: NICE CG90 (Depression); MHRA Drug Safety Update 2012; AGS Beers Criteria 2023; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Duloxetine · SNRI Antidepressant

Pathways