Venlafaxine at a glance
Medicine class
SNRI antidepressant.
Main licensed uses
Depression and prevention of recurrent depressive episodes; selected prolonged-release products are also licensed for generalised anxiety, social anxiety and panic disorders.
Administration
Take with food. Swallow prolonged-release tablets or capsules whole.
Stopping treatment
Do not stop suddenly without prescriber advice because withdrawal symptoms are common and can be severe or prolonged.
What is Venlafaxine used for?
UK licensing differs by formulation.
Immediate-release tablets and oral solutions are licensed for major depressive episodes and preventing recurrence.
Selected prolonged-release tablets and capsules are additionally licensed for generalised anxiety disorder, social anxiety disorder and panic disorder with or without agoraphobia.
How does Venlafaxine work?
Venlafaxine and its active metabolite reduce serotonin and noradrenaline reuptake in the central nervous system, increasing signalling involving these neurotransmitters. Venlafaxine also has a weaker effect on dopamine reuptake.
Venlafaxine preparations and strengths
Capsule
Route: Oral
Strengths: 37.5 mg, 75 mg, 150 mg
Modified-release capsule
Route: Oral
Strengths: 37.5 mg, 75 mg, 150 mg, 225 mg, 300 mg
How to take Venlafaxine
Follow the label for the supplied formulation because immediate-release and prolonged-release products are administered differently.
Take venlafaxine with food.
Swallow prolonged-release tablets and capsules whole with fluid; do not divide, crush, chew or dissolve them.
Measure oral solution with the supplied device, not a household spoon.
Healthcare professionals may administer oral solutions through suitable nasogastric or PEG tubes according to the product instructions.
Venlafaxine side effects
Common or expected effects
- Nausea or vomiting
- Dry mouth
- Headache
- Sweating, including night sweats
- Dizziness, sleepiness or difficulty sleeping
- Constipation or diarrhoea
- Reduced appetite or weight change
- Sexual difficulties affecting libido, orgasm, erection or ejaculation
Get urgent medical advice
- Suicidal thoughts, severe worsening of mood or unusual behavioural change
- Possible serotonin syndrome
- Severe allergic reaction with swelling or breathing difficulty
- Seizure
- Very high blood pressure, fainting or a serious abnormal heartbeat
- Severe eye pain or sudden visual disturbance
- Unusual or severe bleeding
- Confusion, marked weakness or seizures that could indicate low blood sodium
Venlafaxine in pregnancy
Venlafaxine can be used during pregnancy when recommended after weighing the benefits of maternal mental health treatment against possible risks. Available evidence does not show harm to fetal development, but late-pregnancy exposure can cause short-term newborn withdrawal or adaptation symptoms. Do not stop suddenly; discuss treatment with the prescriber, midwife or mental-health team.
Venlafaxine while breastfeeding
Venlafaxine and its active metabolite enter breast milk. It may be used cautiously after individual assessment, although alternatives may be preferred when starting treatment. Monitor a full-term healthy infant for unusual drowsiness or agitation, poor feeding, gastrointestinal symptoms and inadequate weight gain; seek specialist advice for premature or unwell infants.
Venlafaxine interactions
Check prescribed, non-prescription and herbal medicines before combining them with venlafaxine.
Monoamine oxidase inhibitors (MAOIs), including irreversible MAOIs, moclobemide, linezolid and methylene blue
Combinations can cause serious serotonin toxicity. Irreversible MAOIs are contraindicated, and switching requires carefully managed separation.
Other serotonergic medicines, including other antidepressants, triptans, lithium and some opioids
May increase the risk of serotonin syndrome and requires clinical review and monitoring.
St John’s wort and tryptophan supplements
May increase serotonergic adverse effects; do not add them without professional advice.
Common questions about Venlafaxine
Answers are fully visible for fast scanning and source review.
How long does venlafaxine take to work?
Benefits are not immediate. Some change may occur within the first few weeks, but the full effect can take longer. Seek prescriber review if symptoms worsen or improvement is not emerging as expected.
Is venlafaxine addictive?
It is not considered addictive, but physical withdrawal symptoms can occur if it is missed, reduced or stopped, especially abruptly.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.