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Antidepressant (SNRI - serotonin-noradrenaline reuptake inhibitor)

Venlafaxine: uses, side effects & precautions

Also known as Effexor, Effexor XR.

Deze informatie is uitsluitend bedoeld als algemene richtlijn en vormt geen medisch advies. Raadpleeg altijd een gekwalificeerde zorgprofessional voor persoonlijke medische vragen. Bel in geval van nood uw lokale alarmnummer.

What it is used for

  • Depression
  • Generalised anxiety disorder
  • Panic disorder
  • Social anxiety disorder

How it works

Venlafaxine increases the levels of two chemical messengers, serotonin and noradrenaline, in the brain by reducing their reuptake. This is thought to help improve mood and reduce anxiety over time.

How it is taken

Usually available as standard tablets and as longer-acting (extended-release) capsules or tablets. It is taken by mouth. Take it exactly as your doctor or pharmacist directs and follow the label; the extended-release form is usually swallowed whole. Do not stop suddenly, as withdrawal effects can be marked.

No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.

Common side effects

  • Nausea
  • Dry mouth
  • Sweating
  • Headache
  • Dizziness
  • Trouble sleeping or drowsiness
  • Constipation
  • Reduced appetite
  • Sexual difficulties
  • Feeling jittery

Serious effects — get help

  • New or worsening suicidal thoughts, especially early on (seek urgent help)
  • Raised blood pressure
  • Serotonin syndrome: agitation, fever, muscle twitching, confusion
  • Heart-rhythm changes
  • Severe allergic reaction
  • Unusual bleeding
  • Seizures
  • Signs of low sodium: confusion, weakness
  • Severe withdrawal symptoms if stopped abruptly

If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.

Interactions to watch

  • MAOI antidepressants (must not be combined)
  • Other serotonin-raising medicines (triptans, tramadol, St John's Wort)
  • Blood thinners, aspirin and NSAIDs (bleeding risk)
  • Other medicines that raise blood pressure
  • Medicines affecting heart rhythm
  • Alcohol

Who should take care

  • Can raise blood pressure, which may be monitored during treatment
  • Tell your clinician if you are pregnant, planning pregnancy or breastfeeding
  • Use with caution with heart disease, high blood pressure, glaucoma, epilepsy or bleeding disorders
  • Withdrawal effects can be more pronounced; never stop abruptly
  • Closer monitoring may be needed for people under 25

Frequently asked questions

Why can stopping venlafaxine be difficult?
Venlafaxine leaves the body fairly quickly, so missing doses or stopping suddenly can cause withdrawal effects like dizziness, electric-shock sensations, nausea and irritability. Always taper slowly with your clinician's guidance.
Does it affect blood pressure?
It can raise blood pressure, especially at higher amounts. Your clinician may check your blood pressure during treatment.
How long until I notice benefit?
Mood and anxiety usually improve over 4-6 weeks. Continue as prescribed and review with your clinician.
What is the difference between the regular and XR forms?
The extended-release (XR) form releases medicine slowly over the day, often allowing once-daily dosing with steadier levels. Take whichever form your clinician prescribed, exactly as directed.
Is Venlafaxine safe to take?
For most people it is safe when taken exactly as a doctor or pharmacist advises and as printed on the label. Tell your clinician about your other medicines and health conditions, and seek urgent care for any serious reaction.

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