Venlafaxine

Sounds like 'ven-la-FAX-een'

Easy-to-read medicine information about venlafaxine – what it is, how to take venlafaxine safely and possible side effects.

Type of medicineAlso called
  • Antidepressant
  • Belongs to a group of medicines known as serotonin-noradrenaline reuptake inhibitors (SNRIs)
  • Arrow-Venlafaxine XR ®
  • Efexor-XR ®


What is venlafaxine?

  • Venlafaxine is used to treat depression, anxiety disorder or panic disorder.
  • It works by regulating two chemicals in the brain called serotonin and noradrenaline and in this way improves mood and helps to ease anxiety.
  • It is one of a group of medicines known as serotonin-noradrenaline reuptake inhibitors (SNRIs).
  • Venlafaxine is available as tablets and capsules.

Dose

  • The dose of venlafaxine will be different for different people. Your doctor will usually start you on a low dose and increase this slowly. This allows your body to get used to the medicine and reduces unwanted side effects.
  • The usual dose for depression is 75 mg to 225 mg a day.
  • The usual dose for anxiety is 75 mg a day.
  • Always take your venlafaxine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much venlafaxine to take, how often to take it, and any special instructions.

How to take venlafaxine

  • Take venlafaxine once a day, at the same time each day, either in the morning OR in the evening.
  • It is best to take venlafaxine with or after food. 
  • Take your venlafaxine with at least half a glass of water whilst sitting or standing. This is to make sure that it reaches the stomach and does not stick in your throat.
  • Swallow your venlafaxine capsule or tablet whole – do not crush or chew. This will release all the medicine at once.
  • Limit or avoid drinking alcohol while you are taking venlafaxine. It will make you feel more sleepy or drowsy.
  • If you forget to take your dose of venlafaxine, and if it is less than 12 hours until your next dose, wait until the next day and take your normal dose then. Do not take double the dose. Otherwise, take it as soon as you remember, and then go back to taking as you would normally.
  • Keep taking your venlafaxine every day. It may take a few weeks before you experience the full benefits of venlafaxine.
  • Do not stop taking venlafaxine suddenly; speak to your doctor or nurse before stopping.

Possible side effects

Like all medicines, venlafaxine can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effectsWhat should I do?
  • Feeling sick (nausea) or vomiting
  • Stomach upset
  • Try taking venlafaxine after food.
  • Tell your doctor if troublesome
  • Feeling sleepy, drowsy, or tired
  • Try taking venlafaxine in the evening
  • Be careful when driving or using tools until you know how this medicine affects you
  • Tell your doctor if troublesome
  • Headache
  • Dry mouth
  • Increased sweating
  • Weight changes


  • These are quite common when you first start taking venlafaxine and usually go away with time
  • Tell your doctor if troublesome
  • Signs of an allergic reaction such as difficulty breathing, shortness of breath, skin rash, or itching
  • Tell your doctor immediately or ring HealthLine 0800 611 116
  • Signs of serotonin syndrome such as feeling agitated and restless, heavy sweating, shivering, fast heart rate or irregular heart beat, headache, diarrhoea and rigid or twitching muscles
  • You are at increased risk of serotonin syndrome if you recently started taking venlafaxine or recently increased the dose
  • Tell your doctor immediately or ring HealthLine 0800 611 116

Interactions

Venlafaxine interacts with a number of important medications and herbal supplements (such as St. John's wort) so check with your doctor or pharmacist.

Learn more

The following is links provide further information on venlafaxine.

Medsafe consumer information sheets:
Arrow-Venlafaxine XR 
Efexor XR

New Zealand Formulary Patient Information:
Venlafaxine

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft, Health Navigator