Venlafaxine
NHS information about the medicine venlafaxine, including what it's used for, who can take it, how to take it and side effects.
What venlafaxine is for
Venlafaxine can be used to treat mental health conditions. It's mainly used to treat depression, but is sometimes used to treat anxiety, panic attacks and menopause symptoms such as hot flushes in women with breast cancer.
It's a type of antidepressant called a selective noradrenaline reuptake inhibitor (SNRI).
SNRIs are thought to work by increasing the level of serotonin and noradrenaline (chemicals in the brain that control mood). When the levels are normal, this may reduce stress levels and negative thoughts.
How to take venlafaxine
Venlafaxine usually comes as tablets or capsules that you swallow. How much you need to take and how you take it depends on why you're taking it and what type you're taking.
Your doctor may prescribe a low dose to start with and increase it after 2 to 3 weeks. This reduces the chances of side effects.
If your symptoms do not improve after taking venlafaxine for a while, your doctor may increase your dose further.
When taking venlafaxine:
- check the packet or leaflet to see if your tablets or capsules are "slow-release" (prolonged release)
- take slow-release tablets or capsules once a day – ideally at the same time each day
- take other venlafaxine tablets or capsules twice a day – ideally once in the morning and once in the evening
- swallow tablets and capsules whole with water
- take it with food
You may need to take venlafaxine for a long time. For example, if you're taking it for depression, you'll probably need to continue to take it for several months or more.
Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.
If you miss a dose of venlafaxine
If you forget to take venlafaxine, take it as soon as you remember.
If it's nearly time for your next dose, skip the missed dose and take your next dose at the usual time.
Do not take 2 doses to make up for a missed dose.
If you take too much venlafaxine
Taking an extra dose of venlafaxine can be dangerous.
Side effects of venlafaxine
Like all medicines, venlafaxine can cause side effects, although not everyone gets them.
Most side effects should ease after a couple of weeks as your body gets used to the medicine, but some can last longer.
Common side effects
Common side effects of venlafaxine include:
- headaches
- feeling sick (nausea) and being sick (vomiting)
- feeling dizzy or drowsy (sleepy)
- dry mouth
- diarrhoea or constipation
- sexual problems, such as low sex drive (loss of libido)
- problems sleeping (insomnia)
- weight changes
If you feel dizzy or drowsy after taking venlafaxine, do not drive, ride a bike or use machinery until these symptoms have gone away.
More about side effects
These are not all the side effects of venlafaxine.
For a full list, see the leaflet inside your medicines packet, or search for your medicine leaflet on the electronic medicines compendium website.
You can report any side effects you get on the Yellow Card Scheme website
Who can and cannot take venlafaxine
Most adults can take venlafaxine.
But venlafaxine is not suitable for everyone. For example, it may not be suitable if:
- you've ever had an allergic reaction to venlafaxine or another SNRI antidepressant
- you have diabetes
- you have epilepsy
- you have heart disease
- you have glaucoma
- you have a bleeding disorder (particularly bleeding in the digestive system)
- you've ever had mania (high moods caused by a mental health condition), or someone in your family has
Before taking venlafaxine, tell your doctor if you have any other medical conditions.
Breastfeeding and venlafaxine
Tell your doctor if you're breastfeeding.
Venlafaxine is sometimes used while breastfeeding, but it's best to check because the medicine can pass into your breast milk.
You may be able to take it, if the benefits outweigh the risks. Sometimes your doctor might want to switch you to a different type of antidepressant.
It's possible for breastfed babies to get side effects from venlafaxine, so speak to a healthcare professional or call NHS 111 if you have any concerns about your baby.
Pregnancy and venlafaxine
Tell your doctor if you're pregnant or you get pregnant while taking venlafaxine.
Venlafaxine can be used during pregnancy if needed. Your doctor will talk to you about the risks and benefits of taking it while you're pregnant.
If you need to take venlafaxine while you're pregnant, your doctor will prescribe the lowest possible effective dose.
You may be advised to give birth in hospital so you and your baby can be closely monitored after you've given birth.
Taking venlafaxine with other medicines, food and drink
There are some medicines, herbal remedies and supplements that may not mix well with venlafaxine.
These include:
- anticoagulants, such as warfarin and apixaban
- non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen
- other antidepressants called monoamine oxidase inhibitors (MAOIs), such as moclobemide and selegiline
Do not use the herbal supplement St John's wort when taking venlafaxine.
Before taking venlafaxine, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.
Food, drink and alcohol with venlafaxine
You can eat and drink normally when taking venlaxafine, but it's best not to drink alcohol because it can increase the risk of side effects.
Find out more about your medicine
To find out more about your medicine, you can:
- check the leaflet that comes with it
- search for your medicine leaflet on the electronic medicines compendium website
- speak to a pharmacist or doctor for advice – if you recently started taking it, you can get help with newly prescribed medicines from a pharmacist as part of the New Medicine Service
