HeadMeds gives young people in the United Kingdom general information about medication. HeadMeds does not give you medical advice. Please talk to your Doctor or anyone else who is supporting you about your own situation because everyone is different. Please read more important details about our site.

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Venlafaxine

Return to Venlafaxine overview
  1. Use and Action
  2. Warnings and side effects
  3. Sex, drink, weight and everything else
Taking venlafaxine originalplayicon listing
Taking Venlafaxine
It felt weird having this tablet inside of you...

You can drink alcohol while taking venlafaxine, but it could make you very sleepy

  • You can continue to drink alcohol while taking venlafaxine but having the two together might make you very sleepy and unsteady on your feet.
  • So, during the first few days, it might be best to stop drinking alcohol until you see how the medicine affects you or the side-effects pass.
  • If you want to drink alcohol, remember that you might be very sleepy and make sure you can get home safely.
  • Drinking alcohol every day, or in large amounts, can make your symptoms worse and the venlafaxine will not get the best chance to act.

Do not drive a car or ride a bike just after you start taking venlafaxine.

  • Taking venlafaxine may make you feel sleepy, dizzy and restless, and could affect your eyesight when you start taking it.
  • This could affect you if you drive a car, ride a bike, or do anything else that needs a lot of focus. It might be best to stop doing these things for the first few days, until you know how it affects you.
  • Do not worry - most people drive as normal while taking venlfaxine

Try not to take venlafaxine for the first time just before your exams.

  • Venlafaxine can make you feel restless in the first few weeks that you take it, and you may not be able to easily sit or stand still.
  • It can also disturb your sleep, and your eyesight.
  • You should talk to your doctor about any future exams if you are starting venlafaxine.
  • You might decide together to delay starting it until you have done them.
  • If they are more than a month away, however, you might find that it is better to start venlafaxine to improve your motivation to study.
  • Do not worry - most people do exams as normal while taking venlafaxine.

Venlafaxine is not a banned substance in sport.

  • Taking venlafaxine may affect your concentration to do things like riding a bike, competitive gymnastics, or anything else that needs a lot of focus.
  • You may find it difficult to easily sit or stand still at first.
  • It may also affect your eyesight.
  • It might produce ringing in your ears, or vertigo.
  • It might be best to stop such sports for the first few days, until you know how it affects you.
  • Do not worry - most people do sports as normal while taking venlafaxine.

Venlafaxine may affect your weight.

  • A side-effect of venlafaxine can be weight loss or weight gain.
  • There is not usually a lot of weight gain, but it is very difficult to know how it will affect each person who takes it.
  • Do not take venlafaxine at the same time as weight loss products.
  • Talk to your doctor about this if it worries you.

Venlafaxine may affect your sleep.

  • You can feel drowsy in the first few days of taking venlafaxine. It should, however, get better after the first week or two.
  • You could also, strangely, have difficulty getting to sleep (insomnia), and disturbing dreams or nightmares.
  • If you feel like a zombie, and you’ve been taking it for more than a month, you should go back to the doctor and see what else you could do.

Venlafaxine can give you a dry mouth, and a greater risk of tooth decay.

  • About 10% (1 in 10) people who take venlafaxine get a dry mouth
  • This can increase your risk of tooth decay and having fillings
  • Make sure you brush your teeth well and have regular check-ups while you are on venlafaxine

Let your family and friends know you are taking venlafaxine so they can support you and help you look out for side effects.

  • The side-effects of venlafaxine might put a strain on your friendships and relationships, especially in the first few days of taking it.
  • You might feel restless, overexcited, anxious, or sleepy.
  • These side-effects should get better after a few days.
  • You should then be getting the good effects of venlafaxine, and that may improve your relationships.
  • It might actually be a great idea to choose a good friend to tell about your medicine when you start taking it. (Or - even better - to take a friend with you to the doctor before you start taking the medicine!)
  • They could look at the medicine leaflet, or at this website.
  • They could help you to understand whether the medicine changes your behaviour, or gives you side-effects (sometimes it is hard for us to see it ourselves).

Venlafaxine can have side-effects that might affect your sex life.

The good effects of venlafaxine may, after a while, have a good effect on your sex life as your mood lifts and you become interested in life and relationships again.

Some of the possible negative side effects include:

  • Men might get problems with getting hard (getting an erection) and coming (ejaculating)
  • Men might get a painful erection that lasts for a long time (priapism), and would need to see a doctor for help straight away
  • Women might have some problems with their periods
  • You may have a lower sex drive
  • If you lose or gain weight, or get other physical side-effects like rashes, you may just not feel as sexy as before

These effects should pass after the first couple of weeks. If they do not, and this is a problem for you, go back to the doctor and see what else you could try.

We do not know if venlafaxine affects human fertility

There is nothing to suggest that venlafaxine causes any problems with fertility.

Is it safe to take venlafaxine in pregnancy?

There is no yes or no answer to this question. When deciding whether or not to take venlafaxine during pregnancy it is important to weigh up how necessary venlafaxine is to your health against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are.

Remaining well is particularly important during pregnancy and while caring for a baby. For some women, treatment with venlafaxine in pregnancy may be the best option for both mother and baby.

Please consult the UK Teratology Information Service’s Best Use of Medicines in Pregnancy (Bumps) website for more information, including specific information on venlafaxine in pregnancy.

  • There does not appear to be a link with an increased risk of malformations or having a baby born early
  • It is less clear if there might be a small increase in the risk of miscarriage or heart defects.
  • If venlafaxine is taken after 20 weeks of pregnancy there is in theory a risk of something called “persistent pulmonary hypertension in the newborn” (or PPHN)
  • This may cause breathing problems in the baby. There is not enough research to be able to tell if this happens with venlafaxine or not. If it does occur, it can be treated by your medical team much better if they know about it in advance
  • If you take venlafaxine in the weeks before delivery your baby may have discontinuation symptoms, such as being irritable, crying, shivering, or problems eating and sleeping. These are usually mild, and go away in a few days without treatment

Is it safe to breast feed while taking venlafaxine?

  • Venlafaxine is passed to the baby in small amounts in breast milk, and whilst this can help with any discontinuation effects, side effects have been seen in breastfed babies.
  • Remember that it is important for you to remain well whilst you are bonding with and looking after your baby. For this reason, it may be best to take medicine for your mental health when breastfeeding.
  • You may also need to consider bottle feeding with formula milk if there are any problems with breastfeeding whilst taking medicines.
  • Talk to your doctor or midwife about your feeding options.
  • Make sure that your doctor, nurse, or health visitor checks your baby for any side effects. These can include:
    • Being extra sleepy
    • Having colic
    • Feeding problems
    • Poor weight gain
  • If your baby was premature or has health problems, then you will need to be extra careful about taking medicines whilst breastfeeding. It may be best not to breastfeed if this is the case, however you should discuss this with your doctor.
  • For more information about breastfeeding when taking antidepressants, please see the Breastfeeding Network website.

Venlafaxine can produce a false positive result in some drug tests

  • Venlafaxine can produce a false positive test for phencyclidine (PCP) on a urine drug screen.
  • Talk to your doctor about this if it is a problem for you.