Venlafaxine

VENLAFAXINE

Medicine Information

Venlafaxine is one of a group of antidepressants called serotonin and noradrenaline reuptake inhibitors, or SNRIs. These medicines are thought to work by increasing the levels of mood-enhancing chemicals called serotonin and noradrenaline in the brain.

You may see an improvement in your symptoms after a week although it usually takes between 4 and 6 weeks before you feel the full benefits. That’s because it takes around a week for venlafaxine levels to build up in your body, and then a few weeks longer for your body to adapt and get used to it.

Do not stop taking venlafaxine just because you feel it is not helping your symptoms. Give the medicine at least 6 weeks to work.

Venlafaxine can make you feel less hungry than usual, so you may lose weight when you start taking it. Some people might find they gain weight.

If you start to have problems with your weight while taking venlafaxine, talk to your doctor or pharmacist.

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

Some of the possible negative effects include:

  • men might have problems with getting an erection, or with ejaculating
  • women might have some vaginal bleeding
  • both men and women might find they don’t reach orgasm the same way as before
  • you may have a lower sex drive

Sexual side effects usually pass after the first couple of weeks. However, very rarely, they can be long lasting and may not get better even after stopping the medicine.

If these happen and are a problem for you, go back to your doctor to see if there’s another treatment you can try.

Venlafaxine will not affect contraception including the combined pill or emergency contraception.

Some people can’t concentrate properly while they’re taking venlafaxine. It might be best to stop driving and cycling for the first few days of treatment until you know how this medicine makes you feel.

You can drink alcohol while taking venlafaxine but it may make you feel sleepy. It might be best to stop drinking alcohol during the first few days of treatment until you see how this medicine affects you.

Cannabis with venlafaxine can give you a fast heartbeat. Cannabis can also make drowsiness worse with venlafaxine, especially in people who have just started taking it.

Methadone can make sleepiness worse with venlafaxine. It can be potentially dangerous to take venlafaxine with:

  • stimulants like MDMA (ecstasy) or cocaine
  • hallucinogens like LSD
  • novel psychoactive substances (which used to be known as legal highs) like mephedrone

Antidepressants like venlafaxine help to jump start your mood so you feel better. You may notice that you sleep better and get on with people more easily because you’re less anxious. You will hopefully take little things that used to worry you in your stride.

Venlafaxine won’t change your personality or make you feel really happy. It will simply help you feel like yourself again.

Don’t expect to feel better overnight, though. Some people feel worse during the first few weeks of treatment before they begin to feel better.

Once you’re feeling better it’s likely that you will continue to take venlafaxine for several more months. Most doctors recommend that you take antidepressants for 6 months to 1 year after you no longer feel depressed. Stopping before that time can make depression come back.

For most people, venlafaxine is safe to take for a long time.

A few people may get sexual side effects, such as problems getting an erection or a lower sex drive. In some cases these can continue even after stopping the medicine. Speak to your doctor if you are worried.

Otherwise there don’t seem to be any lasting harmful effects from taking venlafaxine for many months and years.

If you’ve been feeling better for 6 months or more, your doctor may suggest coming off venlafaxine.

Your doctor will probably recommend reducing your dose gradually over several weeks – or longer, if you have been taking venlafaxine for a long time.

This is to help prevent any extra side effects you might get as a reaction to coming off the medicine. These include:

  • dizziness
  • feeling sick
  • numbness or tingling in the hands or feet
  • trouble sleeping
  • feeling agitated or anxious
  • headaches
  • shaking

Venlafaxine isn’t any better or worse than other antidepressants. However, sometimes people respond better to one antidepressant than to another. If you aren’t feeling any better after 6 weeks, talk to your doctor.

Antidepressants, including venlafaxine, are just one of several approaches to treating depression or anxiety.

Other potential treatments for depression include:

Other potential treatments for anxiety include:

Choosing a treatment that’s most suitable for you depends on:

  • how long you’ve had depression or anxiety and your symptoms
  • whether previous treatment has worked
  • how likely you are to stick with your treatment
  • the potential side effects
  • your preferences and priorities

If you’re interested in any of these treatments, talk to your doctor.

There’s no firm evidence to suggest that taking venlafaxine will reduce fertility in men, but it may interfere with the menstrual cycle in women.

Speak to a pharmacist or your doctor if you’re trying to get pregnant. They may want to review your treatment.

You can eat and drink normally while taking venlafaxine.