Venlafaxine

About venlafaxine

What is venlafaxine used for?

Venlafaxine belongs to a group of medicines known as serotonin and noradrenaline reuptake inhibitor (SNRI) antidepressants. It is used for the treatment of depression and generalised anxiety disorder (GAD).

Venlafaxine works by regulating the levels of chemicals in the brain, called serotonin and noradrenaline; this eases the symptoms of depression and anxiety in some people.

Depression can develop for no apparent reason, or it may be triggered by a life event such as a relationship problem, bereavement, or illness. People with depression have a consistently low mood and other symptoms severe enough to interfere with normal day-to-day activities.

Side effects of venlafaxine

The most common side effects of venlafaxine are:

• Feeling sick.

• Headache.

• Feeling dizzy, tired or sleepy.

• Dry mouth.

• Constipation.

• Sweating.

• Trouble sleeping.

You will find a full list in the manufacturer's information leaflet supplied with your medicine.

The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

How to manage venlafaxine side effects

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

Who should not take venlafaxine?

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking venlafaxine it is important that your doctor knows:

• If you are pregnant or breastfeeding.

• If you have a heart condition.

• If you have a problem with the way your liver works, or a problem with the way your kidneys work.

• If you have epilepsy.

• If you have high blood sugar levels (diabetes mellitus).

• If you or any close family members have ever had abnormally 'high' moods.

• If you have increased pressure in your eyes, a condition called glaucoma.

• If you have ever had a bleeding disorder.

• If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

• If you have ever had an allergic reaction to a medicine.

How to take venlafaxine

• Read the manufacturer's printed information leaflet from inside the pack. It will give you more information about venlafaxine and it will provide you with a full list of the side effects which you may experience from taking it.

• Take venlafaxine exactly as your doctor tells you to. Depending upon the brand of tablet/capsule that you are prescribed, you will be asked to take either one or two doses a day.

• Try to take your doses at the same time(s) of day each day, as this will help you to remember to take them. Have a drink of water to help you swallow the tablet/capsule.

• If you have been supplied with a modified-release form of venlafaxine (these have the letters 'XL' after the brand name), take the tablet/capsule just after a meal.

  • You should swallow the tablets/capsules whole - do not chew or crush them. Modified-release tablets and capsules release venlafaxine slowly over 24 hours to give a longer action.

• If you forget to take a dose, take it as soon as you remember. If when you remember, it is nearly time for your next dose then leave out the missed dose and take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

• Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress.

• You may feel that venlafaxine is not working for you straightaway. It can take a week or two after starting this treatment before the effect builds up, and up to four weeks before you feel the full benefit. Do not stop taking it after a week or so, thinking it is not helping.

• While you are taking venlafaxine (and especially if you are depressed), you may have distressing thoughts, and think about harming yourself or ending your life. If this happens, it is very important that you tell your doctor about it straightaway.

• There are several types of antidepressants - each type works in a slightly different way and can have different side effects. If you find that venlafaxine does not suit you then let your doctor know, as another antidepressant may be found that does.

• Some people who take venlafaxine find that their skin becomes more sensitive to sunlight than usual. Try to avoid strong sunlight until you know how your skin reacts, or use a sun cream with a high sun protection factor. Do not use sunbeds.

• If you have diabetes you may need to check your blood sugar (glucose) more frequently. This is because venlafaxine can alter the levels of sugar in your blood. Your doctor will advise you about this.

• Ask your doctor for advice before drinking alcohol. Your doctor may recommend that you do not drink alcohol during your treatment with venlafaxine. Alcohol may cause more drowsiness and may worsen symptoms of depression or anxiety.

• If you buy any medicines, always check with a pharmacist that they are suitable for you to take. There is an increased risk of side effects when venlafaxine is taken alongside some anti-inflammatory painkillers which can be bought from pharmacies.

• If you are due to have any medical treatment, tell the person carrying out the treatment which medicines you are taking.

• Continue to take venlafaxine until your doctor tells you otherwise. Your doctor will ask you to carry on taking venlafaxine even after you feel better. This is to help stop your symptoms from returning.

  • Stopping treatment suddenly can cause problems and your doctor will want you to reduce your dose gradually when this becomes necessary.

How to store venlafaxine

• Keep all medicines out of the reach and sight of children.

• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Frequently asked questions

Why is venlafaxine called the happy pill?

Venlafaxine is sometimes nicknamed the “happy pill” as it helps lift mood in depression and anxiety, but it’s not an instant fix and usually takes weeks to work.

Does venlafaxine cause weight gain?

Weight gain isn't usually a common side effect, but taking venlafaxine can cause your weight to fluctuate. Speak to your doctor if there are any concerns.

Should I take venlafaxine in the morning or at night?

Venlafaxine can be taken either in the morning or at night, depending on how it affects you. Some people feel more alert after taking it, so morning might be best, while others find it makes them drowsy and prefer to take it at night. Make sure to take it at the same time each day to keep levels steady.