Keep your regular appointments with your doctor. This is so your doctor can check on your progress.
It may take a week or two after starting the treatment before you begin to feel the benefit. Do not stop taking venlafaxine, thinking it is not helping.
Tell your doctor if you experience any troublesome side-effects.
|Type of medicine||A serotonin and noradrenaline reuptake inhibitor (SNRI) antidepressant|
|Used for||Adults with depression or generalised anxiety disorder|
|Also called (UK)||Alventa® XL; Depefex® XL; Efexor® XL; Politid® XL; Rodomel® XL; Sunveniz® XL; Tonpular® XL; Venaxx® XL; Vencarm® XL; Venlablue® XL; Venladex® XL; Venlalic® XL; Venlasov® XL; Vensir® XL; ViePax® XL|
|Also called (USA)||Effexor® XR|
|Available as||Tablets, modified-release tablets and modified-release capsules|
Venlafaxine belongs to a group of medicines known as serotonin and noradrenaline reuptake inhibitor (SNRI) antidepressants. It is prescribed for the treatment of depression, and also for the treatment of generalised anxiety disorder (GAD).
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. Although it is not fully understood what causes depression, an imbalance of naturally occurring chemicals in the brain is thought to be a factor. Venlafaxine works by regulating the levels of chemicals in the brain, called serotonin and noradrenaline; this eases the symptoms of depression in some people.
Although venlafaxine is often used to treat depression, it can also ease the symptoms of GAD. This is a condition where anxiety is a major symptom. Venlafaxine can help ease the anxiety even if you are not depressed.
Before taking 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 breast-feeding.
- 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
- Before you start the treatment, 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.
- 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.
Can venlafaxine cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with venlafaxine. 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.
|Very common venlafaxine side-effects (these affect more than 1 in 10 people)||What can I do if I experience this?|
|Headache||Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know|
|Feeling dizzy, tired or sleepy||Do not drive and do not use tools or machines until you feel better. Do not drink alcohol|
|Dry mouth||Try chewing sugar-free gum or sucking sugar-free sweets|
|Constipation||Try to eat a well-balanced diet containing plenty of fibre and drink plenty of water each day|
|Feeling sick||Stick to simple foods. Try taking your doses after meals if you are not already doing so|
|Sweating||Take care not to become overheated during exercise or hot weather|
|Common venlafaxine side-effects (these affect less than 1 in 10 people)||What can I do if I experience this?|
|Diarrhoea||Drink plenty of water to replace lost fluids|
|Other side-effects include weight changes, sleeping problems, movement problems, tingling feelings, feeling nervous or confused, hearing problems, eyesight problems, lack of appetite, chills, yawning, hot flushes, difficulties having sex, difficulty passing urine, increased cholesterol, menstrual problems, a fast heartbeat, a rash or itchy skin||If any of these become troublesome, speak with your doctor for advice|
If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.
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
Never take more than the prescribed dose. Tricyclic antidepressants can be dangerous in overdose. If you suspect that you or someone else might have taken an overdose, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Further reading and references
Manufacturer's PIL, Efexor® XL 75 mg, 150 mg and 225 mg Capsules; Pfizer Limited, The electronic Medicines Compendium. Dated May 2016.
British National Formulary 74th Edition (Sep 2017); British Medical Association and Royal Pharmaceutical Society of Great Britain, London.