Venlafaxine should be used with caution in: liver or kidney disease, heart problems such as previous heart attack, mania (feeling high or over excited) or history of mania, bipolar disorder or aggressive behaviour, fits (epilepsy), eye problems, history of high pressure in the eye (glaucoma), low platelet count and bleeding problems, history of drug abuse, low sodium levels in your blood (hyponatraemia), patients with an intolerance to certain sugars.
It should not be used in: patients who are allergic to venlafaxine or to any of the other ingredients in the medicine, children, adolescents aged under 18 years, serious problems with heart rhythm, moderate or severe heart failure, high blood pressure that is not properly controlled, patients who are taking or have recently taking other antidepressant drugs known as monoamine oxidase inhibitors (MAOIs) which are also used to treat Parkinson's disease, pregnancy and breastfeeding.
Also see list of precautions and interactions
Store below 25ºC in a dry place.
Venlafaxine is used to treat depression.
It is a serotonin noradrenaline reuptake inhibitor (SNRI), sometimes known as an antidepressant.
It is used to treat the symptoms of depression. Patients who are depressed are thought to have lower levels of the chemicals noradrenaline and serotonin in their brain. Venlafaxine is thought to help people who are feeling depressed by increasing the levels of these substances in the brain.
In general this drug is used to treat patients who are feeling depressed.
Benefits of being on this drug can include relief from the symptoms of depression and feeling less anxious.
Listed below are the typical uses of venlafaxine.
On occasion your doctor may prescribe this medicine to treat a condition not on the above list. Such conditions are listed below.
HOW TO USE/TAKE
How often do I take it?
- Take this medication orally usually twice daily in the morning and evening, with food. Swallow the tablets whole with a drink of water, do not crush or chew the tablets. Venlafaxine is also available as a slow release capsule which means it releases the drug more slowly into your body and usually only needs to be taken once a day.
- Use this medication regularly in order to get the most benefit from it.
- Remember to use it at the same time each day - unless specifically told otherwise by your doctor.
- It may take up to a few weeks or more before the full benefit of this drug takes effect.
- Certain medical conditions may require different dosage instructions as directed by your doctor.
- Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.
Do I need to avoid anything?
- Venlafaxine may cause confusion, dizziness and blurred eyesight. If you develop any of these symptoms then do not drive or operate machinery. Consult your doctor or pharmacist for more details.
When can I stop?
- It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop. If venlafaxine is stopped suddenly or the dose is reduced too quickly, some patients experience side effects. If your doctor thinks that you no longer need to take venlafaxine then your dose will be reduced slowly before stopping treatment altogether.
VENLAFAXINE SIDE EFFECTS
- Feeling sick or being sick
- Unusual tiredness or weakness
- Sweating including night sweats
- Dry mouth (may be associated with an increased risk of tooth decay so extra care should be taken with dental hygiene)
- Difficulty sleeping
- Feeling nervous
- Change in sexual function (abnormal ejaculation in men, lack of orgasm, impotence)
- Change in appetite or bowel habits
- Abdominal discomfort
- Weight loss or gain
- Chills and fever
- Increased blood pressure
- Feeling agitated
- Feeling confused
- Abnormal dreams
- Sore muscles or painful joints
- Increased levels of cholesterol in the blood (hypercholesterolaemia)
- Skin rash
- Pins and needles
- Feeling the need to go to the toilet more often than usual
- Menstruation (period) changes in women
- Blurred eyesight
- Ringing in the ears (tinnitus)
- Difficulty breathing (dyspnoea)
Further information about other side effects can be found on the patient information leaflet.
If any of these persist or you consider them severe then inform your doctor or pharmacist.
Tell your doctor immediately or go to you local hospital casualty department if you develop any of the following symptoms:
- Thoughts of suicide
- Feelings of restlessness and unable to keep still
- Feeling high or over-excited, drowsiness, prolonged fast eye movements, clumsiness, restlessness, feeling drunk, sweating and stiff muscles (these are symptoms of serotonergic syndrome)
- Jerky muscle movements which you can't control, high temperature with stiff muscles, confusion or agitation and sweating (this may be a sign of a rare condition called neuroleptic malignant syndrome)
- Swollen face or tongue, shortness of breath or difficulty breathing and skin rashes (this may be a sign of a serious allergic reaction)
- Fits (seizures)
- Severe muscle tenderness, weakness, stiffness (particularly if you pass dark water or urine when going to the toilet)
- Black tarry stools (faeces) which may be a sign of internal bleeding
- Severe pain in the stomach area or back
- Frequent or unusual bruising and bleeding such as nosebleeds
- Fast or irregular heartbeat
- Flushing or fainting
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.
Before taking venlafaxine, tell your doctor or pharmacist if you are allergic to it; or to other SNRIs; or if you have any other allergies.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: an allergy to venlafaxine or to any of the other ingredients in the medicine, serious problems with heart rhythm, moderate or severe heart failure, high blood pressure that is not properly controlled, are taking or have recently taking other antidepressant drugs known as monoamine oxidase inhibitors (MAOIs) which are also used to treat Parkinson's disease, are pregnant or breast feeding.
Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: liver or kidney disease, heart problems such as previous heart attack, mania (feeling high or over excited) or history of mania, bipolar disorder or aggressive behaviour, fits (epilepsy), eye problems, history of high pressure in the eye (glaucoma), low platelet count and bleeding problems, history of drug abuse, low sodium levels in your blood (hyponatraemia), an intolerance to certain sugars.
Before having surgery, tell your doctor or dentist that you are taking this medication.
Does alcohol intake affect this drug?
- You should not drink alcohol whilst taking venlafaxine.
The elderly: venlafaxine can be used in the elderly but should be used with caution as older patients may have kidney problems and require a lower dose of venlafaxine. Elderly patients are also more likely to feel dizzy or unsteady when taking venlafaxine.
Pregnancy and breastfeeding - please ensure you read the detailed information below
The safety of venlafaxine has not been established during pregnancy. Ask your doctor or pharmacist if you have any doubts or questions about this.
It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.
If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.
Venlafaxine is not safe to take if you are breastfeeding.
It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.
If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.
This drug should not be used with the following medications because very serious, possibly fatal interactions may occur:
- Monoamine oxidase inhibitors (MAOIs) used to treat depression and Parkinson's disease. (If you are taking a MAOI, venlafaxine should not be started until at least 14 days after stopping treatment with an MAOI. MAOI treatment should not be started until at least 7 days after stopping venlafaxine).
If you are currently using any of these medications, tell your doctor or pharmacist before starting venlafaxine.
Before using this medication, tell your doctor or pharmacist of all prescription and non-prescription/herbal products you may use, especially of:
- Drugs used to treat depression (such as selective serotonin reuptake inhibitors [SSRIs], lithium and tricyclic antidepressants)
- Cimetidine (a stomach drug)
- Migraine drugs called triptans
- Warfarin (a blood thinner)
- Drugs for schizophrenia (such as haloperidol, clozapine)
- Regular aspirin
- Drugs for AIDS or HIV infection
- Medicines to help you lose weight
- Ketoconazole (for fungal infections)
- Erythromycin (an antibiotic)
- Linelozid (an antibiotic)
- Haloperidol or risperidone (used for psychiatric illness)
- Metoprolol (used for high blood pressure and heart problems)
- Tramadol (a painkiller)
- Medicines containing tryptophan
- St John's Wort
- You are having electroconvulsive therapy (ECT) for depression
This information does not contain all possible interactions. Therefore, before using venlafaxine tell your doctor or pharmacist of all the products you use.
If you take too many tablets contact your doctor or casualty department of your local hospital immediately, even if you feel well. Remember to take the packet of tablets with you, even if it is empty, when you go to the doctor or hospital
If you think you, or someone you care for, might have accidentally taken more than the recommended dose of venlafaxine or intentional overdose is suspected, contact your local hospital, GP or if in the UK call NHS Direct on 0845 4647.
If you miss a dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
If you are taking slow release venlafaxine you can take it up to 12 hours after you usually take it and then take your next capsule at the usual time. If it is more than 12 hours after your last dose then you should miss the dose altogether and take your next capsule at the usual time.