VENLAFAXINE (‘Efexor’)
Ven – la – fax – een
Why have I been prescribed venlafaxine?
Venlafaxine is used to treat depression. Depression is a common condition. It is different from the normal “ups and downs”
of everyday life. People with depression may feel sad most of the time and cannot see an end to their sadness. Tiredness
and poor sleep are very common, and so are changes in appetite. Many people also find that they simply cannot enjoy any
of life’s pleasures.
Depression can be treated in many ways. Other “talking” therapies are also effective in depression. Antidepressants can
generally be relied upon to relieve the symptoms of depression in most people. Venlafaxine can also be useful in helping to
manage other conditions, such as anxiety and obsessive-compulsive disorder.
What exactly is venlafaxine?
Venlafaxine is an antidepressant. It is not a tranquilliser or sleeping tablet. It is a relatively new kind of antidepressant and
has been in widespread use for a few years. The trade or brand name of venlafaxine is ‘Efexor’.Efexor XL’ is still
venlafaxine. The difference is that they are capsules instead of tablets and are “slow release”. This means they can be
taken once a day instead of twice a day, and you may get fewer side effects.
Is venlafaxine safe to take?
It is usually safe to have venlafaxine regularly as prescribed by your doctor, but it doesn’t suit everyone. Let your doctor
know if any of the following apply to you, as extra care may be needed:
a) if you have epilepsy or glaucoma, or suffer from heart, liver or kidney trouble;
b) if you are taking any other medication. This includes medicine from your pharmacist, such as antihistamines, St. John’s
wort or cimetidine (‘Tagamet’);
c) if you are pregnant, breast feeding, or wish to become pregnant.
What is the usual dose of venlafaxine?
The starting dose of venlafaxine is 75mg a day. The usual dose is between 75mg and 150mg a day. The maximum dose of
venlafaxine is 375mg a day. If you are taking the slow release capsules (Efexor XL), the maximum dose is 225mg a day.
How should I take my venlafaxine?
Look at the label on your medicine; it should have all the necessary instructions on it. Follow this advice carefully. If you
have any questions, speak to your pharmacist, doctor or nurse. Most medicines are now dispensed with an information
leaflet for you to read.
What should I do if I miss a dose?
Never change your dose without checking with your doctor. If you forget a dose, take it as soon as you remember, as long
as it is within a few hours of the usual time.
When I feel better, can I stop taking venlafaxine?
No. If you stop taking venlafaxine, your original symptoms may return. To reduce your chances of becoming depressed
again, you may need to take your antidepressant for at least 6 months after you feel better, and sometimes longer. This is
not thought to be harmful. You should decide with your doctor when you can come off it.
Is venlafaxine addictive?
Venlafaxine is not addictive, but needs to be treated with respect. Some people do get some “discontinuation” effects if
they stop their venlafaxine suddenly, or rarely by missing a few doses. These effects include anxiety, dizziness, feeling sick
and not being able to sleep. Some people feel confused and “out of sorts”. These symptoms are less severe if you come
off your venlafaxine slowly. It is best to discuss this with your pharmacist, doctor or nurse.
What will happen to me when I start taking venlafaxine?
All antidepressants work slowly. People tend to feel better over a period of weeks rather than days. Different symptoms
may get better at different times. Most people find that they feel noticeably better after about two or three weeks. However,
the full effect of antidepressants is usually felt only after about four to six weeks. It is very important to continue to take
antidepressants so that the full effects can be felt. Speak to your pharmacist, doctor or nurse if you have any questions
about this.
Unfortunately, you might get some side effects before you start to feel any better. Most side effects should go away after a
few weeks. Look at the table over the page. It tells you what to do if you get any side effects. Not everyone will get the side
effects shown. There are many other possible side effects. Ask your pharmacist, doctor or nurse if you are worried about
anything else that you think might be a side effect.
Side effect What is it? What should I do if it happens to me?
COMMON
ANXIETY Feeling nervous This should go with time. If you are worried, contact your doctor.
CONSTIPATION Feeling "bunged up" inside. You can't
pass a motion or stool.
Eat more fibre e.g. bran, fruit and vegetables. Do more walking. Make
sure you drink plenty of fluid. A mild laxative from a pharmacy might
help.
DIARRHOEA The “runs”, or loose stools This should wear off fairly quickly. If it becomes a problem, contact
your pharmacist or doctor.
DIZZINESS Feeling light headed. This should wear off with time. If it is bad, contact your doctor.
DROWSINESS Feeling sleepy or sluggish. It can last
for a few hours after taking your dose
Don’t drive or use machinery. Ask your doctor if you can take your
venlafaxine at a different time. If you are taking the tablets twice a
day, it may help to change to the slow release capsules.
HEADACHE Your head is pounding and painful. It should be safe to take aspirin or paracetamol.
INSOMNIA Not able to sleep at night If you are worried, contact your doctor.
NAUSEA Feeling sick. Taking each dose with or after food may help. If it is bad, contact your
doctor. Changing to the slow release capsules may help.
SWEATING Sweating more than normal,
especially at night.
If it is bad, see your doctor.
FAIRLY COMMON
SEXUAL
DYSFUNCTION
Lack of libido or no interest in sex.
Inability to maintain an erection or
have an orgasm.
Discuss this with your doctor when you next meet.
UNCOMMON
BLURRED
VISION
Things look fuzzy and you can’t focus
properly.
Things look fuzzy and you can’t focus properly. See your doctor if you
are worried. You won’t need glasses.
HYPERTENSION High blood pressure This usually only happens if you are taking more than 200mg a day.
HYPOTENSION A low blood pressure. You may feel
faint when you stand up.
Try not to stand up too quickly. If you feel dizzy, don’t drive. This
dizziness is not dangerous
RASH or
URTICARIA
Blotches everywhere on your skin. Stop taking venlafaxine and contact your doctor now.
TREMOR Feeling shaky Contact your doctor now.
VOMITING Being sick If it is bad, contact your doctor. Changing to the slow release
capsules may help.
What about alcohol?
It is officially recommended that people taking venlafaxine should not drink alcohol. This is because both venlafaxine and
alcohol can cause drowsiness. If the two are taken at the same time, severe drowsiness can result. This can lead to falls or
accidents. As well as this, drinking alcohol often makes depression worse. Excessive drinking is especially likely to do this.
Once people are used to taking medication, they can sometimes drink alcohol in small amounts without any harm. Avoid
alcohol altogether for the first one or two months. After this, if you want a drink, try a glass of your normal drink and see
how you feel. If this doesn’t make you feel drowsy, then it is probably OK to drink small amounts. It pays to be very cautious
because alcohol affects people in different ways, especially when they are taking medication.
Don’t stop taking your medication because you fancy a drink at the weekend. If you do drink alcohol, drink only small
amounts. Never drink any alcohol and drive while on venlafaxine. Discuss any concerns you may have with your doctor or
pharmacist.
Remember, leaflets like this can only describe some of the effects of medication. You may find other
books or leaflets also useful. If you have access to the internet you may find a lot of information
there as well, but be careful, as internet based information is not always accurate.
2001 United Kingdom Psychiatric Pharmacy Group www.ukppg.org.uk
This leaflet is to help you understand about your medicine. It is not an official manufacturer's Patient Information Leaflet.
For more information call the UKPPG National Telephone Helpline, 11am to 5pm, Monday to Friday on 020 7919 2999 or
visit www.nmhct.nhs.uk/pharmacy
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