Venlafaxine

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Efexor/Venlafaxine is a serotonin and noradrenaline re-uptake inhibitor (SNRI) it lacks the sedative and antimuscarinic effects of the tricyclic antidepressants and is a relatively new antidepressant used primarily for the treatment of major depression, generalized anxiety disorder (a form of chronic anxiety), social anxiety disorder, and panic disorder in adults. However, because Venlafaxine has a shorter half-life it is associated with a higher risk of with-drawal problems compared with other antidepressants.

It combines the therapeutic properties of both the tricyclic anti-depressant and selective serotonin reuptake inhibitors (SSRI’s) without the anticholinergic adverse effects (Blocking of acetylcholine receptors in the central and the peripheral nervous system). Adverse effects of anticholinergic medications may contribute to events such as falls, delirium, and cognitive impairment in older patients, so being free from these effects is a big plus especially for the elderly.

Venlafaxine works by affecting the various neuro chemicals in the body which regulate the nervous system. It inhibits specifically norepinephrine and serotonin re-uptake. the drug is said to relieve moodiness, increase the patients physical activity, and restore interest in everyday life. Side effects from this medication are reported to be well tolerated. Due to decreased appetite it is possible weight loss may occur.

Quick Guide

• Antidepressant danger of overdose – HIGH.
• Dependency is said to be – LOW.
• Prescription only drug – YES.
• Available as generic – NO (generic drugs, short: generics) is a drug which is produced and distributed without patent protection.
• Alcohol Avoidance – YES.
• Alcohol may increase the sedative effects of venlafaxine.
• Take Venlafaxine exactly as your doctor has told you.
• Take tablets with food.
• Swallow your tablets whole.
• Modified release Capsules. Do not crush or chew them.
• Try to take your medicine at the same times each day to avoid missing any doses (become habit forming).

Side Effects

You may if prescribed Venlafaxine suffer one or more of these side effects, in the initial stages. However, you may find you do not suffer any at all. It does not automatically follow that being on this medication will cause unwanted adverse effects.

Very Common (affects more than 1 in 10 people):Feeling sick (nausea) Dry mouth, Headache, Sweating more than usual.
Common (affects more than 1 in 10 people):Heart problems including high blood pressure (hypertension), palpitations, flushing. Weight loss, Loss of appetite (anorexia), being sick (vomiting), constipation, Stomach pains, shivering, fever, Sore joints or muscles, stiff or tense muscles.
Rare (affects less than 1 in 1000 people): Difficulty speaking or slurring your words, Feeling aggressive or having aggressive thoughts (more likely at the start of treatment).
Very Rare (affects less than 1 in 10,000 people): Serious chest pain and collapse, Feeling very confused, unsettled and unable to think clearly, Bruising more easily than usual, bleeding for longer than usual after an injury, unusual bleeding from the gums or elsewhere, a rash of purple dark red spots under the skin.

The side effects listed here are the most common, rare and very rare problems reported by patients using Venlafaxine. It may not include all of the side effects reported by the drug’s manufacturer. If common side effects persist you need to inform your doctor. Notify your doctor if you suffer any of the rare or some other side effects not listed here.

Prolonged Use

Venlafaxine is said to be well tolerated. There are reports of weight loss and some sexual difficulties. There is also mention of high doses of venlafaxine causing an increase in blood pressure, with the adjustment of the dosage this can be controlled. However, periodical blood tests may need to be carried out.

Driving, Hazardous Work & Alcohol

Avoid driving/hazardous work until you know how venlafaxine affects you. Venlafaxine can cause blurred vision,drowsiness and dizziness. Alcohol may increase the sedative effects of venlafaxine. Manufacture advises avoid alcohol.

Pregnancy and Breast-Feeding

Safety in pregnancy is not known. Both pregnancy and breast-feeding are not recomended. However, a doctor may prescribe this medicine if they consider the potential benefit outweighs the risk. Discuss both these important issues with your doctor.

Patient information shows venlafaxine as Category C… Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, only if the potential benefits of the drug in pregnant women out-weigh the potential risks to the fetus.

Tell Your Doctor Or Pharmacist

You should tell your doctor if you have a current health problem. For example: heart disease, kidney problems, if you are pregnant or you intend to become pregnant, or if you think you may be at risk from drug treatment for any other reason. Some types of medication can cause serious adverse effects when taken side by side so it is important to tell your doctor of any other medication you are already taking. This should also include any over-the-counter medication. For example: Painkillers, cold remedies, herbal and complimentary / alternative preparations.

Over 60’s & Children

A reduced dose may be necessary for the over 60′s as there is a likely-hood of increased side-effects. The balance of risks and benefits for the treatment of depressive illness in individuals under 18 years is not recommended.

Overdose

If you have taken a lot of tablets at the same time or you believe a child may have swallowed some seek immediate medical advice in all cases. In cases of overdose Venlafaxine may cause A very fast heart beat, Being drowsy, sleepy, confused or less aware of your surroundings than usual, Blurred vision, Fits (seizures) Being sick (vomiting). Notify your Doctor immediately.

Failing this go to your nearest accident and emergency department of your local hospital. Take the container with you even if it is empty. This will help the hospital staff identify what has been taken and work towards given the right kind of help without delay.

Worsening of your depression or anxiety

If you have had thoughts in the past of harming or killing yourself these could be increased when first starting an antidepressant for depression and/or anxiety disorders, since these medicines all take time to work, usually 2 weeks for some individuals, but it is possible to take longer in some individuals (4 weeks). You may be more likely to think like this If you have previously had thoughts about killing or harming yourself in the past.

If you have thoughts of harming or killing yourself at any time, contact your doctor or go to a hospital straight away. Information from clinical trails have shown there is an increased risk of suicidal behaviour in young adults under the age of 25 years with psychiatric disorders.

Other Medication Reactions

All drugs that have a sedative effect on the nervous system will more likely than not increase the sedative properties of Venlafaxine. Venlafaxine should not be taken along-side Monoamine Oxidase Inhibitors (MAOIs). A two week period free from MAOI’s should elapse before venlafaxine is administered. This is because dangerously high blood pressure may result from the combination. If high doses of venlafaxine are prescribed then blood pressure monitoring should be carried out periodically.

Other medication that may interact with Venlafaxine are:

• Medicines for migraine attacks and cluster headaches such as: sumatriptan (triptans).
• Medicines for depression such as Serotonin–norepinephrine reuptake inhibitor (SNRI), selective serotonin reuptake inhibitors (SSRIs) e.g. Fluoxetine, Paroxetine. Tricyclics antidepressants (TCAs) e.g. Amitriptyline, or medicines containing lithium.
• Antibiotics used to treat infections such as: linezolid.
• Medicines used to treat depression such as: moclobemide (reversible MAOIs).
• Medicines that help with weight loss such as: sibutramine.
• Venlafaxine may reduce the effectiveness of antihypertensive drugs (e.g. Indoramin).
• Herbal products such as St John’s Wort (also called Hypericum perforatum) or tryptophan supplements.

Missed A Dose

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and continue the regular dosing schedule. Do not take a double dose to make up for a missed one.

Reducing or Stopping Medication

Do not stop your medication without first consulting with your doctor. Stopping abruptly can cause distressing withdrawal symptoms. If your doctor thinks that you no longer need Venlafaxine they will suggest reducing them over a period of time before stopping treatment altogether. This will help to reduce the chance of withdrawal symptoms.

Effect Of Medication

Effects can be felt within days, but it may take 2 to 4 weeks before the full antidepressant effects will be felt. The duration effects can be felt for 8 to 12 hours. 24 hours for SR Capsules, following prolonged treatment. The antidepressant effects could be felt for up to 6 weeks.

Safety and Storage

• Never take more than the original dosage prescribed by your doctor.
• If your due to have treatment like an operation or dental work tell the person carrying out the treatment which medicines you are taking.
• When you buy any medicines over-the-counter check with the pharmacist that they are safe to take with your other medicines.
• Never take Venlafaxine if it has past the expiry date shown on the box or container.
• Do not store medication above a temperature of 25°C or above a working area where high condensation may exist.
• Keep Venlafaxine in its original container, in a cool dry place, away from the reach and eye sight of children.
• Always read the printed information leaflet that comes with your medicine if possible, before beginning treatment.
• Do not dicard the Patient Information Leaflet (PIL) you may need to refer to it a later date.
• Do not discard old or unwanted drugs into your trash, sink or toilet.
• Return all unused or old medicines/drugs to your pharmacist. who will dispose of them safely. without causing unwanted effects on our enviroment.

If Venlafaxine has been prescribed for you never allow anyone else to use it, even if you know or others feel their symptom are similar to your own.

Do not leave your doctors surgery until you have a clear understanding of what the medicine your doctor has prescribed for you does, and why you have been prescribed it. It is common for people who do not understand the reason behind their treatment to take their medication correctly.

Reference:

The link below assumes you already have Adobe Acrobat Reader installed on your computer. You will need it to read the Patient Information Leaflet. If you have not you can down load Adobe Acrobat Reader it free from Adobe.com.

• Winthrop Pharmaceuticals UK Ltd Patient Information Leaflet (PIL) last updated on electronic Medicines Compendium eMC: 24/08/2010. Venlafaxine 37.5mg, 50mg & 75mg Tablets.
• Pfizer Limited Patient Information Leaflet (PIL) last updated on electronic Medicines Compendium eMC: 08/11/2011. Efexor XL Tablets.
• British National Formulary – 61st Edition (March 2011) British Medical Association and Royal Pharmaceutical Society of Great Britain, London.