Venlafaxine is used to treat depression. It is also used to treat anxiety and panic attacks.
Take Venlafaxine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
Take it together with food or immediately after a meal. Try to take it at the same time each day.
This medicine is available as a tablet or capsule.
If you are taking the prolonged-release type of capsule (usually labeled as XL, XR), swallow it whole. Do not divide, chew or crush the capsule.
Venlafaxine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed otherwise, as stopping it suddenly could worsen your condition.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take you medicine, let your doctor and pharmacist know.
Do not give this medicine to children unless instructed to do so by the doctor.
Do not take Venlafaxine if you are taking or have taken medicine to treat depression known as monoamine oxidase (MAO) inhibitors in the last 14 days. Do not take MAO inhibitors within 7 days of stopping this medicine. Please see the section “Can I take this with other medicines?” below for more information.
Inform your doctor if you have the following conditions:
- history of suicide or suicidal thoughts
- glaucoma (increased pressure in the eyes)
- heart disease e.g. recent heart attack, heart failure
- history of seizures or fits
- bleeding tendencies
- bipolar disorder [mood changes between feeling very high (mania) and very low (depression)]
- history of aggressive behavior
- dehydration or low blood volume
- kidney disease
- liver disease
Let your doctor know if you are pregnant or breastfeeding.
Be sure to check with your doctor or pharmacist before giving Venlafaxine to an elderly. Elderly may be more sensitive to the side effects.
A certain enzyme called CYP2D6 is involved in the metabolism of Venlafaxine. Certain genetic traits or lacking CYP2D6 enzyme activity may affect the effectiveness of this medicine. Individuals who are heterozygous extensive metabolisers or poor metabolisers of CYP2D6 may respond poorer to Venlafaxine and may have higher risks of experiencing side effects. Although not routinely done, your doctor may advise you to take genetic testing to check if this medicine is best suited for you. If you know you have either of these gene types, inform your doctor.
Medicines for depression such as Venlafaxine may increase the risk of suicidal thoughts and behaviour. As depression and some psychiatric disorders are themselves associated with an increased risk of suicide, it is important for you or your family members to monitor your condition especially at the start of treatment and if your dosage is still being adjusted. If you experience new or sudden changes in mood, behaviour, thoughts or feelings or a worsening of your depression with suicidal thoughts or attempts, harm to self or harm to others, contact your doctor immediately.
Why is it important to keep my appointments with the doctor?
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
- Routine cholesterol test may be done if you are taking this medicine for a long period of time.
- Your blood pressure may rise to unsafe levels without you noticing it. Monitor your blood pressure before and during treatment.
Your doctor will advise you about how often you will need to have these tests.
What lifestyle changes should I make to cope with depression?
Regular exercise and eating a healthy diet will help increase energy and hormones in the body such as serotonin, endorphins and other feel-good chemicals that minimise mood swings. Get enough sleep, as lack of sleep may cause irritability, moodiness, sadness, and tiredness.
Venlafaxine may cause drowsiness, dizziness or blurred vision. If affected, do not drive or take part in any activity in which you need to be alert or need to see clearly.
Other side effects include any of the following: headache, nausea, vomiting, constipation, diarrhoea, rash, itching, tiredness, weakness, chills, unusual sweating, dry mouth, loss of appetite, weight gain or loss, hot flushes, muscle stiffness, tingling or pricking sensation, changes in taste, ringing of the ears, urination problems, nervousness, anxiety, difficulty sleeping, abnormal dreams, menstrual irregularities in women.
This medicine may also cause decreased sex drive and sexual dysfunction in men. Discuss with your doctor if you are concerned regarding these side effects.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- unusual changes in mood or behaviour (being aggressive, feeling more depressed, suicidal thoughts)
- hyperactive, feeling of unusual overexcitement
- fits or seizures
- jerky movements or other uncontrollable movements
- prolonged dilated pupil
- restlessness, hallucinations, loss of coordination, rapid or fast heartbeat, increased body temperature
- unusual bleeding, bruising, tiny circular patches on the skin
- difficulty breathing, chest pain, fainting, lightheadedness
- dry cough, lasting tiredness, bulb-like development of fingertips and nails
- fever, chest pain, shortness of breath
- loss of energy, irritability, muscle weakness, spasms or cramps
This medicine may cause your blood pressure to fall suddenly when you get up from a sitting or lying down position and you may feel giddy. To minimise this problem, stand up slowly.
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Do not take Venlafaxine if:
- you are currently taking or have taken a medicine to treat depression known as a monoamine oxidase inhibitor (MAOI) such as isocarboxazid, phenelzine and tranylcypromine in the last 14 days
- you are being treated with a certain antibiotic e.g. linezolid
- you are given an injectable solution for blood disorders e.g. methylene blue
Do not take MAOIs within 7 days of stopping Venlafaxine.
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for weight loss e.g. phentermine, sibutramine
- blood-thinning medicines e.g. warfarin, aspirin
- medicines for diabetes e.g. insulin
- medicines for high blood pressure or heart disease e.g. metoprolol, amiodarone
- medicines for migraine e.g. sumatriptan, zolmitriptan
- medicines to treat fungal infections e.g. ketoconazole, itraconazole
- medicines for HIV infection e.g. atazanavir, indinavir
- NSAIDs (medicines for pain and inflammation) e.g. ibuprofen
- antibiotics e.g. clarithromycin, moxifloxacin
- other medicines for depression e.g. fluoxetine, duloxetine
- medicines for mood disorders e.g. lithium, haloperidol, risperidone, thioridazine
- strong painkillers e.g. tramadol, fentanyl
- herbal medicine e.g. St John's wort
This list does not include all medicines that may interact with Venlafaxine.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children. Protect from light and moisture.
Medicines must not be used past the expiry date.