NZ Formulary

Venlafaxine

ven-lah-fax-een

What does it do?

Venlafaxine is used to treat depression, and sometimes other conditions.

Before you start

  • Tell your doctor if you have heart or bleeding problems, angle-closure glaucoma, bipolar disorder, or if you have ever had a seizure.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Your doctor may do a heart test (ECG) before you start and while you are taking venlafaxine.

How should you take it?

Take venlafaxine regularly as directed. Swallow the capsules whole with a glass of water. You can take it with or without food.

What if you forget a dose?

If it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with venlafaxine including:

  • anti-inflammatories, such as diclofenac (e.g. Voltaren®), ibuprofen (e.g. Nurofen®), or aspirin (e.g. Disprin®, in doses used for pain relief). These can also be found in some cold and flu medicines (e.g. Nurofen Cold and Flu®).
  • low-dose aspirin (e.g. Cartia®)
  • some migraine medicines, such as sumatriptan (e.g. Sumagran Active®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs (e.g. ecstasy).

Important information continues on next page.

What side effects might you notice?

Side EffectsRecommended action

Suicidal thoughts

Muscle twitching or shaking you can’t control, confusion, heavy sweating, fever

Symptoms of a fast or irregular heartbeat including: fluttering, pounding or pain in your chest, dizziness or fainting

Seizures

Tell your doctor immediately

Anxiety, restlessness

Easy or unusual bruising or bleeding

Tell your doctor

Drowsiness, yawning, tiredness or weakness, trouble sleeping

Dizziness, blurred vision

Flushing, sweating

Nausea, vomiting, constipation

Dry mouth, loss of appetite, weight loss

Less interest in, or trouble having sex

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Venlafaxine can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • It may take a few weeks for venlafaxine to start working.
  • Do not stop taking venlafaxine without talking to your doctor first.