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What does it do?

Phenelzine is used to treat and prevent depression, and sometimes other conditions.

How should you take it?

Take phenelzine regularly as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

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

  • cold and flu medicines containing dextromethorphan (e.g. Robitussin Dry Cough Forte®), oxymetazoline (e.g. Drixine®), phenylephrine (e.g. Sudafed PE®) or xylometazoline (e.g. Otrivin®)
  • some migraine medicines, such as sumatriptan (e.g. Sumagran Active®) or zolmitriptan (e.g. Zomig®)

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).

What side effects might you notice?

Side EffectsRecommended action

Suicidal thoughts

Severe headache, changes in vision, nausea, vomiting, change in heartbeat

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

Symptoms of liver problems including: yellow skin or eyes, itching, dark urine, pale bowel motions, abdominal pain

Tell your doctor immediately

Strange or uncontrolled movements, restlessness

Tell your doctor

Dizziness, drowsiness, trouble sleeping

Muscle weakness

Changes in sexual function, trouble peeing

Constipation, dry mouth

Weight gain, swollen feet or legs

Tell your doctor if troublesome

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

Other information:

  • While you are taking phenelzine and for two weeks after stopping, you MUST not eat foods and alcohol that contain tyramine. These may cause a very serious reaction and include: cheese, meat or yeast extracts (e.g. Marmite®, Vegemite®, Oxo®), pickled fish, broad bean pods, sauerkraut, salami and protein drinks. This list is a guide only – talk to your health professional.
  • Tell your doctor if you have kidney, liver, thyroid, heart or blood pressure problems.
  • Tell your doctor if you have a history of frequent headaches, stroke, diabetes, seizures, bipolar disorder, or glaucoma.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Phenelzine 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?)
  • If you are having surgery, it is important to tell your doctor that you are taking phenelzine.
  • It may take a few weeks for phenelzine to start working.
  • Feelings of anxiety in the first few weeks of therapy are common, but should get better. Discuss with your doctor.
  • If your depression continues to get worse, see your doctor.
  • Do not stop taking phenelzine without talking to your doctor first.

This leaflet contains important, but not all, information about this medicine.

Prepared by the PILs Committee at Christchurch Hospital, Canterbury District Health Board, New Zealand. January 2020

For more general information about this sheet annd its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at the Canterbury District Health Board. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed