Sounds like 'met-oh-proe-lol'

Key points about metoprolol

  • Metoprolol has many uses including after a heart attack (to prevent heart damage) and for heart failure, high blood pressure and irregular heart beat.
  • Metoprolol is also called Betaloc CR, Lopresor, Myloc or Slow Lopresor.
  • Find out how to take it safely and possible side effects.
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November 2023: The funded brand of metoprolol slow release tablets is changing

From November 2023, a new brand of metoprolol slow release tablets, Myloc CR will be funded. Myloc CR has the same active ingredient and works the same way as Betaloc CR. Find out more about Metoprolol: your brand is changing(external link).

Metoprolol is used to treat many conditions including after a heart attack (to prevent heart damage), and for heart failure, high blood pressure (hypertension), and irregular heart beat. It belongs to a group of medicines called beta-blockers. Metoprolol works by slowing down your heart rate and making it easier for your heart to pump blood around your body. Metoprolol is also used to prevent migraine headaches.   

In Aotearoa New Zealand metoprolol comes as tablets – immediate release tablets and controlled release tablets.

  • Check with your pharmacist which form you are taking.
  • The dose of metoprolol will be different for different people.
  • Always take metoprolol exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much metoprolol to take, how often to take it, and any special instructions. 
  • If you're not sure how much to take, ask your doctor, nurse or pharmacist.
  • Check with your pharmacist if your tablets are different to what you expect.

  • Immediate release tablets:
    • Take these as you have been prescribed (usually 2 or 3 times a day).
    • Take your doses at the same times each day.
  • Controlled release tablets (usually has CR after the name):
    • Take these tablets once a day.
    • Swallow the tablets whole, with a glass of water – don't crush or chew them.
  • You can take metoprolol with or without food.
  • If you forget your dose, take it as soon as you remember that day. But if it's nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.
  • Don't stop taking metoprolol suddenly, talk to your doctor or nurse before stopping.

Here are some things to know when you're taking metoprolol. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Avoid alcohol while you're taking metoprolol, especially when you first start treatment. Alcohol can increase your risk of side effects such as dizziness.
  • Metoprolol can interact with other medicines. Tell your doctor or pharmacist about all medicines you are taking including over the counter medicines or herbal and complementary medicines.

If you have diabetes

  • If you have diabetes, metoprolol may cause changes in your blood glucose level. This effect usually settles with time.
  • Beta-blockers may reduce the warning signs of a low blood glucose level (hypoglycaemia – often called a hypo). For example, you may not have the feeling of fast, irregular or strong heartbeats (palpitations) or tremor, which can occur when your blood glucose is going too low.
  • If you are worried about this, talk to your doctor. Don't stop taking your beta-blocker without checking with your doctor first. Read more about hypoglycaemia.

If you have asthma

  • If you have asthma, taking a beta blocker may trigger your asthma symptoms or make them worse. Not everybody with asthma is sensitive to these medicines.
  • If you're worried about this, talk to your doctor. They may be able to prescribe a different medicine or increase the dose of your asthma preventer medication.
  • Do not suddenly stop taking your beta-blocker without talking to your doctor first. This can be dangerous and make you feel unwell. Read more about medicines that may trigger asthma symptoms.

Like all medicines, metoprolol can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Tiredness
  • Headache
  • Nausea (feeling sick) or vomiting (being sick)
  • Problems sleeping
  • These are quite common when you first start taking metoprolol, and usually go away with time.
  • Tell your doctor if they bother you.
  • Dizziness
  • Feeling faint when you stand up
  • This is common when you first start taking metoprolol.
  • Don't drink alcohol.
  • Be careful when getting up from either lying down or sitting to avoid falls.
  • Cold hands and feet
  • Tell your doctor if they bother you.
  • Depression and low mood
  • Sexual problems
  • Tell your doctor.
  • Problems with breathing, eg, chest tightness, or wheezing or swelling of the ankles or feet.
  • Tell your doctor immediately or ring Healthline 0800 611 116.
Did you know that you can report a medicine side effect to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.(external link)

The following links have more information on metoprolol.

Metoprolol(external link) New Zealand Formulary Patient Information English(external link), te reo Māori(external link)

Medsafe Consumer Information Sheets

Metoprolol leaflet Institute for Innovation and Improvement and Waitematā DHB, NZ


Metoprolol Institute for Innovation and Improvement and Waitematā DHB, NZ, 2020 Black/white [PDF, 4.1 MB], Colour(external link)
Metoprolol in te Reo Māori(external link)(external link) My Medicines, NZ
5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019 English(external link), te reo Māori(external link)


  1. Metoprolol succinate(external link) New Zealand Formulary
  2. Metoprolol tartrate(external link) New Zealand Formulary


metoprolol wdhb brochure


Institute for Innovation and Improvement and Waitematā DHB, NZ, 2020
Colour, Black/white [PDF, 4.1 MB]

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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