Sounds like 'a-ten-o-lol'

Atenolol is to treat high blood pressure and prevent chest pain (angina). Find out how to take it safely and possible side effects.

Type of medicine Also called
Belongs to a group of medicines called beta-blockers Mylan Atenolol®

What is atenolol?

Atenolol is used mainly to lower high blood pressure. It can also be used to prevent chest pain (angina) or to treat an irregular heartbeat. It belongs to a group of medicines called beta-blockers. Beta-blockers work by blocking some natural chemicals in the body, to slow the heart rate and lower blood pressure. In New Zealand, atenolol comes as tablets. 


  • The usual dose of atenolol is 50 or 100 milligrams daily. The dose will be different for different people. Some people may need lower doses.
  • Your doctor will usually start you on a low dose, and increase the dose depending on how you respond. This allows your body to get used to the medicine and reduces unwanted side effects.
  • Always take your atenolol exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much atenolol to take, how often to take it, and any special instructions.

How to take atenolol

  • Timing: Take atenolol at the same time each day. You can take atenolol with or without food. Swallow your atenolol tablet with a glass of water.
  • Limit drinking alcohol while you are taking atenolol. It may increase your chance of side effects such as feeling dizzy.  
  • Missed dose: If you forget to take your tablet, take it as soon as you remember that day. But, if it is nearly time for your next tablet, just take the next tablet at the right time. Do not take double the amount of tablets.
  • Keep taking atenolol regularly. Treatment with atenolol is usually long term. Do not stop taking atenolol suddenly; speak to your doctor or pharmacist before stopping.

Precautions before taking atenolol

  • Do you have asthma?
  • Do you have diabetes?
  • Do you have problems with your kidneys?
  • Do you play a professional sport?
  • Are you pregnant or breastfeeding?
  • Have you ever had an allergic reaction to a medicine?
  • Are you are taking or using any other medicines? This includes any medicines you are using which are available to buy from a pharmacy, supermarket or natural health store without a prescription.

If so, it’s important that you tell your doctor or pharmacist before you start taking atenolol. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

What are the side effects of atenolol?

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


If you have diabetes you need to take extra care to measure your blood glucose levels regularly.

  • Beta-blockers can cause an increase in blood glucose levels, especially when you first start taking them. This effect usually settles with time.
  • Beta-blockers may reduce the warning signs of a low blood sugar 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. Do not stop taking your beta-blocker without checking with your doctor first. Read more about hypoglycaemia.


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 are 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.

Other side effects

Side effects What should I do?
  • Tiredness
  • Headache
  • Problems falling asleep or nightmares
  • Nausea (feeling sick) or vomiting
  • These things are quite common when you first start taking atenolol and usually go away with time.
  • Tell your doctor if troublesome.
  • Dizziness
  • Feeling faint when you stand up
  • This is common when you first start taking atenolol.
  • Be careful when getting up from either lying down or sitting to avoid falls.
  • Changes in your heartbeat (either feeling like it is too fast or irregular)
  • Tell your doctor
  • Cold hands and feet
  • Tell your doctor if troublesome
  • Depression or low mood
  • Sexual problems
  • Tell your doctor
  • Problems with breathing such as chest tightness, or wheezing or swelling of the ankles or feet.
  •  Tell your doctor immediately or ring HealthLine 0800 611 116 
For more information on side effects, see the Medsafe consumer information leaflet Mylan Atenolol.

Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product


  • Atenolol may interact with other medications and herbal supplements so check with your doctor or pharmacist before starting atenolol or before starting any new medicines.

  • Also, check with your pharmacist before taking over-the-counter medicines such as:

    • Cold and flu medicines containing phenylephrine (e.g. Sudafed PE)
    • Anti-inflammatories such as diclofenac (e.g. Voltaren Rapid), ibuprofen (e.g. Nurofen), naproxen (e.g. Naprogesic).
    • Herbal or complementary medicines.

Learn more

Medsafe Consumer Information Sheets:   Mylan Atenolol 
New Zealand Formulary Patient Information: Atenolol


  1. Atenolol New Zealand Formulary

Additional resources for healthcare professionals

Mylan atenolol Mesafe, NZ
Hypertension in adults – The silent killer BPAC, NZ, 2013
Medical management of stable angina pectoris BPAC, NZ, 2011
Which antihypertensive BPAC, NZ, 2010

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist Last reviewed: 02 Oct 2018