How it works
What does propranolol do?
Propranolol is a beta-blocker medicine, which helps to reduce the symptoms of anxiety, including sweating and shaking. It doesn’t treat the feeling of anxiety, only the physical symptoms that come with it.
When you are anxious your brain makes more of the chemicals noradrenaline and adrenaline, both of which can make your heart beat faster and can make you shake and sweat. Propranolol blocks the effects of these chemicals.
How long does it take propranolol to start working?
You will get the effect of propranolol quickly - usually within a few hours.
How long will I need to take propranolol?
You should talk to your doctor about how long you will need to take propranolol for before you start treatment.
Some people only need to take propranolol for a few days.
Other people will take it regularly for months or even years.
If you are taking it for a long time, make sure that you see your doctor for a review every six months.
Your doctor needs to know if...
You need to talk to your doctor or pharmacist before you take propranolol if any of the following apply to you:
- you have asthma or any other breathing difficulties
- you have any heart problems
- you have low blood pressure
- you have diabetes mellitus (symptoms of low blood sugar levels may be hidden by this medicine)
- you have a tight, painful feeling in the chest even when you rest (Prinzmetal’s angina)
- you have untreated high blood pressure due to a tumour near the kidney (phaeochromocytoma)
- you have muscle weakness (myasthenia gravis)
- you have kidney or liver disease
- you have an overactive thyroid (symptoms of hyperthyroidism include increased appetite, weight loss, sweating)
- you have, or have ever had, psoriasis
- you have serious blood circulation problems (which may cause your fingers and toes to tingle or turn pale or blue)
- you have Raynaud’s disease (cold sensations in fingers and toes) or intermittent claudication (narrowing of arteries in the legs causing pain on walking)
- you smoke (propranolol may carry a higher risk of making your breathing more difficult)
- you know that you are going to have surgery soon, as the effects of propranolol on your heart mean a risk of effects on your heartbeat while you are under a general anaesthetic
- you are having any blood or urine tests (propranolol can change the results of some lab tests)
- you have food allergies and carry an adrenaline injection (epi-pen), as propranolol could reduce the effectiveness of this
What does propranolol contain?
Propranolol tablets may not be suitable for you if you have problems eating some sugars or dairy (milk-based) foods, as they contain lactose.
Some propranolol tablets may contain colours that can cause an allergic reaction.
The capsules contain gelatin and sucrose.
Talk to your pharmacist or doctor if you are allergic to any food additives.
Propranolol long-acting capsules contain gelatin, and this may be a problem if you don't eat meat.
The liquid may contain methyl and propyl parahydroxybenzoates and the food additive colour sunset yellow (E110) which may cause an allergic reaction in some people.
The liquid may also contain maltitol (a type of sugar related to fructose). If your doctor has told you that you cannot eat some sugars, check with your doctor before taking it.
You should only take propranolol as agreed with your doctor
Make sure that you know your dose. If it is not written on the label, check with your pharmacist or doctor.
Your doctor might change your dose a few times at the beginning to find the right level for you.
You may have to take it up to three times a day.
It doesn’t matter what time you take it each day - choose a time that you can always remember. This could be a mealtime, or when you brush your teeth. If you take propranolol more than once a day, spread the doses as evenly as possible throughout the day.
If you can, take it before a meal or some food.
Swallow the tablet with a drink of water - if you chew it, it tastes bitter.
If you find it difficult to take it more than once a day, ask your doctor about the long-acting capsules because they only need to be taken once a day.
Swallow the capsules whole with a drink of water - they are specially made to release the medicine over a few hours into your body and should not be crushed or chewed.
What if I miss a dose?
If you remember later, take it as soon as possible.
If you forget to take it until just before your next dose, just start again with the next dose.
Do not take a double dose.
What will happen if I forget to take my propranolol?
If you forget to take your tablets for a few days, you may start getting withdrawal symptoms, some of which can be dangerous to your heart.
Please talk to your doctor or pharmacist and look out for any withdrawal symptoms.
Stopping the use of propranolol
If you want to stop taking propranolol, you should ask your doctor for help. Stopping this medicine quickly, or reducing the dose too much at once, may cause withdrawal symptoms that are dangerous to your heart.
These symptoms include:
- irregular heartbeat
- chest pain, which may be angina or a heart attack
You will need to go to hospital if you get these symptoms, as your heart could be in serious trouble.
If you go to your doctor for help to stop, they will reduce your dose slowly and safely over about two weeks.
The information on this page was reviewed by the College of Mental Health Pharmacy in March 2020.