Propranolol belongs to the class of medications called beta-blockers. It is used to treat high blood pressure. It is also used to prevent angina (chest pain), to manage certain heart conditions, and to treat certain types of abnormal heart rhythms. Propranolol works by relaxing blood vessels and reducing the demands on the heart.

Propranolol is also used for the prevention of migraines.  It is also used, in combination with other medications, to manage the symptoms caused by pheochromocytoma (a tumour of the adrenal glands).

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose of propranolol varies widely according to the condition being treated and circumstances of the person taking the medication. Propranolol may be taken with or without food. Do not stop taking this medication suddenly unless you have talked with your doctor first.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture and keep it out of the reach of children.

Do not take this medication if you:

• are allergic to propranolol or any ingredients of the medication
• are in cardiogenic shock
• are prone to low blood glucose
• have a severely slow heart rate
• have allergic rhinitis during the pollen season
• have asthma or severe chronic obstructive respiratory diseases (e.g., emphysema, chronic bronchitis)
• have congestive heart failure
• have right ventricular failure secondary to pulmonary hypertension (excessive blood pressure in the lungs)
• have serious heart block (second- and third-degree AV block) or sick sinus syndrome
• have severe circulatory disorders
• have a condition where the blood is acidic
• have severely decreased blood pressure
• have untreated pheochromocytoma (a tumour of the adrenal glands)
• have Prinzmetal angina (a condition that causes angina or chest pain at rest)
• have uncontrolled heart failure

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• diarrhea
• dizziness
• dry eyes
• fatigue
• headache
• loss of appetite
• nausea
• nightmares
• trouble sleeping
• unusual tiredness or weakness
• vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• breathing difficulty or wheezing
• chest pain
• cold hands and feet
• dizziness when rising from a sitting or lying position (orthostatic hypotension)
• hallucinations (hearing or seeing things that aren't there)
• memory problems
• mood changes (e.g., confusion, anxiety, trouble concentrating)
• ringing in the ears
• sleepwalking
• slow heartbeat (especially less than 50 beats per minute)
• signs of heart failure (e.g., shortness of breath, fatigue, swelling in legs, ankles, feet)
• symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heart beat, weakness
• symptoms of low blood pressure (e.g., dizziness, fatigue)
• symptoms of Raynaud's phenomenon (numbness and spasm in fingers followed by warmth and pain)
• unusual bleeding or bruising
• vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a serious skin rash (such as redness, blistering, peeling, or loosening of skin)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Breathing problems: In general, people who have asthma and certain other breathing problems or chronic lung disease should use propranolol cautiously, as it can cause breathing difficulty. Low doses of propranolol may be taken with caution by those with asthma who do not respond to or cannot tolerate other treatments. If you have breathing problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Congestive heart failure: People with congestive heart failure should not take propranolol.

Diabetes: The signs of low blood sugar may not be as noticeable when taking propranolol. If you have diabetes and take insulin or other medications that affect blood glucose levels, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. It may be necessary to monitor your blood glucose levels more often when you are taking this medication.

Low blood pressure: Occasionally, blood pressure drops too low after taking propranolol, causing dizziness or lightheadedness. Move slowly when moving from a lying down or sitting position to a standing position to prevent dizziness, especially when this medication is first being started.

Hyperthyroidism (high level of thyroid hormones): Propranolol can reduce the symptoms that occur when you have hyperthyroidism (high levels of thyroid hormones). It does not affect the thyroid gland, it only hides the symptoms of an over-active thyroid gland. Stopping the medication suddenly could worsen this condition.

Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have kidney problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Pheochromocytoma: This medication can worsen the symptoms of pheochromocytoma (a tumour of the adrenal gland) if it is taken alone. If you have a pheochromocytoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Severe allergies: People with allergies severe enough to cause anaphylaxis (a severe allergic reaction where swelling of the face, lips, and throat make it difficult to breathe) should talk to their doctor about what to do if they have an allergic reaction. Propranolol may make it more difficult to treat their allergic reaction with epinephrine.

Stopping medication: Propranolol should not be stopped suddenly by people who are taking it to treat angina. There have been reports of severe worsening of angina and of heart attack or abnormal heart rhythms occurring for people with angina pectoris who have stopped the medication abruptly. If you feel that you need to stop this medication for any reason, talk to your doctor for the best way to taper the medication.

Surgery: If you are scheduled for surgery, inform all doctors involved in your care that you take propranolol.

Pregnancy: Not enough information exists on the safe use of propranolol by pregnant women; however, studies have shown that propranolol does cross the placenta. Propranolol should be used during pregnancy only if the potential benefits justify the potential risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking propranolol, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: There is limited experience in the use of propranolol by children. Caution is advised with its use by this age group.

There may be an interaction between propranolol and any of the following:

• abiraterone
• acarbose
• alcohol
• aldesleukin
• aliskiren
• alpha agonists (e.g., clonidine, methyldopa)
• alpha blockers (e.g., alfuzosin, doxazosin, tamsulosin)
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• angiotensin-converting enzyme inhibitors (ACEIs; captopril, ramipril)
• angiotensin receptor blockers (ARBs; e.g., candesartan, irbesartan, losartan)
• antiarrhythmic medications (e.g., amiodarone, disopyramide, flecainide, mexiletine, lidocaine, procainamide, propafenone, quinidine, sotalol)
• antipsychotic medications (e.g., chlorpromazine, clozapine, haloperidol, risperidone)
• apomorphine
• barbiturates (e.g., butalbital, phenobarbital)
• beta-2 agonists (e.g., salbutamol, formoterol, terbutaline, salmeterol)
• brimonidine
• bromocriptine
• bupropion
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• cannabis
• celecoxib
• ceritinib
• Cholestyramine
• cinacalcet
• ciprofloxacin
• cimetidine
• clomipramine
• colestipol
• conivaptan
• darifenacin
• darunavir
• deferasirox
• dexmethylphenidate
• diabetes medications (e.g., acarbose, canagliflozin, glyburide, insulin, linagliptin, lixisenatide, metformin, repaglinide)
• diazoxide
• digoxin
• dipyridamole
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
• donepezil
• duloxetine
• epinephrine
• ergot alkaloids (e.g., dihydroergotamine, methysergide)
• exenatide
• fentanyl
• galantamine
• grass pollen allergen extract
• guanfacine
• hydralazine
• imipramine
• ivabradine
• lacosamide
• levodopa
• mefloquine
• methylphenidate
• minoxidil
• mirabegron
• morphine
• nabilone
• nitrates (e.g., nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., diclofenac, ibuprofen, ketorolac, naproxen)
• obinutuzumab
• other beta-adrenergic blockers (e.g., atenolol, propranolol, sotalol)
• pentoxifylline
• phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
• pilocarpine
• primidone
• rasagiline
• rifampin
• riociguat
• rivastigmine
• ropinirole
• rotigotine
• sacubitril
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, fluvoxamine, paroxetine, sertraline)
• selegiline
• somatostatin-like medications (e.g., lanreotide, octreotide, pasireotide)
• sphingosine 1-phosphate receptor (S1P) receptor inhibitors (e.g., fingolimod, ponesimod, siponimod)
• tacrolimus
• terbinafine
• teriflunomide
• theophyllines (e.g., theophylline, aminophylline, oxtriphylline)
• tipranavir
• tizanidine
• tranylcypromine
• tretinoin
• white birch allergen extract

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.