Propranolol is a drug belonging to the β-blocker class. It is marketed as propranolol hydrochloride with the name of Inderal®.
Propranolol - Chemical Structure
Indications
For what it uses
The use of propranolol is indicated in the following cases:
- Angina pectoris treatment;
- Control of arterial hypertension;
- Post-infarct prophylaxis;
- Control of cardiac arrhythmias;
- Treatment of essential tremor;
- Prophylaxis of migraine;
- Control of anxiety and tachycardia on an anxious basis;
- Adjuvant in thyrotoxicosis therapy;
- Treatment of hypertrophic obstructive cardiomyopathy;
- Treatment of pheochromocytoma (in association with β-blockers).
Warnings
Before starting treatment with propranolol, it is good to inform your doctor if you have liver, kidney, respiratory, thyroid or cardiovascular disease or if you have diabetes. Also, you must tell your doctor if you are already taking verapamil or diltiazem (calcium channel blockers used to treat arrhythmias).
Propranolol may cause a reduction in heart rate. Usually, this effect is normal, but if it becomes a cause for concern, it is good to inform your doctor.
In patients with peripheral vascular disorders, propranolol can cause a worsening of the disorders associated with them.
Propranolol may cause hypoglycaemia, even in patients without pre-existing diabetes.
Propranolol could cause side effects that could affect the ability to drive or use machines, therefore, caution should be used.
For those who perform sports, the use of the drug without therapeutic necessity is doping and, in any case - even when used at therapeutic doses - it can determine positivity to doping tests.
Interactions
A lot of caution should be used in the use of anesthetics in patients taking propranolol. Therefore, if you need to undergo surgery, you need to tell your doctor if you are on medication.
Before starting propranolol therapy, you need to tell your doctor if you are taking any of the following medications:
- Disopyramide, quinidine or propafenone (for the treatment of arrhythmias);
- Chlorpromazine or thioridazine (antipsychotic drugs);
- Indomethacin or ibuprofen (analgesic drugs);
- Drugs based on ergot derivatives used for the treatment of migraine;
- Rizatriptan, a drug used in the treatment of migraine;
- Clonidine, nifedipine, nisoldipine, nicardipine, isradipine, lacidipine or hydralazine (drugs used to treat hypertension);
- Digoxin, a drug used to increase the strength of cardiac contractility;
- Cimetidine, a drug used in the treatment of gastric ulcer;
- Theophylline, used in the treatment of asthma;
- Rifampicin, an antibiotic used to treat tuberculosis;
- Anticoagulant drugs;
- Nasal decongestants or other medicines used to treat colds.
Alcohol intake during propranolol therapy should be avoided.
Propranolol may change the response to insulin or other drugs used to treat diabetes.
Side effects
Propranolol can cause various types of adverse effects, although not all patients experience them. This depends on the sensitivity of each individual to the drug.
Below are the main side effects that may occur during therapy with propranolol.
Gastrointestinal disorders
Treatment with propranolol may cause nausea, vomiting and diarrhea.
Lung and respiratory tract disorders
In patients with asthma - during treatment with propranolol - worsening of breathing difficulties may occur.
Cardiovascular disorders
Propranolol therapy may cause:
- Slow heart rate;
- Raynaud's phenomenon;
- Wheezing and / or swelling of the ankles in patients suffering from heart failure;
- Heart block;
- Changes in blood circulation.
Nervous system disorders
Dizziness, tiredness, fatigue and confusion may occur during treatment with propranolol.
Psychiatric disorders
Propranolol therapy may cause:
- Sleep disorders;
- Nightmares;
- Mood changes;
- Psychosis;
- Hallucinations.
Other side effects
Other side effects that may occur during therapy with propranolol are:
- Hair loss;
- fainting;
- Vision disorders;
- Skin rash and worsening of psoriasis in patients who are affected;
- Plateletopenia (reduction in the number of platelets in the bloodstream);
- Purple;
- Myasthenia gravis;
- Hypoglycaemia in diabetic and non-diabetic patients, in fasting patients or in patients with chronic hepatic insufficiency. Sometimes, seizures associated with hypoglycemia can occur.
Overdose
If you suspect you have taken an overdose of propranolol you should contact a doctor immediately and go to the nearest hospital.
Action mechanism
Propranolol acts by antagonizing the β1 and β2 receptors for adrenaline and noradrenaline that are found in the heart.
Mode of Use - Posology
Propranolol is available for oral administration as tablets.
The dosage of the drug varies according to the pathology to be treated.
Hypertension
The initial dose administered is 40 mg of propranolol twice a day.
Generally, the usual doses range from 160 mg to 320 mg of drug per day.
Angina pectoris, anxiety, migraine, essential tremors
In these cases, the initial dose of propranolol is 40 mg, to be taken two or three times a day. The dose can be increased depending on the patient's response to the therapy.
In the treatment of anxiety, migraine and essential tremor, an adequate response is usually obtained with a dose of 80-160 mg of drug per day.
In the treatment of angina pectoris, on the other hand, the maximum dose of 240 mg of drug per day should not be exceeded.
Cardiac arrhythmias, tachycardia on an anxious basis, hypertrophic obstructive cardiomyopathy and thyrotoxicosis
In these cases, the dose of propranolol usually used is 10-40 mg three or four times a day.
Post-infarct prophylaxis
Treatment with propranolol should be started between the fifth and twenty-first day after myocardial infarction. The dose of medication usually administered is 40 mg four times a day.
Pheochromocytoma
In the treatment of pheochromocytoma, propranolol can be used only in combination with β-blockers. The dose of propranolol varies - depending on the case - from 30 mg to 60 mg a day.
children
In some cases, propranolol can also be used to treat arrhythmias in children. The dose of drug to be administered must be established by the doctor, depending on the age and body weight of the child.
Pregnancy and breastfeeding
If you are pregnant, you must inform your doctor before starting treatment with the drug.
The use of propranolol is not indicated during pregnancy and lactation.
Contraindications
The use of propranolol is contraindicated in the following cases:
- Known hypersensitivity to propranolol;
- In patients with a history of bronchial asthma, bronchospasm or chronic obstructive pulmonary disease;
- In patients suffering from bradycardia, hypotension or with severe peripheral arterial circulation disorders;
- In patients with cardiogenic shock;
- In patients with second or third degree atrioventricular block;
- In patients with sinus node syndrome;
- In patients with heart failure;
- In patients with metabolic acidosis;
- In patients suffering from renal failure;
- In patients with Prinzmetal angina;
- In patients with pheochromocytoma not treated with β-blockers;
- In patients already on verapamil or diltiazem therapy;
- In patients with a predisposition to hypoglycemia;
- In pregnancy and during lactation.
