Propranolol is a nonselective Beta-1 and Beta-2 antagonist (Beta blocker), used for cardiac conditions as an antianginal, antiarrhythmic, or antihypertensive. It is also used for non-cardiac purposes such as migraines and tremors.

Indications for Use

Propranolol is used to treat cardiovascular conditions such as high blood pressure and various cardiac conditions or dysrhythmias. For chronic stable angina, it will decrease the frequency and increase exercise tolerance. It will control supraventricular arrhythmias (eg, atrial fibrillation and flutter, atrioventricular nodal re-entrant tachycardia) and ventricular tachycardias, resulting in lower heart rate and slower contractility.

It is also used after a myocardial infarction to reduce mortality by decreasing heart workload. Beta-blockers prevent remodeling of the heart after an ischemic event by reducing the effects of catecholamines on cardiac tissue (Chen, Galuska & Hamilton, 2023).

For non-cardiovascular uses, propranolol is used for migraine prophylaxis, restless leg syndrome and essential tremor. Propranolol is also used off label for performance anxiety with symptoms of tachycardia, sweating and flushing secondary to the activation of the sympathetic nervous system (Shahrokhi & Gupta, 2023).

Mechanism of Action

Propranolol is a nonselective competitive beta-adrenergic receptor antagonist resulting in the inhibition of both Beta-1 receptors in the heart and Beta-2 receptors in the pulmonary and vascular smooth muscle.

Beta-1 receptors are located on the cardiac myocytes, including sinoatrial and atrioventricular (AV) nodes. When beta-1 is blocked, there is a slowing of the heart rate (negative chronotropic effect), a decreased conduction through AV node and a decreased myocardial contractility.  Beta-2 receptors are located in the pulmonary and vascular smooth muscle. When beta-2 is blocked, blood pressure is lowered through inhibiting sympathetic nervous system stimulation.

For migraine suppression, the mechanism of action is less clear. Its use for migraine treatment was discovered accidently. It is possibly due to reducing trigeminal nerve stimulation in the brain, and suppressing cortical spreading depression to lower the migraine attack threshold (Versijpt, Deligianni, Hussain, et al., 2024).

For tremor management, the proposed mechanism of action is by blocking peripheral noncardiac beta-2 receptors located in muscles (Frei & Truong, 2022).

Nursing Considerations

Administration: Oral (immediate release and extended release) available, take on an empty stomach. Do not crush extended-release formulations.

• Propranolol is readily absorbed with oral administration. For immediate release tablets, peak effects is within one to two hours.
• IV: slow infusion with continuous telemetry. Monitor blood pressure and heart rate during infusion.

Assessment and Monitoring

• Check blood pressure and apical pulse before giving drug; withhold and notify prescriber if apical pulse is less than 60 beats per minute or systolic blood pressure is less than 100 mm Hg, unless other parameters are provided.
• Can mask symptoms of hypoglycemia in diabetics.

Use with caution with clients who have co-existing asthma or chronic obstructive pulmonary disease (COPD) because of the effects on Beta-2 receptors that could potentially cause bronchoconstriction.

Use with caution in clients with impaired hepatic or renal function. Dosages likely lowered.

Drug Interactions

Propranolol can interact with many medications, so a thorough medication profile is warranted. There are numerous drug interactions, including aluminum- based antacid, cholestyramine, warfarin, corticosteroids, and NSAIDs.

• Aluminum based antacids and cholestyramine or colestipol (lipid lowering medications) can decrease propranolol’s absorption. Do not take these meds at the same time as propranolol.
• NSAIDs can decrease effectiveness of propranolol in lowering blood pressure. Monitor BP more frequently.
• Propranolol inhibits P450 enzymes (CYP2C9) in the liver. CYP2C9 is responsible for warfarin metabolism, is if inhibited, warfarin clearance is reduced, leading to increased warfarin levels in the blood, and higher risk of bleeding. Check INR more frequently.
• Corticosteroids, such as prednisone, can decrease the blood pressure lowering effects of propranolol. This is due to the sodium and water retention effects of prednisone, primarily seen if taking for more than a week. Monitor BP and weight.

Cautious use or avoid taking propranolol with other meds that lower heart rate, including calcium channel blockers.

Adverse/Side Effects

With IV administration, the most serious adverse effects include bronchoconstriction, hypotension, bradycardia, and signs of worsening heart failure.

Side effects include:

• CNS: drowsiness, fatigue, and cold extremities.
• CVS/ Resp: bradycardia, wheezing/bronchospasms
• Other: gastrointestinal issues, abdominal pain, nausea, erectile dysfunction,

Propranolol is safe to give to pediatric clients, with dose adjustments made according to response to medication

Safety Warning: Abrupt withdrawal of this drug may cause exacerbation of angina or a myocardial infarction. To discontinue this drug, gradually reduce dosage over 1 to 2 weeks.

Propranolol is highly lipophilic, so if overdosed, can lead to seizures. Glucagon can be administered to reverse beta-blocker overdose effects, increasing heart rate, and myocardial contractility (Shahrokhi, M & Gupta, V. 2023).

Client Teaching

• Clients should be instructed to follow the medication dosing regimen.
• Stopping medication therapy abruptly may cause life-threatening arrhythmias. Dosages will be tapered.
• Monitor pulse and blood pressure to evaluate medication effectiveness.
• May cause orthostatic blood pressure changes and increased sensitivity to cold

(Shahrokhi & Gupta, 2023).

Propranolol Medication Card

Now let’s take a closer look at the medication Card for propranolol (Shahrokhi & Gupta, 2023). Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication.Downloadable file (.docx): Propranolol Medication Card

Interactive Activity

References

• Chen, R., Galuska, M. & Hamilton, R. (2023). Beta-blocker Toxicity. National Library of Medicine. Stat Pearls (Internet). https://www.ncbi.nlm.nih.gov/books/NBK448097/
• Frei, K. & Truong, D. (2022). Medications used to treat tremors. Journal of the Neurological Sciences, 435. 120194.  https://doi.org/10.1016/j.jns.2022.120194
• Shahrokhi, M. & Gupta, V. (2023). Propranolol. National Library of Medicine.  https://www.ncbi.nlm.nih.gov/books/NBK557801/
• uCentral from Unbound medicine. https://www.unboundmedicine.com/ucentral
• Versijpt, J., Deligianni, C., Hussain, M. et al. (2024). European Headache Federation (EHF) critical re-appraisal and meta-analysis of oral drugs in migraine prevention – part 4: propranolol. J Headache Pain 25, 119. https://doi.org/10.1186/s10194-024-01826-y
• Wang, D.W., Mistry, A., Kahlig, K., Kearney, J., Xiang J., George, A. (2010). Propranolol blocks cardiac and neuronal voltage-gated sodium channels. Frontier Pharmacology, 1 (144). PubMed.