Propranolol (Inderal)

Class

Non-selective beta-adrenergic blocker

Mechanism

Propranolol blocks β1- and β2-adrenergic receptors, reducing sympathetic nervous system activity. This leads to decreased heart rate, blood pressure, and tremor amplitude, making it useful for both cardiovascular and psychogenic symptoms of anxiety.

FDA-Approved Use

Hypertension, performance anxiety, essential tremor, migraine prophylaxis, atrial arrhythmias, and angina

Off-Label Use

Generalized anxiety disorder (GAD), post-traumatic stress disorder (PTSD), lithium-induced tremor, autonomic hyperactivity in psychiatric or neurologic conditions, agitation and aggression in traumatic brain injury (TBI), post-stroke aggression

Formulation

Oral tablet (immediate- and extended-release), oral solution, IV formulation

Titration

For situational anxiety, start at 10–20 mg p.o. 1–2 hours before the event; for regular use, start at 20–40 mg p.o. BID, titrated as needed

Dose Range

10–40 mg PRN situationally; 40–160 mg/day in divided doses for chronic use

Kinetics

Half-life 3–6 hours (longer in extended-release form); metabolized by the liver (CYP2D6); crosses the blood-brain barrier

Common AEs

Bradycardia, hypotension, fatigue, dizziness, cold extremities, and vivid dreams

Serious/Rare AEs

Bronchospasm (especially in asthma), depression, heart block, and hypoglycemia (particularly in children or diabetics)

Monitoring

Monitor blood pressure, heart rate, and signs of orthostatic hypotension, particularly in elderly or those with cardiac comorbidities

Black Box Warning

Abrupt discontinuation can lead to severe angina exacerbation, myocardial infarction, and ventricular arrhythmias in patients with coronary artery disease

Considerations

Propranolol may be useful in Parkinson’s disease (PD) for treating comorbid anxiety and tremor symptoms. It may also help modulate behavioral agitation in dementia, particularly when autonomic arousal or performance-related distress is evident. Use with caution in older adults due to risks of bradycardia, hypotension, and orthostasis, all of which may increase fall risk. Avoid in patients with asthma, significant conduction abnormalities, or poorly controlled diabetes without careful monitoring.