Inderal (Propranolol) 10 mg / 20 mg / 40 mg / 80 mg Tablets: Prescription Non-Selective Beta-Blocker for Hypertension, Essential Tremor, Migraine Prophylaxis, and Performance Anxiety — Not OTC, Prescription Required

Information last reviewed: May 2026 — for educational purposes only.

Propranolol is a non-selective beta-adrenergic receptor blocker that inhibits both beta-1 (cardiac) and beta-2 (pulmonary and vascular) receptors. Sold under the brand name Inderal, it is one of the oldest and most clinically versatile beta-blockers available. It is a prescription medication used across a remarkably broad range of indications beyond hypertension.

Uses of Propranolol

Propranolol is indicated for hypertension, angina pectoris, essential tremor, migraine prophylaxis, and cardiac arrhythmias. Off-label uses include performance anxiety (a widely used application), management of thyroid storm (reduces adrenergic symptoms), portal hypertension prevention of variceal bleeding, and post-myocardial infarction mortality reduction. It is used as an adjunct in pheochromocytoma treatment, but only after alpha-blockade has been established — starting propranolol before alpha-blockade can cause paradoxical hypertensive crisis. Its broad receptor blockade makes it effective across many sympathetic nervous system overdrive states.

Mechanism, Warnings, and Key Interactions

Propranolol competitively and non-selectively blocks beta-1 receptors in the heart (reducing heart rate and contractility) and beta-2 receptors in the lungs (which when blocked can trigger bronchospasm). Propranolol is contraindicated in asthma and reactive airway disease due to this beta-2 blockade. It is also contraindicated in decompensated heart failure, significant bradycardia, second- or third-degree AV block without a pacemaker, and cardiogenic shock. An important caution in insulin-dependent diabetics: propranolol masks the sympathetic signs of hypoglycaemia, particularly tachycardia and palpitations, making it harder for patients to recognise low blood sugar. Notably, diaphoresis (sweating) is mediated by the cholinergic system and is not masked. Propranolol must never be stopped abruptly in patients with coronary artery disease — abrupt withdrawal can precipitate rebound angina, MI, or severe hypertension. Peripheral vasoconstriction can worsen Raynaud's phenomenon. Fatigue and sexual dysfunction are common side effects.

Available Strengths and Formulations

Propranolol IR tablets are available in 10 mg, 20 mg, 40 mg, 60 mg, and 80 mg strengths and are taken multiple times daily. Inderal LA long-acting capsules come in 60 mg, 80 mg, 120 mg, and 160 mg for once-daily dosing. Innopran XL capsules (80 mg and 120 mg) are also long-acting and are specifically taken at bedtime, capitalising on the circadian pattern of elevated morning blood pressure and heart rate.

Pricing Overview

Generic propranolol IR and LA formulations are among the most affordable beta-blockers available. Given its age and widespread use, the generic cost is very low. Branded Inderal LA and Innopran XL carry higher costs. Contact Lucas Clinic for current pricing and formulation availability.

Frequently Asked Questions

Why is propranolol dangerous in patients with asthma?

Propranolol blocks both beta-1 and beta-2 receptors. Beta-2 receptors in the airways are responsible for bronchodilation, and blocking them promotes bronchoconstriction. In patients with asthma or reactive airway disease, this can precipitate severe bronchospasm. Selective beta-1 blockers such as metoprolol carry lower risk but still require caution in respiratory disease. Propranolol should not be used in any patient with current or recent bronchospastic disease.

How does propranolol affect blood sugar awareness in diabetics?

Propranolol blunts the adrenergic (sympathetic) symptoms of hypoglycaemia — particularly tachycardia, palpitations, and tremor — which patients with insulin-dependent diabetes rely on as warning signs of low glucose. This masking effect can delay recognition of hypoglycaemia, allowing blood sugar to fall to dangerous levels. Sweating, however, is preserved as a hypoglycaemia warning sign because it is controlled by the cholinergic nervous system. Diabetics using insulin should use propranolol only with careful monitoring.

Can propranolol really help with stage fright and performance anxiety?

Yes. Propranolol is widely used off-label for situational or performance anxiety. The physical symptoms of anxiety — rapid heart rate, trembling hands, visible flushing — are driven by sympathetic activation and are effectively blunted by beta-blockade. A low dose taken 30–60 minutes before the anxiety-provoking event can substantially reduce these physical manifestations without causing the sedation associated with benzodiazepines, leaving cognitive function intact. It does not address the underlying psychological component but is highly effective for the somatic expression of anxiety.

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