Among the following beta blockers, which is the most commonly used agent for hypertension and angina management in India due to its cardioselective properties and oral bioavailability?

Explanation

## Most Commonly Used Beta Blocker in India **Key Point:** Atenolol is the most frequently prescribed beta blocker in India for hypertension and angina due to its cardioselective (β₁-selective) properties, predictable pharmacokinetics, and cost-effectiveness. ### Why Atenolol Is Most Common 1. **Cardioselective (β₁-selective):** Minimal effect on β₂-receptors in bronchi and blood vessels 2. **Hydrophilic:** Poor CNS penetration → fewer neuropsychiatric side effects (less fatigue, depression, nightmares) 3. **Oral bioavailability:** 40–50%, reliable and predictable 4. **Long half-life:** 6–7 hours → once-daily dosing improves compliance 5. **Renal excretion:** Minimal hepatic metabolism → fewer drug interactions 6. **Cost-effective:** Generic formulations widely available in India 7. **Established safety profile:** Decades of clinical use; extensive evidence base ### Comparison of Common Beta Blockers | Agent | Selectivity | Lipophilicity | CNS Effects | Half-life | Dosing | Common Use | |---|---|---|---|---|---|---| | **Atenolol** | β₁-selective | Hydrophilic | Minimal | 6–7 h | Once daily | **Most common** | | Propranolol | Non-selective | Lipophilic | Significant | 3–6 h | 2–3 times daily | Anxiety, tremor, migraine | | Labetalol | Non-selective + α-block | Moderate | Moderate | 5–8 h | 2–3 times daily | Hypertensive crisis, pregnancy | | Carvedilol | Non-selective + α-block | Lipophilic | Moderate | 7–10 h | Twice daily | Heart failure, post-MI | **High-Yield:** Atenolol is the **first-line beta blocker** for hypertension and stable angina in India because it combines cardioselectivity (safety in airway disease) with hydrophilicity (fewer CNS effects) and once-daily dosing (better compliance). ### Why Other Options Are Less Common **Propranolol:** - Non-selective → risk of bronchospasm in asthma/COPD - Lipophilic → crosses blood–brain barrier → fatigue, depression, nightmares, sexual dysfunction - Short half-life → requires 2–3 times daily dosing → poor compliance - Used preferentially for anxiety, tremor, migraine (not first-line for hypertension) **Labetalol:** - Combined α and β blockade → more complex pharmacology - Primarily used for hypertensive emergencies and pregnancy, not routine hypertension - More expensive than atenolol **Carvedilol:** - Non-selective with α-blocking properties → more side effects - Primarily indicated for heart failure and post-MI, not first-line for hypertension - Twice-daily dosing → worse compliance than atenolol - More expensive **Clinical Pearl:** Atenolol is preferred in patients with asthma or COPD (relative contraindication to non-selective beta blockers) because its β₁-selectivity at therapeutic doses minimizes airway obstruction. **Mnemonic:** **CHEAP** — Cardioselective, Hydrophilic, Easy dosing (once daily), Affordable, Predictable pharmacokinetics → **Atenolol** [cite:KD Tripathi 8e Ch 12]