India · Hypertension · Angina · Arrhythmia · Post-MI · Paediatric · Aten · Tenormin · Beta-One · Atehexal
eGFR > 35: Standard dose OD
eGFR 15–35: 50 mg every 48 hours (alternate day)
eGFR < 15 / dialysis: 25–50 mg after each dialysis session
⚠️ Atenolol accumulates in CKD — significant bradycardia risk at standard doses
Atenolol is a cardioselective beta-1 adrenergic receptor blocker widely used in India for hypertension, angina pectoris, arrhythmias, and post-myocardial infarction secondary prevention. Its cardioselectivity (predominantly blocks β1 receptors in the heart, with less β2 blockade in bronchi) gives it an advantage over non-selective beta-blockers in patients with mild airways disease — though it remains contraindicated in significant asthma and COPD with bronchospasm. Atenolol is predominantly renally excreted (85%) and requires dose adjustment in CKD — unlike many other antihypertensives.
Abrupt discontinuation of atenolol (and all beta-blockers) in patients with ischaemic heart disease or angina can precipitate rebound tachycardia, hypertension, worsening angina, and acute MI. This occurs because chronic beta-blockade upregulates cardiac β-adrenergic receptors — sudden removal of the blocker causes excessive catecholamine response. Atenolol must always be tapered over a minimum of 2 weeks (and preferably 4 weeks) before stopping. Reduce the dose gradually: 100mg → 50mg × 2 weeks → 25mg × 2 weeks → stop. If urgent stopping is required (surgery, adverse effect), closely monitor for rebound symptoms.
Despite being cardioselective, atenolol retains sufficient β2 activity at higher doses to cause clinically significant bronchospasm in patients with asthma or significant COPD. Even at standard doses (50–100 mg), atenolol can precipitate acute bronchospasm in asthmatics. Atenolol is contraindicated in asthma and in COPD with a significant reversible (bronchospastic) component. For hypertension in asthmatic or COPD patients, use amlodipine, telmisartan, or ramipril instead. If a beta-blocker is genuinely required (post-MI, heart failure), use bisoprolol at the lowest effective dose under specialist supervision with respiratory monitoring.
Atenolol is ~85% renally excreted unchanged. In CKD, it accumulates causing progressive bradycardia, hypotension, and fatigue. At eGFR 15–35: reduce to 50 mg every 48 hours. At eGFR <15 or on dialysis: 25–50 mg after each haemodialysis session (atenolol is dialysable). This dose adjustment is frequently missed in Indian clinical practice — check eGFR at initiation and annually. Many patients with hypertension-related CKD are on standard once-daily atenolol doses despite significantly impaired renal function, resulting in progressive bradycardia and falls.