Beta-Blockers Pregnancy: Caution should be exercised during pregnancy. Crosses the placental barrier; possibility of foetal injury cannot be excluded (no first-trimester studies); associated with intra-uterine growth retardation. Anticipated benefit must be weighed against possible risks, particularly in first and second trimesters. Breast-feeding: significant accumulation in breast milk; neonates may be at risk of hypoglycaemia and bradycardia.

Atenolol

Brand names: Tenormin

Atenolol is a cardioselective beta-blocker used for angina, arrhythmias, hypertension and after myocardial infarction.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Hypertension: 100 mg once daily orally (some patients respond to 50 mg once daily). Angina: 100 mg once daily orally or 50 mg twice daily.

Route: Oral (also intravenous for cardiac arrhythmias and myocardial infarction)

Frequency: Once daily (angina alternatively twice daily)

The dose must always be adjusted to individual requirements, with the lowest possible starting dose. HYPERTENSION: most patients respond to 100 mg once daily; some respond to 50 mg once daily; effect fully established after one to two weeks. ANGINA: 100 mg once daily or 50 mg twice daily (unlikely to gain additional benefit from higher doses). CARDIAC ARRHYTHMIAS: initial dose 2.5 mg IV over 2.5 minutes (1 mg/minute), repeated at 5-minute intervals until response up to a maximum of 10 mg; or by infusion 0.15 mg/kg over 20 minutes; oral maintenance 50-100 mg daily as a single dose. MYOCARDIAL INFARCTION (within 12 hours of chest pain onset): atenolol 5-10 mg by slow IV injection (1 mg/minute), then 50 mg orally ~15 minutes later, a further 50 mg orally 12 hours after the IV dose, then 100 mg orally once daily. Elderly: dosage requirements may be reduced, especially with impaired renal function.

Dose adjustments

Renal

Dosage should be adjusted in severe renal impairment. CrCl 15-35 mL/min/1.73m2: oral 50 mg daily (IV 10 mg every two days). CrCl <15 mL/min/1.73m2: oral 25 mg daily or 50 mg on alternate days (IV 10 mg every four days). Haemodialysis: 50 mg orally after each dialysis under hospital supervision.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION Hypertension The initial dose of atenolol is 50 mg given as one tablet a day either alone or added to diuretic therapy. The full effect of this dose will usually be seen within one to two weeks. If an optimal response is not achieved, the dosage should be increased to atenolol 100 mg given as one tablet a day. Increasing the dosage beyond 100 mg a day is unlikely to produce any further benefit. Atenolol may be used alone or concomitantly with other antihypertensive agents including thiazide-type diuretics, hydralazine, prazosin, and alpha-methyldopa. Angina Pectoris The initial dose of atenolol is 50 mg given as one tablet a day. If an optimal response is not …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-11-26. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Cardiogenic shock
Uncontrolled heart failure
Sick sinus syndrome
Second- or third-degree heart block
Untreated phaeochromocytoma
Metabolic acidosis
Bradycardia (<45 bpm)
Hypotension
Severe peripheral arterial circulatory disturbances

Side effects

Bradycardia (common)
Cold extremities (common)
Gastrointestinal disturbances (common); fatigue (common)
Postural hypotension which may be associated with syncope (rare); Raynaud's phenomenon (rare)
Sleep disturbances (uncommon); dizziness, headache, paraesthesia (rare); bronchospasm in patients with asthma or history of asthmatic complaints (rare)

Interactions

Should not be withdrawn abruptly (withdraw gradually over 7-14 days)
Caution in patients with first-degree heart block (negative effect on conduction time)
May mask symptoms of hypoglycaemia (particularly tachycardia) and signs of thyrotoxicosis
May cause a more severe reaction to allergens; such patients may be unresponsive to usual doses of adrenaline (epinephrine)
Avoid in reversible obstructive airways disease unless compelling clinical reasons (use with caution)

Clinical monograph

How it works

It selectively blocks β1-adrenoceptors, reducing heart rate, contractility and myocardial oxygen demand.

Prescribing in practice

It is renally cleared — reduce the dose in renal impairment.
Do not stop abruptly in ischaemic heart disease; use caution in asthma; it can mask hypoglycaemia.
It is no longer a preferred first-line antihypertensive, being reserved for specific indications.

Monitoring

Monitor heart rate and blood pressure and the response for the indication.

Counselling the patient

Do not stop it suddenly.
Tiredness, cold hands or a slow pulse can occur.
Report wheeze or marked dizziness.

Evidence & guidelines

Used for angina, arrhythmia and post-MI; not first-line for uncomplicated hypertension in current guidance (NICE NG136).

Reference: LIFE trial Lancet 2002; 359(9311):995-1003; ISIS-1 Lancet 1986; 2(8498):57-66; ESC Hypertension Guidelines 2018; MHRA SPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways