Atenolol

Registered South African indications:

• Hypertension - mild to moderate
• Angina pectoris

Contraindications

South African recommendations

• Hypersensitivity to the active ingredient or any of its excipients
• Cardiogenic shock
• Second and third-degree heart block 
• Bradycardia less than 50 beats/minute
• Metabolic acidosis
• Severe peripheral arterial circulatory disturbances
• Raynaud’s phenomenon
• Sick sinus syndrome
• Untreated phaeochromocytoma
• Hypotension
• After prolonged fasting
• Cardiac failure (unless or until signs of failure are controlled with digitalis or diuretics)
• Beta-blockers should be avoided in uncontrolled heart failure because of their negative inotropic effects, excluding that due to hypertrophic obstructive cardiomyopathy
• Particular caution should be exercised with patients suffering from the following
  - Asthma
  - Bronchitis
  - Chronic respiratory diseases
  - Reversible obstructive airways disease (unless there are compelling clinical reasons for their use)
• Reduction in dosage to which patient is accustomed to in the perioperative period
• A patient's normal tachycardic response to hypovolemia or blood loss may be obscured during or after surgery. Particular caution should be taken in this regard

Recommendations in other jurisdictions 

• Hypersensitivity to the active ingredient or any of its 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

Cautions

• Pregnancy
• Breastfeeding
• Severe renal impairment
• Elderly
• Abrupt withdrawal
• Surgery
• Poor cardiac reserve
• Prinzmetal's angina
• Raynaud's disease/syndrome (Recommendations in other jurisdictions)
• Intermittent claudication
• 1st degree heart block
• Diabetes mellitus
• Thyrotoxicosis
• Psoriasis

Forms avail. in SA and covered in this monograph: fct, tab

Dosages below include:

• South African registered indications and dosages
• Indications and dosages registered in other jurisdictions

South African registered indications and dosages

Hypertension - mild to moderate (Additional agent(s) may be required)

• Oral (fct, tab): 50-100mg, dly as a single dose 

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Additional doses are unlikely to be of any benefit

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Atenolol may be combined with diuretics or other antihypertensive agents to achieve a further reduction in blood pressure

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Angina pectoris

• Oral (fct, tab): 50-100mg, dly as a single dose OR in divided doses

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Indications and dosages registered in other jurisdictions

Hypertension (Additional agent(s) may be required)

• Oral (tab): 50-100mg, dly as a single dose

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Most patients respond to 100mg daily given as a single dose. Some patients, however, will respond to 50mg given as a single daily dose. The effect will be fully established after 1-2 weeks

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A further reduction in blood pressure may be achieved by combining atenolol with other antihypertensive agents. For example, co-administration of atenolol with a diuretic provides a highly effective and convenient antihypertensive therapy

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Angina pectoris

• Oral (tab): 100mg, dly OR 50mg, 12hrly

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It is unlikely that additional benefit will be gained by increasing the dose

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Cardiac arrhythmias
- As a maintenance dose after having controlled the dysrhythmias with intravenous atenolol

• Oral (tab): 50-100mg, dly as a single dose

Myocardial infarction
- Early intervention in the acute phase for patients suitable for treatment with intravenous beta-blockade and presenting within 12hrs of the onset of chest pain

• Oral (tab): 15min after the administration of the IV dose: 50mg, may be given (provided that no untoward effects occur from the IV dose); Follow on dose: 50mg, 12hrs after IV dose; Then 12hrs later: 100mg, dly

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If bradycardia and/or hypotension requiring treatment, or any other untoward effects occur, atenolol should be discontinued

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For all indications: The dose must always be adjusted to individual requirements of the patients, with the lowest possible starting dosage

Not established for use in children

Pregnancy

• Caution; positive evidence of risk
• Atenolol crosses the placental barrier and appears in the cord blood. No studies have been performed on the use of atenolol in the first trimester and the possibility of foetal injury cannot be excluded. Atenolol has been used under close supervision for the treatment of hypertension in the third trimester. Administration of atenolol to pregnant women in the management of mild to moderate hypertension has been associated with intra-uterine growth retardation
• The use of atenolol in women who are, or may become, pregnant requires that the anticipated benefit be weighed against the possible risks, particularly in the first and second trimesters, since beta-blockers, in general, have been associated with a decrease in placental perfusion which may result in intra-uterine deaths, immature and premature deliveries

Breastfeeding

• Caution 

• There is a significant accumulation of atenolol in breast milk. Neonates born to mothers who are receiving atenolol at parturition or breastfeeding may be at risk of hypoglycaemia and bradycardia

Renal Impairment

• Mild to moderate: No dose adjustment recommended
• Severe: Caution; dose adjustment recommended

CrCl (ml/min)	Adults
>35	No adjustment necessary
15-35	Oral (tab): 50mg, dly; Inj (IV) 10mg once every 2 days
<15	Oral (tab): 25mg, dly; Inj (IV) 10mg once every 4 days
Haemodialysis	Oral (tab): 50mg, dly; after dialysis

Hepatic Impairment

• No dose adjustment recommended

Elderly

• Caution; dose adjustment recommended
  Elderly with no cardiac or renal co-morbidities: Max: 50mg/24hrs 
  Elderly with eGFR ≤30 ml/min/1.73m²: Limit the daily intake to 1mg/kg/dose, 48hrly
  Diastolic Blood Pressure (<60mmHg): Contraindicated

Porphyria Information

• Not porphyrinogenic (NP)

Drugs in Sport

• Prohibited - In certain sports
  
  Prohibited - In and out of competition:
  Archery (WA)
  Shooting (ISSF) (IPC)
  
  Prohibited - In competition:
  Automobile (FIA)
  Billiards (all disciplines) (WCBS)
  Darts (WDF)
  Golf (IGF)
  Skiing / Snowboarding (FIS) in ski jumping, freestyle aerials/halfpipe and snowboard halfpipe/big air
  Underwater sports (CMAS) in constant-weight apnoea with or without fins, dynamic apnoea with and without fins, free immersion apnoea, Jump Blue apnoea, spearfishing, static apnoea, target shooting and variable weight apnoea

Central Nervous System Disorders

• Sleep disturbances
• Nightmares
• Depression
• Confusion
• Headache
• Seizure
• Hallucinations
• Psychoses
• Memory loss
• Dizziness
• Paraesthesia
• Myasthenia gravis like syndrome

Cardiovascular Disorders

• Bradycardia
• Heart failure deterioration
• Precipitation of heart block
• Postural hypotension
• Syncope
• Worsening of angina pectoris
• Cold extremities
• Raynaud's syndrome
• Exacerbation of intermittent claudication

Respiratory Disorders

• Bronchospasm
• Dyspnoea

Gastrointestinal Disorders

• Diarrhoea
• Nausea and vomiting
• Constipation
• Dry mouth

Genitourinary Disorders

• Reduced renal blood flow
• Reduced glomerular filtration rate
• Sexual dysfunction

Endocrine and Metabolic Disorders

• Hypoglycaemia
• Changes in lipid metabolism

Musculoskeletal Disorders

• Arthralgia

Skin and Subcutaneous Tissue Disorders

• Alopecia
• Purpura
• Psoriasiform skin reactions
• Exacerbation of psoriasis
• Rash

Immune, Blood and Lymphatic System Disorders

• Thrombocytopenia
• Agranulocytosis
• Increased antinuclear antibody

Sensory Disorders

• Visual disturbances
• Dry eyes
• Conjunctivitis

Others

• Fatigue

• Calcium channel blockers
• Digoxin
• Clonidine
• Class I antiarrhythmics
• Sympathomimetics
• Antidiabetic agents
• Prostaglandin synthetase inhibitors
• Anaesthetic agents
• Monoamine oxidase inhibitors
• Baclofen
• Iodated contrast media
• Amiodarone
• Ampicillin
• Muscle relaxants
• Dihydropyridines

None routine

Atenolol is a beta-blocker, which acts preferentially on beta1-adrenergic receptors in the heart. It has negative inotropic effects resulting in reduction in heart rate, myocardial contractility, impulse conduction rate and adrenergic-induced renin release. As with other beta-blockers, the mode of action of atenolol in the treatment of hypertension is unclear.  

Tablet 25mg

• Tenopress (Austell)
• Tenormin (AstraZeneca) originator

Tablet 50mg

• Adco-Atenolol (Adcock)
• B-Block (Ranbaxy)
• Bio-Atenolol (Biotech)
• Gulf Atenolol fct (Gulf Drug) 
• Hexa-Blok (Sandoz)
• Ten-Bloka (Pharmacare)
• Sandoz Atenolol (Sandoz)
• Tenopress (Austell)
• Tenormin (AstraZeneca) originator
• Zetenol (Dezzo Trading)

Tablet 100mg

• Adco-Atenolol (Adcock)
• B-Block (Be-Tabs)
• Bio-Atenolol (Biotech)
• Gulf Atenolol fct (Gulf Drug) 
• Hexa-Blok (Sandoz)
• Sandoz Atenolol (Sandoz)
• Ten-Bloka (Pharmacare)
• Tenopress (Austell)
• Tenormin (AstraZeneca) originator
• Zetenol (Dezzo Trading)