Atenolol + chlortalidone

Full Generic Medicine Info
Dosage/Direction for Use

Adult: Available preparations: Atenolol 50 mg and chlortalidone 12.5 mg tab Atenolol 50 mg and chlortalidone 25 mg tab Atenolol 100 mg and chlortalidone 25 mg tab In patients who do not adequately respond to monotherapy: Initially, 1 tab of 50 mg atenolol/25 mg chlortalidone once daily, may increase to 1 tab of 100 mg atenolol/25 mg chlortalidone once daily if the optimal blood pressure response is not achieved. Individualise dosage.
Elderly: Initiate at lower doses.
Renal impairment:
CrCl (ml/min)Dosage Recommendation
<15Max dose of atenolol component: 50 mg every other day.
15-35Max dose of atenolol component: 50 mg once daily.
Hypersensitivity to atenolol, chlortalidone or sulfonamide derivatives. Sick sinus syndrome, bradycardia, 2nd- or 3rd-degree heart block, cardiogenic shock, hypotension, overt cardiac failure, severe peripheral arterial circulatory disorders, uncontrolled heart failure, anuria, metabolic acidosis, untreated phaeochromocytoma.
Special Precautions
Patient with history of severe anaphylaxis to allergens; bronchospastic disease, bronchial asthma, COPD, conduction abnormality, left ventricular dysfunction, 1st-degree heart block, controlled heart failure, Prinzmetal's angina, cerebrovascular disease; prediabetes or diabetes mellitus, history of gout, hypercholesterolaemia, myasthenia gravis, peripheral vascular disease (e.g. intermittent claudication), Raynaud's disease, psoriasis, thyroid disease, cirrhosis. Patient undergoing major surgery. Avoid abrupt withdrawal (particularly in patients with coronary artery disease). Renal and hepatic impairment. Elderly. Pregnancy and lactation. Patient Counselling This drug may cause dizziness, if affected, do not drive or operate machinery. Avoid excessive exposure to sunlight or UV light. Monitoring Parameters Monitor blood pressure, heart rate, fluid and electrolyte balance, and renal function tests regularly during treatment. Observe for symptoms of gout, fluid or electrolyte imbalance; worsening of heart failure (in at-risk patients).
Adverse Reactions
Significant: Hypersensitivity reactions (e.g. angioedema, urticaria), bradycardia, electrolyte disturbances (e.g. hypokalaemia, hypochloraemic alkalosis, hyponatraemia), bronchospasm, masked warning signs of hypoglycaemia or hyperthyroidism (e.g. tachycardia); activation or exacerbation of SLE, precipitation of gout or azotaemia, hyperuricaemia, photosensitivity. Ear and labyrinth disorders: Vertigo. Gastrointestinal disorders: Nausea, diarrhoea, gastrointestinal disturbance. General disorders and administration site conditions: Fatigue, lethargy. Investigations: Transaminase level elevations. Metabolism and nutrition disorders: Impaired glucose tolerance. Musculoskeletal and connective tissue disorders: Muscle fatigue. Nervous system disorders: Dizziness, drowsiness, headache. Psychiatric disorders: Sleep disturbances, depression. Respiratory, thoracic and mediastinal disorders: Wheezing, dyspnoea. Skin and subcutaneous tissue disorders: Rarely, rash, exacerbated psoriasis. Vascular disorders: Cold extremities, orthostatic hypotension.
Symptoms: Lethargy, wheezing, sinus pause, bradycardia, hypotension, CHF, bronchospasm, hypoglycaemia; nausea, weakness, dizziness and electrolyte balance disturbance. Management: Symptomatic and supportive treatment. Perform gastric lavage, administer activated charcoal or induce emesis to remove any unabsorbed drug. May give atropine or glucagon IV bolus for bradycardia; isoproterenol or transvenous pacemaker for 2nd- or 3rd-degree heart block; vasopressors (e.g. dopamine, norepinephrine) or dobutamine for hypotension; β<290>2<190>-stimulants (e.g. isoproterenol, terbutaline, aminophylline) for bronchospasm; IV glucose for hypoglycaemia. May administer digitalis and diuretic for CHF. Initiate measures to maintain hydration and electrolytes. Monitor blood pressure, electrolyte levels and renal function. Atenolol may be removed by haemodialysis, if necessary.
Drug Interactions
May increase the atrioventricular conduction time or cause arrhythmias with digitalis glycosides. Antihypertensive effect may be enhanced by baclofen. May reduce the hypotensive and diuretic effects with NSAIDs (e.g. ibuprofen, indometacin). Atenolol: May increase risk of postural hypotension with α-blockers (e.g. prazosin, alfuzosin). May diminish reflex tachycardia and increase the risk of hypotension with anaesthetic drugs. May enhance the bradycardic effect with disopyramide and amiodarone. May intensify blood sugar-lowering effects and mask signs of hypoglycaemia with insulin and oral antidiabetics. May cause severe hypotension, bradycardia and cardiac failure with Ca channel blockers (e.g. nifedipine, diltiazem, verapamil). Increased risk of rebound hypertension after the withdrawal of clonidine. May antagonise effects with sympathomimetic agents (e.g. epinephrine). Ampicillin may decrease the bioavailability of atenolol. Chlortalidone: May decrease the renal clearance resulting in increased serum levels of lithium. May potentiate the action of antihypertensives (e.g. ACE inhibitors). May potentiate hypokalaemic effects with corticosteroids, β2-agonists, amphotericin B. May increase bioavailability with anticholinergic agents (e.g. atropine, biperiden). May reduce absorption with colestyramine. May increase risk of hypersensitivity reactions to with allopurinol. May enhance the hypotensive effect with diazoxide. May reduce renal excretion and potentiate myelosuppressive effects of antineoplastic agents (e.g. cyclophosphamide, methotrexate). May decrease the excretion and increase the effects of Ca salts and vitamin D.
Food Interaction
Chlortalidone: Enhanced orthostatic hypotensive effects with alcohol.
Lab Interference
May result in false-positive aldosterone/renin ratio (ARR). Chlortalidone may reduce the serum protein-bound iodine (with no signs of thyroid disturbance).
Atenolol and chlortalidone combination results in additive antihypertensive action. Atenolol, a β-blocker, selectively and competitively inhibits the response on the β1-adrenergic receptors in the heart. Chlortalidone is a sulfonamide-derived thiazide-like diuretic that reduces blood pressure by inhibiting Na and chloride reabsorption in the distal convoluted tubule. Synonym: Chlortalidone: chlorthalidone.
Onset: Atenolol: β-blocking effect: ≤1 hour. Chlortalidone: Diuretic effect: Approx 2.6 hours.
Duration: Atenolol: β-blocking effect: 12-24 hours; antihypertensive effect: 24 hours. Chlortalidone: 24-48 hours (single dose); 48-72 hours (long-term dosing).
Absorption: Atenolol: Rapid and consistent but incompletely absorbed (approx 50%) from the gastrointestinal tract. Time to peak plasma concentration: 2-4 hours. Chlortalidone: Consistent but incompletely absorbed (approx 60%) from the gastrointestinal tract. Bioavailability: Approx 65%. Time to peak plasma concentration: Approx 12 hours.
Distribution: Atenolol: Poorly penetrates tissues due to low lipid solubility. Crosses the placenta and enters breast milk. Plasma protein binding: 6-16%. Chlortalidone: Crosses the placenta and enters breast milk. Plasma protein binding: Approx 75%, 58% to albumin.
Metabolism: Atenolol: Limited metabolism in the liver. Chlortalidone: Metabolised in the liver.
Excretion: Atenolol: Via faeces (50%); urine (40% as unchanged drug). Elimination half-life: 6-7 hours. Chlortalidone: Via urine (mainly as unchanged drug). Elimination half-life: 40 hours (single dose); 45-60 hours (long-term dosing).
Oral: Store between 20-25°C. Protect from light and moisture.
CIMS Class
ATC Classification
C03BA04 - chlortalidone ; Belongs to the class of low-ceiling sulfonamide diuretics.
C07AB03 - atenolol ; Belongs to the class of selective beta-blocking agents. Used in the treatment of cardiovascular diseases.
Disclaimer: This information is independently developed by CIMS based on atenolol + chlortalidone from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to CIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, CIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 CIMS. All rights reserved. Powered by
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