Atenolol

Tablets: 25, 50 and 100 mg. Injection: 5 mg/10 ml

Atenolol should be store at room temperature 20 C to 25 C (68 F to 77 F).

Mechanism of Action

Blocks response to beta-adrenergic stimulation; cardioselective for beta1 receptors at low doses, with little or no effect on beta2 receptors

Absorption

Bioavailability: 46-60%

Onset: Antihypertensive response, 3 hr

Duration: 12-24 hr (normal renal function)

Peak plasma time: 2-4 hr

Distribution

Protein bound: 6-16%

Vd: 50-75 L/kg

Metabolism

Metabolized to limited extent in liver

Metabolites: No clinically active metabolites

Elimination

Half-life: Children, 4.6 hr; adults, 6-7 hr; neonates, <35 hr; end-stage renal disease, 15-35 hr

Dialyzable: Yes (HD)

Excretion: Feces (50%), urine (40-50%)

Before taking atenolol,

• tell your doctor and pharmacist if you are allergic to atenolol or any other medications.
• tell your doctor if you have or have ever had asthma or other lung disease; diabetes; severe allergies; an overactive thyroid gland (hyperthyroidism); pheochromocytoma; heart failure; a slow heart rate; circulation problems; or heart or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking atenolol, call your doctor immediately.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking atenolol.
• you should know that if you have allergic reactions to different substances, your reactions may be worse while you are using atenolol, and your allergic reactions may not respond to the usual doses of injectable epinephrine.

Atenolol can cause dizziness or drowsiness. Do not drive or operate heavy machinery until you know how atenolol affects you.

Atenolol should not be taken/contraindicated if you:

• have sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure. These conditions are diagnosed by your doctor.
• have an allergy to atenolol

• Keep this medication in the container it came in, tightly closed, and out of reach of children.
• Store it at room temperature and away from excess heat and moisture (not in the bathroom). 

Hypertension

Management of hypertension; used alone or in combination with other classes of antihypertensive agents.108 109 110 111 153 154 155 156 157 158 159 171 172 173 500 501

β-Adrenergic blocking agents (β-blockers) generally not preferred for initial management of hypertension, but may be considered in patients who have a compelling indication (e.g., prior MI, ischemic heart disease, heart failure) for their use or as add-on therapy in those who do not respond adequately to the preferred drug classes (ACE inhibitors, angiotensin II receptor antagonists, calcium-channel blockers, or thiazide diuretics).237 501 502 503 504 515 523 524 527 800

Black hypertensive patients generally tend to respond better to monotherapy with calcium-channel blockers or thiazide diuretics than to β-blockers.232 259 260 500 501 504 However, diminished response to β-blockers is largely eliminated when administered concomitantly with a thiazide diuretic.500

Angina

Management of chronic stable angina pectoris.111 112

A component of the standard therapeutic measures in the management of unstable angina or non-ST-segment elevation/non-Q-wave MI†.223 224 274

MI

Secondary prevention following acute MI to reduce the risk of cardiovascular mortality.111 113 120 122 123 124 132 169 274

Supraventricular Arrhythmias

Has been used in the treatment of supraventricular tachycardia† (SVT) (e.g., atrial flutter†, junctional tachycardia†, focal atrial tachycardia†, paroxysmal supraventricular tachycardia [PSVT]†).300 301 401

Vagal maneuvers and/or IV adenosine are considered first-line interventions for acute treatment of SVT when clinically indicated; if such measures are ineffective or not feasible, may consider an IV β-adrenergic blocking agent.300 Oral β-blockers may be used for ongoing management.300 Although evidence of efficacy is limited, experts state that overall safety of β-adrenergic blockers warrants use.300

Used to slow ventricular rate in patients with atrial fibrillation† or flutter†.300 301

Ventricular Arrhythmias

β-Blockers have been used in patients with cardiac arrest precipitated by ventricular fibrillation† or pulseless VT†; however, routine administration after cardiac arrest is potentially harmful and not recommended.400

β-Blockers may be useful in the management of certain forms of polymorphic VT† (e.g., associated with acute ischemia).169 401

Vascular Headache

Prophylaxis of migraine headache†.228

Not recommended for the treatment of a migraine attack that has already started.228

Alcohol Withdrawal

Management of acute alcohol withdrawal† in conjunction with a benzodiazepine.101 229

Atenolol should not be used as monotherapy for acute alcohol withdrawal†.229 230

Contraindications

• Patients with sinus bradycardia,111 118 120 220 AV block greater than first degree,111 118 120 220 274 cardiogenic shock,111 118 120 220 overt or decompensated cardiac failure. Patients with acute MI not promptly and effectively controlled by 80 mg IV furosemide or equivalent therapy.111 118 120 220

• Do not use in patients with untreated pheochromocytoma.111 118 120

• Hypersensitivity to atenolol or any ingredient in the formulation.111 118 120 220

Warnings/Precautions

Warnings

Possible precipitation of heart failure; possible decreased exercise tolerance in patients with left ventricular dysfunction.

Initiate therapy and subsequent dosage adjustments in patients with heart failure under close medical supervision. Prior to initiation of the drug, stabilize patient on other therapy (e.g., ACE inhibitor, diuretic, and/or cardiac glycoside). Symptomatic improvement may not be evident for 2–3 months after initiating therapy.

Avoid use in patients with decompensated heart failure; use cautiously in patients with inadequate myocardial function and, if necessary, in patients with well-compensated heart failure (e.g., those controlled with ACE inhibitors, cardiac glycosides, and/or diuretics); use with extreme caution in patients with substantial cardiomegaly.

Adequate treatment (e.g., with a cardiac glycoside and/or diuretic) and close observation recommended if signs or symptoms of impending cardiac failure occur; if cardiac failure continues, discontinue therapy, gradually if possible.

Possible increased reactivity to a variety of allergens; patients may be unresponsive to usual doses of epinephrine used to treat anaphylactic reactions.111 118 120

Concomitant use may cause bradycardia, heart block, increased left ventricular and diastolic blood pressure, particularly in patients with preexisting conduction abnormalities or left ventricular dysfunction.111 120 (See Specific Drugs under Interactions.)

Possible bronchoconstriction, especially at dosages >100 mg daily.c Cautious use recommended in patients with bronchospastic disease (patients who do not respond to or cannot tolerate other hypotensive agents).111 120

Initiate therapy with 50 mg daily and use lowest possible dosage; β1-selectivity is not absolute.111 120 Twice-daily dosing and concomitant use of a β2-adrenergic agonist bronchodilator may minimize risk of bronchospasm.111 120 c

If bronchospasm occurs, reduce dosage or discontinue atenolol (gradually if possible) and administer supportive treatment.111 120 c

Possible increased risks associated with general anesthesia.111 (See Specific Drugs under Interactions.)

Withdrawal of β-blocker prior to surgery is not recommended in most patients.111

Correct vagal dominance (if any) with atropine (1–2 mg IV).111

Atenolol effects can be reversed by cautious administration of β-agonists (e.g., dobutamine, isoproterenol).111 120

Possible decreased signs and symptoms of hypoglycemia, particularly tachycardia.111 120

β1-Selective atenolol does not potentiate insulin-induced hypoglycemia or delay recovery of blood glucose to normal levels.111 120

Signs of hyperthyroidism (e.g., tachycardia) may be masked.111 120

Possible thyroid storm if therapy is abruptly withdrawn; carefully monitor patients having or suspected of developing thyrotoxicosis.111 120

General Precautions

May be aggravated.111 118 120

Atenolol shares the toxic potentials of β-blockers; observe usual precautions of these agents.c

When used in fixed combination with chlorthalidone, consider the cautions, precautions, and contraindications associated with thiazide diuretics.115 116 117 118

Specific Populations

Category D.111 118 120

Distributed into milk;103 107 111 118 120 125 129 caution if used in nursing women.111 118 120 151

Safety and efficacy remain to be fully established in children;111 118 120 however, some experts have recommended dosages for hypertension based on current limited clinical experience.258

Response in patients ≥65 years of age does not appear to differ from that in younger adults; however, use with caution due to greater frequency of decreased hepatic, renal, and/or cardiac function and of concomitant disease and drug therapy observed in the elderly.111 118 120

Consider age-related decreases in renal function when selecting dosage and adjust dosage if necessary.111 Evaluation of geriatric patients with hypertension or MI should always include assessment of renal function.111 120 (See Geriatric Patients under Dosage and Administration.)

Decreased clearance; use with caution and adjust dosage based on degree of renal impairment.111 120 (See Renal Impairment under Dosage and Administration.)

Common Adverse Effects

Tiredness,111 120 hypotension,111 120 heart failure,111 120 bradycardia,111 113 120 124 ventricular tachycardia,111 120 dizziness,111 120 cold extremities,111 120 depression,111 120 supraventricular tachycardia (atrial fibrillation or flutter),111 120 bundle branch block and major axis deviation,111 120 fatigue,111 120 dyspnea.111 120

• Inhibits response to adrenergic stimuli by competitively blocking β1-adrenergic receptors within the myocardium.c Blocks β2-adrenergic receptors within bronchial and vascular smooth muscle only in high doses (e.g., >100 mg daily).c

• Decreases resting and exercise-stimulated heart rate and reflex orthostatic tachycardia by about 25–35%.c Slows AV nodal conduction.c

• No intrinsic sympathomimetic activity and little or no membrane-stabilizing effect on the heart.c

• Reduces BP by decreasing cardiac output, suppressing renin release, and/or decreasing sympathetic outflow from the CNS.c

• In patients with angina pectoris, blocks catecholamine-induced increases in heart rate, myocardial contractility, and BP, resulting in decreased myocardial oxygen consumption.111 120 c

• Possibly increases oxygen requirements in patients with heart failure due to increased left ventricular fiber length and end diastolic pressure.111

• Increases airway resistance (at doses >100 mg) in patients with asthma and/or COPD.c

• Produces little or no changes in serum insulin concentrations, time to recovery from insulin-induced hypoglycemia, or free fatty acid response to hypoglycemia.c

• It is used to treat high blood pressure.
• It is used to treat a type of long-term chest pain (stable angina) in some people.
• It is used after a heart attack to lower the chance of death.
• It may be given to you for other reasons. Talk with the doctor.

(a TEN oh lole)

Hypersensitivity to atenolol or any component of the formulation; sinus bradycardia; sinus node dysfunction; heart block greater than first-degree (except in patients with a functioning artificial pacemaker); cardiogenic shock; uncompensated cardiac failure

Canadian labeling: Additional contraindications (not in US labeling): Bradycardia (regardless of origin); cor pulmonale; hypotension; severe peripheral arterial disorders; anesthesia with agents that produce myocardial depression; Pheochromocytoma (in the absence of alpha-blockade); metabolic acidosis

Increased glucose; decreased HDL; may lead to false-positive aldosterone/renin ratio (ARR) (Funder 2016)

Atenolol crosses the placenta and is found in cord blood. Maternal use of atenolol may cause harm to the fetus. Adverse events, such as bradycardia, hypoglycemia and reduced birth weight, have been observed following in utero exposure to atenolol. Adequate facilities for monitoring infants at birth is generally recommended. The maternal pharmacokinetic parameters of atenolol during the second and third trimesters are within the ranges reported in nonpregnant patients (Hebert 2005).

Untreated chronic maternal hypertension and preeclampsia are associated with adverse events in the fetus, infant, and mother (ACOG 2015; Magee 2014). Although beta-blockers may be used when treatment of hypertension in pregnancy is indicated, agents other than atenolol are preferred (ACOG 2013; Magee 2014; Regitz-Zagrosek 2011).

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include extreme weakness or lack of energy, very slow heart rate, shortness of breath, or fainting.

Applies to atenolol: compounding powder, injectable solution, oral tablet

General

The more commonly reported side effects associated with this drug are hypotension, tiredness, and dizziness.[Ref]

Cardiovascular

Bradycardia and hypotension were reported more frequently in patients following a myocardial infarction than among those receiving the drug for treatment of hypertension. In a large study, after a myocardial infarction, patients were more likely to reduce the dosage or discontinue this drug due to bradycardia and hypotension.[Ref]

Common (1% to 10%): Bradycardia, hypotension, cold extremities, heart failure deterioration, heart block precipitation, postural hypotension with or without syncope
Rare (0.01% to 0.1%): Intermittent claudication exacerbation, Raynaud's phenomenon
Frequency not reported: Left ventricular insufficiency
Postmarketing reports: Sick sinus syndrome[Ref]

Other

Very common (10% or more): Tiredness (up to 26%)
Common (1% to 10%): Fatigue
Frequency not reported: Malaise, tinnitus[Ref]

Nervous system

Very common (10% or more): Dizziness (up to 13%)
Common (1% to 10%): Vertigo, lightheadedness, lethargy, drowsiness
Rare (0.01% to 0.1%): Headache, paresthesia
Frequency not reported: Ataxia[Ref]

Psychiatric

Very common (10% or more): Depression (up to 12%)
Common (1% to 10%): Dreaming
Uncommon (0.1% to 1%): Sleep disturbances,
Rare (0.01% to 0.1%): Mood changes, nightmares, confusion, psychoses, hallucinations
Frequency not reported: Vivid dreams, insomnia[Ref]

Respiratory

Common (1% to 10%): Wheezing, dyspnea, pulmonary emboli
Rare (0.01% to 0.1%): Bronchospasm
Frequency not reported: Asthma, nasal congestion[Ref]

Gastrointestinal

Common (1% to 10%): Gastrointestinal disturbances, diarrhea, nausea
Rare (0.01% to 0.1%): Dry mouth
Frequency not reported: Indigestion, constipation[Ref]

Musculoskeletal

Common (1% to 10%): Leg pain[Ref]

Hepatic

Uncommon (0.1% to 1%): Transaminase level elevation
Rare (0.01% to 0.1%): Hepatic toxicity including intrahepatic cholestasis
Postmarketing reports: Elevated bilirubin[Ref]

Renal

Uncommon (0.1% to 1%): Renal failure
Frequency not reported: Increased blood urea, increased serum creatinine[Ref]

Dermatologic

Rare (0.01% to 0.1%): Purpura, alopecia, psoriasiform skin reactions, psoriasis exacerbations, skin rash[Ref]

Genitourinary

Rare (0.01% to 0.1%): Impotence
Postmarketing reports: Peyronie's disease[Ref]

Hematologic

Rare (0.01% to 0.1%): Thrombocytopenia[Ref]

Ocular

Rare (0.01% to 0.1%): Dry eyes, visual disturbances[Ref]

Immunologic

The clinical significance of elevated ANA levels is unknown.[Ref]

Very rare (less than 0.01%): Increase in antinuclear antibodies (ANA)[Ref]

Hypersensitivity

Frequency not reported: Angioedema, urticaria[Ref]

Some side effects of atenolol may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Initial dose: 50 mg orally once a day
-Increase to 100 mg orally once a day after 1 week if optimal response not achieved
Maintenance dose: 50 to 200 mg orally once a day
Maximum dose: 200 mg per day

Comments:
-Some patients may require 200 mg per day to attain optimal effect.

Use: For the long-term management of angina pectoris due to coronary atherosclerosis.

50 mg orally twice a day or 100 mg orally once a day

Comments:
-If IV beta blockers are contraindicated or inappropriate, oral therapy should continue for at least 7 days post-myocardial infarction (MI).
-Treatment with beta blockers post MI should generally continue for 1 to 3 years if there are no contraindications.

Use: For the management of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality.

Use caution

Creatinine clearance 15 to 35 mL/min: Maximum dose is 50 mg per day
Creatinine clearance less than 15 mL/min: Maximum dose is 25 mg per day

Hypertension:
-Initial dose: Consider reducing the starting dose to 25 mg orally once a day
-Assessment regarding efficacy should be made just prior to the next dose to ensure satisfactory blood pressure treatment

• Atenolol is a medication that is used to treat certain heart conditions.
• Atenolol works on specific receptors located in the heart (called beta1 receptors) to slow the heart rate.
• The exact way atenolol works to lower blood pressure is not known but studies have shown it decreases cardiac output, inhibits renin release from the kidneys, and reduces the activity of the sympathetic nervous system.
• Atenolol belongs to the class of drugs known as beta blockers. It is called a selective beta blocker because at low dosages it only works on beta1 receptors and has a low affinity for beta2 receptors located in the airways.

• May be taken with or without food.
• Should always be used as part of a comprehensive cardiovascular risk reduction program which includes diabetes management, smoking cessation, exercise, and other drug therapies. May be used in addition to other blood pressure lowering medicines.
• Seek medical advice immediately if shortness of breath develops.
• Seek medical advice if any new numbness, pain, skin color changes or reduced sensitivity occurs in fingers or toes.
• Sudden discontinuation has been associated with an exacerbation of angina, and sometimes myocardial infarction (heart attack) or ventricular arrhythmias. If you need to discontinue atenolol, your doctor will advise how to do this slowly over at least a week.
• If you have diabetes, atenolol may mask some of the symptoms of hypoglycemia (low blood sugar).

Peak concentrations are reached within two to four hours of an oral dose of atenolol. Heart-rate and blood pressure lowering effects persist for at least 24 hours following a single dose.

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Atenolol crosses the placental barrier and appears in cord blood. Administration of this drug during the second trimester of pregnancy has been associated with small for gestational age births; this may be for related to duration of use. There are no studies for use in the first trimester, however, infant risk cannot be ruled out. Beta-blocker use has been associated with decreased placental perfusion which may lead to intra-uterine deaths, immature and premature deliveries. Neonates exposed to this drug during the third trimester are at risk for adverse reactions due to beta-blockade. There are no adequate and well-controlled studies in pregnant women. US FDA pregnancy category D: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite risks. AU TGA pregnancy category C: Drugs which, owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible. Accompanying texts should be consulted for further details.

Use during pregnancy only if the benefit outweighs risk US FDA pregnancy category: D AU TGA pregnancy category: C Comments: -Apprise women of potential risk to fetus if pregnant or become pregnant while taking this drug. -After birth, monitor infants for the signs of beta blockade, generally expected in first 3 days.

Usual Adult Dose for Hypertension:

Initial dose: 50 mg orally once a day
Maintenance dose: 50 to 100 mg orally once a day
Maximum dose: 100 mg per day

Comments:
-If desired response not achieved after 1 to 2 weeks, increase to 100 mg may be beneficial.
-Doses greater than 100 mg once a day did not result in significant additional antihypertensive effects.

Use: For the treatment of hypertension alone or in combination with other antihypertensive agents.

Usual Adult Dose for Angina Pectoris Prophylaxis:

Initial dose: 50 mg orally once a day
-Increase to 100 mg orally once a day after 1 week if optimal response not achieved
Maintenance dose: 50 to 200 mg orally once a day
Maximum dose: 200 mg per day

Comments:
-Some patients may require 200 mg per day to attain optimal effect.

Use: For the long-term management of angina pectoris due to coronary atherosclerosis.

Usual Adult Dose for Angina Pectoris:

Initial dose: 50 mg orally once a day
-Increase to 100 mg orally once a day after 1 week if optimal response not achieved
Maintenance dose: 50 to 200 mg orally once a day
Maximum dose: 200 mg per day

Comments:
-Some patients may require 200 mg per day to attain optimal effect.

Use: For the long-term management of angina pectoris due to coronary atherosclerosis.

Usual Adult Dose for Myocardial Infarction:

50 mg orally twice a day or 100 mg orally once a day

Comments:
-If IV beta blockers are contraindicated or inappropriate, oral therapy should continue for at least 7 days post-myocardial infarction (MI).
-Treatment with beta blockers post MI should generally continue for 1 to 3 years if there are no contraindications.

Use: For the management of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality.

Usual Geriatric Dose for Hypertension:

Initial dose: Consider reducing the starting dose to 25 mg orally once a day

Tell your doctor about all your current medicines and any you start or stop using, especially:

• digoxin, digitalis;

• indomethacin;

• any other beta-blocker--bisoprolol, carvedilol, labetalol, metoprolol, nebivolol, propranolol, sotalol, timolol, and others; or

• heart or blood pressure medication--amiodarone, clonidine, diltiazem, disopyramide, nicardipine, nifedipine, reserpine, verapamil, and others.

This list is not complete. Other drugs may interact with atenolol, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.