What Is Atenolol Used?
Atenolol is a second-generation beta-1-selective adrenergic antagonist used to treat hypertension. The drug is used to treat angina and lower the risk of death after a heart attack. The beta-blocker reduces the workload on the heart and helps to reduce strain on the heart. Atenolol is Food and Drug Administration (FDA) approved for treatment in acute myocardial infarction. It may also be used for the treatment of arrhythmias, migraine prevention, alcohol withdrawal, and prophylaxis against secondary myocardial infarction.
How Does Atenolol Work?
Atenolol affects the response to the nerve impulses such as epinephrine in certain body parts, like the heart and blood vessels. This resulted in lower heartbeats and decreased blood pressure. The beta-blockers effects manifest within one hour of single oral administration, while with an intravenous dose, the effects are evident within five minutes.
Atenolol reaches the peak concentration within two hours of an oral dose. The kidneys predominantly eliminate the hydrophilic beta-receptor, with only 5 percent metabolized by the liver.
What Is the Dosage of Atenolol?
How to Take Atenolol?
Atenolol is available in strengths of 25 milligrams, 50 milligrams, and 100 milligrams. The dosage, drug form, and how often the drug may be taken depends on various factors such as
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Age.
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The condition that is being treated.
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The severity of the condition.
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Other medical conditions.
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Response to the first dose.
The doctor recommends taking the first dose of Atenolol before bedtime, as it can make the person feel dizzy. There should be an eight to ten hours interval between the doses when taking the medication twice daily. Atenolol may be taken with or without food and should be taken at the same time of the day. Atenolol should be swallowed whole with plenty of water. A plastic syringe is provided to measure the liquid form of Atenolol. It is advised that one should not stop taking Atenolol suddenly, as it may worsen the condition.
What Are the Possible Side Effects of Atenolol?
Some commonly observed side effects of Atenolol may include
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New or worsening chest pain.
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Slow, uneven heartbeats.
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Shortness of breath.
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Cold hands and feet.
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Lightheadedness.
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Dizziness.
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Tiredness.
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Leg pain.
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Drowsiness.
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Nausea, vomiting.
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Wheezing.
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Stomach pain.
What Precautions to Be Taken When Taking Atenolol?
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Hypersensitivity - Atenolol should be cautiously administered in patients with a history of allergic reactions or anaphylaxis.
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Pregnancy and Breastfeeding - Atenolol should be given to pregnant women with caution as it may affect fetus growth. Atenolol passes into the breast milk and may cause drowsiness in the baby.
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Congestive Heart Failure - Atenolol reduces myocardial contractility and may worsen or precipitate heart failure, especially during volume overload. Therapy with beta-blockers can be administered cautiously in some congestive heart failure patients who are receiving Digitalis, diuretics, an ACE (angiotensin-converting enzyme) inhibitor, or nitrates.
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Mind Alertness - Atenolol impairs thinking or reactions and should not be taken while driving or handling machinery.
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Alcohol - Avoid drinking alcohol when taking Atenolol, as it may increase drowsiness and dizziness.
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Diabetes - Therapy with beta-blockers should be administered cautiously in patients with diabetes or predisposed to spontaneous hypoglycemia as they affect insulin-induced hypoglycemia and delay the recovery of normal blood sugar levels.
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Children - Beta-blockers should be cautiously administered in small children as they may cause shallow heart rate, lethargy, and coma.
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Asthma - Atenolol is contraindicated in bronchospastic disease as it may worsen the existing conditions.
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Elderly - Beta-blockers should be avoided in older adults because of physiologic changes associated with people over 60 years of age, such as low cardiac output, low glomerular filtration rate, bradycardia, and reduced renal blood flow.
What Are the Interactions of Atenolol with Other Medicines and Supplements?
Drug Interaction:
Some medicines may affect the effectiveness of Atenolol. These medications may include
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Other medicines for high blood pressure like Carvedilol, Metoprolol, Sotalol, and Bisoprolol.
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Amiodarone.
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Digoxin.
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Diltiazem.
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Nifedipine.
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Verapamil.
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Reserpine.
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Clonidine.
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Isocarboxazid.
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Indomethacin.
Interaction with Food:
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Multivitamins with Minerals - Using Atenolol with multivitamins and minerals may decrease the effects of Atenolol. Care should be taken to separate the administration of these drugs by at least two hours.
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Orange Juice - Taking large amounts of orange juice can decrease the effectiveness of Atenolol.
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Alcohol - Alcohol aggravates the effects of Atenolol in lowering blood pressure and may cause headaches, increased heart rate, dizziness, and fainting.
Interaction with Disease:
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Hemodialysis - Patients on hemodialysis should receive a dose of Atenolol following each dialysis as it is moderately removed by conventional hemodialysis.
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Renal Dysfunction - The kidneys eliminate Atenolol. There is significant drug accumulation in patients because of low clearance levels in patients with renal dysfunction.
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Bradyarrhythmias - Atenolol is contraindicated in patients with sinus bradyarrhythmia or heart block.
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Cardiogenic Shock - Atenolol is contraindicated in patients with hypotension as the beta-blockers may further depress the cardiac output and blood pressure.
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Congestive Heart Failure - Beta-adrenergic receptors should not be given to patients with congestive heart failure as it can worsen heart failure.
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Diabetes - Atenolol may mask the symptoms of hypoglycemia, such as tremors, tachycardia, and blood pressure changes in patients with diabetes.
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Ischemic Heart Disease - Cessation of beta-blocker therapy should be done gradually with reduced dosages over some time as there may be an exacerbation of angina, myocardial infarction, and ventricular arrhythmias.
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Glaucoma - Systemic beta-blockers may lower intraocular pressure. Patients with glaucoma may require adjustments in their dosage or discontinue the therapy.
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Hyperthyroidism - Abrupt withdrawal of beta-adrenergic blockers can exacerbate thyrotoxicosis or precipitate a thyroid storm. Close monitoring is recommended during and after therapy withdrawal.
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Myasthenia Gravis - Beta-blockers may potentiate muscle weakness and symptoms such as diplopia, ptosis, and generalized weakness.
Conclusion:
Atenolol lowers blood pressure, so it is essential to check the blood pressure periodically. It is advised not to stop taking Atenolol suddenly as it may increase the risk of a heart attack. Eating a healthy diet with lots of fruits, vegetables, low-fat meat, and dairy products, and avoiding packaged or processed foods provide added benefits.