Tenormin 50 mg Tablets

Brand Name

The medication is marketed under the trade name Tenormin, a widely recognized label in cardiovascular pharmacotherapy. This branding distinguishes it as a trusted option for managing specific heart and blood pressure conditions across various patient populations.

International Non-Proprietary Name (INN)

Tenormin is identified globally by its international non-proprietary name, atenolol. This term specifies the active pharmacological substance responsible for its therapeutic effects, ensuring consistency in its designation across medical practices worldwide.

Form of Release

This drug is primarily available as film-coated tablets for oral administration, offered in strengths of 25 mg, 50 mg, and 100 mg to accommodate diverse dosing needs. Additionally, an injectable solution at 0.5 mg/mL in 10 mL vials is provided for acute care settings, allowing flexibility in both outpatient and hospital-based treatments.

Composition

The core active ingredient in Tenormin is atenolol, a selective beta-1 adrenergic receptor blocker that drives its cardiovascular benefits. Tablets include inactive components such as microcrystalline cellulose, sodium starch glycolate, magnesium stearate, and a coating with hypromellose, titanium dioxide, and polyethylene glycol for protection and ease of use. The injectable formulation contains sodium chloride and water for injection, with sodium hydroxide or hydrochloric acid added to adjust pH, ensuring stability during intravenous delivery.

Pharmacologic Properties

Pharmacodynamics

Tenormin exerts its effects by selectively blocking beta-1 receptors in the heart, reducing the influence of catecholamines like adrenaline on cardiac tissue. This action decreases heart rate and contractility, lowering cardiac output and oxygen demand, which helps stabilize blood pressure and relieve strain on the heart. Unlike non-selective agents, its specificity minimizes bronchial or peripheral vascular interference, making it particularly suited for cardiac-focused therapy. These properties contribute to its efficacy in regulating rhythm and pressure dynamics.

Pharmacokinetics

Following oral administration, atenolol in Tenormin is absorbed from the gastrointestinal tract, with bioavailability averaging 50% due to partial hepatic metabolism avoidance. Peak plasma concentrations occur within 2 to 4 hours for tablets, or rapidly with injection. It distributes moderately, with a volume of 0.7 L/kg, and crosses the blood-brain barrier minimally due to low lipophilicity, binding to plasma proteins at less than 5%. Excretion is predominantly renal, with 85-90% eliminated unchanged in urine, and a half-life of 6 to 7 hours in healthy individuals, extending in renal impairment.

Indications for Use

Diseases and Conditions

Tenormin is prescribed for hypertension management, effectively lowering elevated blood pressure to reduce cardiovascular risk. It is also indicated for angina pectoris, particularly effort-induced, by decreasing myocardial oxygen requirements during physical activity. Additionally, it serves as an adjunct in post-myocardial infarction care, improving survival by controlling heart rate and preventing arrhythmias in the early recovery phase, highlighting its versatility in cardiac health.

Contraindications

Conditions Prohibiting Use

Tenormin must not be used in patients with known hypersensitivity to atenolol or any formulation excipient, as reactions could range from skin eruptions to severe allergic events. It is unsuitable for those with sinus bradycardia, heart rates below 50 beats per minute, or second- to third-degree atrioventricular block without pacing, due to risks of exacerbating conduction delays. Cardiogenic shock and uncontrolled heart failure also preclude its use, as reduced cardiac stimulation could worsen these states. Individuals with severe peripheral artery disease or untreated pheochromocytoma should avoid it to prevent circulatory or hypertensive complications.

Method of Administration and Dosage

Administration Guidelines

Tenormin tablets are taken orally, with or without food, as absorption remains unaffected by meals. They should be swallowed whole with water, ideally at the same time daily for consistency. The injectable form is administered intravenously by healthcare professionals, typically as a slow bolus or infusion, diluted in saline or dextrose if needed, with careful monitoring to avoid rapid pressure drops. Abrupt cessation should be avoided to prevent rebound effects.

Dosage for Adults and Children

For adults with hypertension, Tenormin typically starts at 50 mg once daily, adjustable to 100 mg if needed after 1-2 weeks based on response. In angina, 50-100 mg daily is common, titrated to symptom control. Post-myocardial infarction dosing begins with 5-10 mg IV over 10 minutes, followed by 50 mg orally twice daily for 1-2 days, then 100 mg daily. Pediatric use, though rare, may involve 0.5-1 mg/kg daily orally, capped at 2 mg/kg or 100 mg, adjusted cautiously under specialist guidance due to limited data.

Dose Adjustment in Specific Conditions

Renal impairment necessitates dose reduction; in creatinine clearance below 35 mL/min, 50 mg daily is standard, dropping to 25 mg or every other day below 15 mL/min, reflecting reliance on kidney excretion. Hepatic dysfunction rarely requires adjustment, as metabolism is minimal, though monitoring is prudent in severe cases. Elderly patients often start at 25-50 mg daily, with increases based on tolerance, accounting for age-related renal decline and sensitivity to beta-blockade.

Side Effects

Potential Adverse Reactions

Tenormin may provoke various unintended effects, commonly including fatigue, cold hands or feet, and mild dizziness due to its heart rate-lowering action. Gastrointestinal disturbances like nausea or diarrhea can occur, as can sleep disturbances or vivid dreams in some users. Respiratory symptoms, such as wheezing, are rare but possible in predisposed individuals. Bradycardia or hypotension may emerge, particularly at higher doses, while skin reactions like rashes are infrequent. Most effects subside with time or dose modification, though persistent issues warrant medical attention.

Overdose

Symptoms of Overdose

Excessive Tenormin intake can lead to profound bradycardia, with heart rates dropping dangerously low, accompanied by hypotension causing faintness or collapse. Respiratory depression or bronchospasm may develop, particularly in susceptible patients, alongside lethargy or confusion from reduced cerebral perfusion. Severe cases might involve heart block or cardiac arrest, signaling urgent need for intervention to restore vital functions.

First Aid Measures

In an overdose, discontinue Tenormin and position the patient supine, seeking immediate medical help. Atropine (0.5-2 mg IV) may counter bradycardia, while glucagon (5-10 mg IV) supports cardiac output if needed. Intravenous fluids or vasopressors like dopamine address hypotension, with bronchodilators relieving airway constriction. Cardiac monitoring ensures timely escalation, such as pacing, if conduction worsens, continuing until stability returns.

Drug Interactions

Effects on Other Medications

Tenormin can enhance the effects of other antihypertensives, such as calcium channel blockers or ACE inhibitors, requiring dose coordination to avoid excessive pressure drops. It may intensify bradycardia when combined with non-dihydropyridine calcium blockers like verapamil or diltiazem, necessitating rhythm checks. Concurrent use with insulin or oral hypoglycemics might mask hypoglycemia signs, demanding glucose monitoring. It has minimal impact on drug metabolism, as it is not a significant enzyme substrate.

Compatibility with Alcohol and Food

Alcohol consumption with Tenormin may amplify drowsiness or pressure-lowering effects, suggesting moderation. Food does not significantly alter absorption, though consistent timing relative to meals aids steady blood levels. No specific dietary restrictions apply, but avoiding sudden caffeine shifts helps maintain predictable cardiac response.

Special Precautions

Use During Pregnancy and Breastfeeding

Tenormin crosses the placenta, with potential for fetal growth restriction or bradycardia, so it is used only when benefits outweigh risks, typically under close supervision. Atenolol appears in breast milk, possibly causing infant hypotension or bradycardia; breastfeeding mothers should monitor infants or consider alternatives, consulting providers for tailored decisions.

Impact on Driving and Operating Machinery

Tenormin may induce dizziness or fatigue, especially during initiation or dose changes, potentially affecting driving or machinery use. Patients should assess their tolerance before such tasks, refraining if symptoms persist, to ensure safety until adjusted to the medication’s impact.

Considerations for Elderly and Pediatric Populations

Elderly individuals may require lower Tenormin doses, starting at 25 mg, due to reduced renal function and heightened sensitivity, with gradual increases if tolerated. Pediatric use is uncommon, reserved for specific hypertensive or arrhythmic cases, with dosing at 0.5-1 mg/kg daily under expert care, reflecting limited safety data. Both groups benefit from individualized adjustments to optimize outcomes while minimizing risks.