Betaloc-XR100 mg

Betaloc-XR is a cardioselective beta-1 adrenergic receptor blocker. Its FDA-approved and well-established indications include:

• Hypertension: Used alone or in combination with other antihypertensive agents to lower blood pressure.
• Angina pectoris: Long-term management to reduce the frequency and severity of angina attacks.
• Myocardial infarction (heart attack): To reduce cardiovascular mortality in hemodynamically stable patients, given early after the event.

Guideline-supported and commonly used off-label indications include:

• Rate control in atrial fibrillation and atrial flutter.
• Management of certain supraventricular tachyarrhythmias.
• Symptomatic treatment of hyperthyroidism-related tachycardia (as an adjunct, not a substitute for definitive treatment).
• Migraine prophylaxis (off-label use).

Note: Betaloc-XR is the immediate-release salt form, typically dosed multiple times daily, and is a distinct product from extended-release metoprolol succinate, which is dosed once daily and is separately approved for chronic heart failure.

Each tablet contains Metoprolol Tartrate USP as the active ingredient, commonly available in strengths of 25 mg, 50 mg, and 100 mg. An injectable formulation (5 mg/5 mL) is also available for hospital use. Excipients vary by manufacturer.

Betaloc-XR is a cardioselective beta-1 adrenergic receptor blocking agent belonging to the beta-blocker class of cardiovascular drugs. It is the immediate-release salt of metoprolol and is used in the management of hypertension, angina pectoris, and after myocardial infarction. At usual clinical doses, Betaloc-XR preferentially blocks beta-1 receptors located mainly in cardiac tissue, reducing heart rate, myocardial contractility, and blood pressure, with comparatively less effect on beta-2 receptors found in bronchial and vascular smooth muscle.

Betaloc-XR belongs to the therapeutic class of selective beta-1 adrenergic receptor blockers (cardioselective beta-blockers), a subgroup within the broader beta-adrenergic blocking agent class used in cardiovascular medicine.

Metoprolol Tartrate selectively blocks beta-1 adrenergic receptors, which predominate in cardiac tissue, at doses lower than those required to block beta-2 receptors. This selectivity is relative and diminishes at higher doses. By blocking beta-1 receptors, Metoprolol Tartrate reduces the effects of circulating catecholamines on the heart, resulting in:

• Decreased heart rate (negative chronotropic effect)
• Decreased myocardial contractility (negative inotropic effect)
• Decreased cardiac output and blood pressure
• Reduced renin release from the kidneys

Metoprolol Tartrate is well absorbed after oral administration, undergoes significant first-pass hepatic metabolism via the CYP2D6 enzyme pathway, and has an elimination half-life of approximately 3 to 7 hours, which is why it is generally dosed two to three times daily for consistent effect.

Betaloc-XR tablets are for oral use. Take with or immediately following food to help ensure consistent absorption. Swallow tablets whole with water; tablets that are scored may be split if directed by the physician. Do not crush or chew unless instructed. Take doses at the same times each day.

Betaloc-XR has clinically significant interactions with the following:

• Verapamil and diltiazem (non-dihydropyridine calcium channel blockers): Additive risk of severe bradycardia, AV block, and hypotension due to combined negative chronotropic and inotropic effects; avoid or use with extreme caution and monitoring.
• Digoxin: Additive bradycardic effect; increased risk of significant bradycardia, requiring monitoring of heart rate.
• Clonidine: Concurrent use requires caution; if both are being discontinued, metoprolol should be withdrawn first, several days before clonidine, to avoid rebound hypertension.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine, propafenone): Can significantly increase metoprolol plasma concentrations, increasing the risk of bradycardia and hypotension; dose adjustment may be needed.
• Catecholamine-depleting drugs (e.g., reserpine, MAO inhibitors): May cause additive hypotension and bradycardia, including syncope.
• Insulin and oral antidiabetic agents: Betaloc-XR may mask key symptoms of hypoglycemia such as tachycardia and tremor; blood glucose monitoring should be intensified.
• NSAIDs: May reduce the antihypertensive effect of Betaloc-XR.

Common side effects of Betaloc-XR include:

• Fatigue and tiredness
• Dizziness or lightheadedness
• Bradycardia (slow heart rate)
• Hypotension (low blood pressure)
• Cold hands and feet
• Diarrhea, nausea
• Shortness of breath
• Depression, sleep disturbances

Less common but serious side effects requiring prompt medical attention include severe bradycardia, worsening heart failure (swelling, weight gain, breathlessness), bronchospasm (especially in patients with reactive airway disease), and heart block. See Precautions and Warnings for abrupt-discontinuation risks.

Pregnancy: Betaloc-XR crosses the placenta. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, and only under close physician supervision. Neonates born to mothers treated with Betaloc-XR near delivery should be monitored for signs of beta-blockade such as bradycardia, hypotension, hypoglycemia, and respiratory depression.

Lactation: Betaloc-XR is excreted into breast milk in small amounts. Breastfeeding infants should be monitored for signs of beta-blockade (e.g., unusual sleepiness, poor feeding, slow heart rate). Use during breastfeeding only after consulting a physician, weighing benefits against potential risk.

Do not stop abruptly: Abrupt discontinuation of Betaloc-XR can cause rebound hypertension, exacerbation of angina, tachycardia, ventricular arrhythmias, or myocardial infarction, particularly in patients with underlying coronary artery disease. Discontinue gradually over 1-2 weeks under medical supervision, whenever possible.

Heart failure: Use with caution in patients with compensated heart failure; may worsen cardiac function in some patients, especially at initiation or during dose increases.

Bronchospastic disease (asthma/COPD): Although Betaloc-XR is relatively cardioselective, this selectivity is not absolute, especially at higher doses, and beta-2 blockade can precipitate bronchospasm. Use with caution and the lowest effective dose, with a bronchodilator available if needed.

Diabetes mellitus: Betaloc-XR may mask tachycardia and tremor associated with hypoglycemia. Use with caution and monitor blood glucose closely in diabetic patients.

Peripheral vascular disease: May aggravate symptoms of arterial insufficiency.

Thyrotoxicosis: May mask signs of hyperthyroidism (e.g., tachycardia); abrupt withdrawal may precipitate thyroid storm.

Anesthesia and major surgery: Continued beta-blockade reduces the risk of arrhythmias during anesthesia and surgery; withdrawal should not be routine before surgery unless directed by the treating physician.

Conduction abnormalities: Use with caution in first-degree AV block.

Overdose of Betaloc-XR may cause severe bradycardia, hypotension, cardiogenic shock, cardiac arrest, bronchospasm, and loss of consciousness. Overdose is a medical emergency.

If overdose is suspected, seek immediate medical attention or contact emergency services/poison control right away. Do not attempt to manage a suspected overdose at home. Treatment will be provided by medical professionals in a hospital setting based on the severity of symptoms.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Pediatric use: Safety and efficacy of Betaloc-XR in pediatric patients have not been well established for most indications; use in children should be under specialist supervision only if considered necessary.

Elderly: No overall differences in effectiveness have been observed, but elderly patients may be more sensitive to blood-pressure-lowering and heart-rate-lowering effects; start at the lower end of the dosing range and titrate cautiously.

Renal impairment: No specific dose adjustment generally required, but monitor clinically.

Hepatic impairment: Use with caution and lower starting doses, as Betaloc-XR is extensively metabolized by the liver.

Duration of treatment with Betaloc-XR depends on the indication. For hypertension and angina, treatment is typically long-term/chronic, continuing as long as clinically indicated and tolerated. For post-myocardial infarction use, treatment is generally continued for at least 3 months, and often longer, as determined by the treating cardiologist. Treatment duration and any changes should always be guided by a physician; do not discontinue without medical advice due to abrupt-withdrawal risks (see Precautions and Warnings).

Beta-adrenergic blocking agent; specifically a cardioselective (beta-1 selective) blocker.

Metoprolol Tartrate selectively and competitively blocks beta-1 adrenergic receptors, which are predominantly located in cardiac tissue. This reduces the stimulatory effects of catecholamines (epinephrine and norepinephrine) on the heart, leading to decreased heart rate, decreased myocardial contractility, decreased cardiac output, and reduced renin release, ultimately lowering blood pressure and myocardial oxygen demand.

Category C

Safety and efficacy of Betaloc-XR have not been well established in pediatric patients for most indications. Use in children and adolescents should only occur under close specialist supervision when a physician determines the potential benefit outweighs the risk, with careful individualized dosing.