Betaloc-XR 50 mg

Indications
Betaloc-XR is used in the management of several cardiovascular conditions, including hypertension and angina pectoris. It is effective in controlling cardiac arrhythmias, particularly supraventricular tachyarrhythmias. Betaloc-XR is also used as an adjunct therapy in hyperthyroidism management. Early administration of Betaloc-XR in cases of acute myocardial infarction helps reduce infarct size and lower the incidence of ventricular fibrillation. Additionally, it may provide pain relief, reducing the need for opioid analgesics. Clinical studies have demonstrated that Betaloc-XR can reduce mortality rates when administered to patients who have suffered an acute myocardial infarction.
Always follow the advice of a registered healthcare provider.

Pharmacology
Betaloc-XR contains Metoprolol, which is a selective beta1-adrenergic blocker. Metoprolol works by inhibiting the effects of catecholamines—hormones released during physical or emotional stress—on the heart. This results in a reduction in heart rate, cardiac output, contractility, and blood pressure, which would otherwise increase in response to elevated catecholamines. Metoprolol has minimal impact on insulin secretion and carbohydrate metabolism compared to non-selective beta-blockers, and it has a lesser effect on the cardiovascular response to hypoglycemia.

Dosage & Administration

Film-Coated Tablets

• Hypertension: The recommended total daily dose is between 100-400 mg, taken either as a single dose or in divided doses. The initial dose is 100 mg per day (equivalent to two Metoprolol-50 tablets). The dosage can be increased by 100 mg at weekly intervals. If adequate control is not achieved with a single daily dose, a twice-daily dosing regimen may be considered. Combining Metoprolol with other antihypertensive medications, such as diuretics, can also be effective.
• Angina: The typical dose for angina pectoris is 50 mg (one Metoprolol-50 tablet) to 100 mg (two Metoprolol-50 tablets) taken two or three times daily.
• Cardiac Arrhythmias: For the treatment of cardiac arrhythmias, the usual dose is 50 mg (one Metoprolol-50 tablet) taken twice or three times daily. The dose may be increased to a maximum of 300 mg per day, divided into multiple doses. Following intravenous treatment for acute arrhythmia, oral Metoprolol should be started 4-6 hours later, not exceeding an initial dose of 50 mg three times daily.
• Hyperthyroidism: A dose of 50 mg (one Metoprolol-50 tablet) should be taken four times a day. The dose can be reduced once the thyroid function returns to normal.
• Myocardial Infarction: Therapy should begin 15 minutes after the last intravenous dose, with 50 mg every 6 hours for 48 hours. If the full intravenous dose is not tolerated, the oral dose should be reduced to half. The maintenance dose is usually 200 mg per day, divided into multiple doses.
• Elderly: No special dosage adjustments are required for elderly patients with normal health. However, significant liver dysfunction may require dose adjustments.

Extended-Release Tablets

• Hypertension: The initial dose is between 25 mg and 100 mg per day, which can be taken as a single dose, either alone or with a diuretic.
• Angina Pectoris: The initial dose of Metoprolol Succinate extended-release tablets is 100 mg daily, adjusted according to the individual patient’s response.
• Heart Failure: For patients with NYHA class II heart failure, the recommended starting dose is 25 mg daily for two weeks. For more severe cases, a starting dose of 12.5 mg daily is advised. Dosage can be increased weekly (or at longer intervals) to achieve the desired effect. If treatment is discontinued, the dosage should be tapered gradually over 1-2 weeks.

Intravenous Injection

• Arrhythmias: Up to 5 mg may be administered via intravenous injection at a rate of 1-2 mg per minute, with a maximum total dose of 10-15 mg.
• Surgical Procedures: To control arrhythmias during surgery, slow intravenous injections of 2-4 mg may be given at induction, with additional 2 mg doses up to a maximum of 10 mg.
• Myocardial Infarction: Within 12 hours of a myocardial infarction, intravenous doses of 5 mg can be given every 2 minutes until a total of 15 mg is reached. Following this, oral administration should begin with 50 mg every 6 hours for 48 hours, with maintenance at 200 mg daily.

Always follow the guidance of a registered healthcare provider.

Interactions
Metoprolol may have an additive effect when taken with catecholamine-depleting drugs such as Reserpine or MAO inhibitors. Drugs that inhibit CYP2D6, including quinidine, fluoxetine, paroxetine, and propafenone, can increase the plasma concentration of Betaloc-XR. This could decrease the cardioselectivity of the drug. When used alongside digitalis glycosides, there may be an increased risk of bradycardia. Beta-blockers can also worsen rebound hypertension upon the withdrawal of clonidine.

Contraindications
Metoprolol should not be used in patients with:

• AV block
• Uncontrolled heart failure
• Severe bradycardia
• Sick-sinus syndrome
• Cardiogenic shock
• Severe peripheral arterial disease
• Hypersensitivity to Metoprolol or other beta-blockers
  Additionally, Metoprolol is contraindicated if myocardial infarction is complicated by significant bradycardia, first-degree heart block, systolic hypotension (below 100 mmHg), or severe heart failure.

Side Effects
Potential side effects include:

• Fatigue, dizziness, depression, diarrhea, skin rashes, or itching
• Shortness of breath, slow heart rate, mental confusion
• Headaches, sleep disturbances, including nightmares or insomnia
• Gastrointestinal issues such as nausea, dry mouth, gastric pain, constipation, and flatulence
• Vision problems, musculoskeletal pain, blurred vision, decreased libido, and tinnitus
  Additionally, the severity of AV block may intensify.

Pregnancy & Lactation
Metoprolol is classified as a Pregnancy Category C drug. There are insufficient controlled studies in pregnant women, so the medication should only be used during pregnancy if absolutely necessary. Metoprolol is excreted in breast milk in small amounts, so caution is advised when used by breastfeeding mothers.

Precautions & Warnings

• Bronchospastic Conditions: Though Metoprolol is relatively selective for beta1 receptors, it should be used with caution in patients with bronchospastic diseases who cannot tolerate other antihypertensive treatments.
• Major Surgery: The withdrawal of beta-blockers before major surgery is a subject of debate, as it may impair the heart’s response to stress during general anesthesia, increasing surgical risks.
• Diabetes and Hypoglycemia: Beta-blockers can mask the tachycardia associated with hypoglycemia. However, symptoms such as dizziness and sweating may not be significantly affected.
• Peripheral Vascular Disease: Beta-blockers can aggravate arterial insufficiency in patients with peripheral vascular disease.
• Calcium Channel Blockers: Caution should be taken when Metoprolol is used alongside calcium channel blockers due to potential significant effects on heart function.

Use in Special Populations

• Hepatic Impairment: Caution is required in patients with impaired liver function.
• Pediatric Use: Safety and efficacy have not been established in children under 6 years of age. In pediatric patients aged 6-16, no significant difference in adverse effects compared to adults has been observed.
• Geriatric Use: There are no significant differences in efficacy or adverse event rates between elderly and younger patients.

Overdose Effects
Overdosing on Metoprolol may cause severe hypotension, sinus bradycardia, heart block, heart failure, cardiogenic shock, cardiac arrest, bronchospasm, loss of consciousness, coma, nausea, vomiting, cyanosis, hypoglycemia, and, in some cases, hyperkalemia. Initial symptoms usually occur within 20 minutes to 2 hours after ingestion. Treatment involves close monitoring of cardiovascular, respiratory, and renal function, as well as blood glucose and electrolyte levels. If overdose is suspected, immediate actions such as inducing vomiting, gastric lavage, or administering activated charcoal should be performed. Symptomatic treatments may include the use of sympathomimetic drugs, atropine, inotropes, or temporary pacing.

Storage Conditions
Store Betaloc-XR in a cool, dry place away from light to maintain its effectiveness.