Inderal 10 mg Tablets

Brand Name

This medication is marketed under the trade name Inderal, a label widely recognized among healthcare professionals for its role in managing various cardiovascular and related conditions.

International Nonproprietary Name (INN)

The active ingredient is identified globally as propranolol, ensuring its uniform recognition across medical practices worldwide.

Form of Release

The drug is available in multiple forms, including immediate-release tablets, extended-release capsules, and an injectable solution, offering flexibility for oral or intravenous administration based on patient needs. These formulations come in different strengths to accommodate diverse therapeutic requirements and maintain stability under standard storage conditions.

Composition

Propranolol hydrochloride serves as the primary active substance, designed to influence specific physiological pathways. In tablets and capsules, inactive ingredients such as lactose monohydrate, microcrystalline cellulose, magnesium stearate, and gelatin provide structural support and aid in dissolution or release timing. The injectable form includes sodium chloride and citric acid to ensure compatibility with intravenous delivery. Some oral formulations may feature a coating of hypromellose or colorants for identification. Each component is carefully selected to enhance the therapeutic action of propranolol without altering its effectiveness.

Pharmacologic Properties

Pharmacodynamics

This medication functions as a non-selective beta-adrenergic receptor blocker, targeting both beta-1 and beta-2 receptors to exert its effects. By inhibiting the action of catecholamines like adrenaline and noradrenaline, it reduces heart rate, myocardial contractility, and oxygen demand, making it valuable for controlling cardiovascular workload. It also decreases renin release from the kidneys, contributing to blood pressure reduction. Beyond cardiac effects, its ability to block beta-2 receptors in smooth muscles can influence bronchial tone and peripheral vasculature. Effects typically begin within 30 minutes of oral administration, with peak activity occurring within one to four hours, providing sustained benefits with regular use. This broad receptor blockade underlies its versatility across multiple conditions.

Pharmacokinetics

Following oral administration, the drug absorbs rapidly from the gastrointestinal tract, though bioavailability varies widely (20% to 40%) due to extensive first-pass metabolism in the liver. Food enhances absorption, increasing plasma levels. Peak concentrations occur within one to four hours for immediate-release forms, while extended-release capsules provide a more gradual profile. Propranolol binds approximately 90% to plasma proteins and distributes extensively, crossing the blood-brain barrier and reaching tissues like the heart and lungs. It undergoes hepatic metabolism via cytochrome P450 enzymes, primarily CYP2D6, producing active metabolites like 4-hydroxypropranolol. Elimination occurs mainly through urine as metabolites, with a half-life of three to six hours for immediate-release forms and eight to ten hours for extended-release. Hepatic impairment significantly alters clearance, while renal dysfunction has less impact.

Indications for Use

This medication is prescribed for a variety of conditions requiring cardiovascular or autonomic regulation. It is a cornerstone treatment for hypertension, reducing blood pressure by decreasing cardiac output and renin activity. It also manages angina pectoris by lowering myocardial oxygen demand, improving exercise tolerance in affected patients. In arrhythmias, such as supraventricular tachycardia, it stabilizes heart rhythm by slowing conduction through the atrioventricular node. Post-myocardial infarction, it reduces mortality risk by mitigating cardiac stress. Beyond cardiology, it treats essential tremor by dampening sympathetic overactivity and prevents migraine headaches by stabilizing vascular tone. Its anxiolytic effects make it useful for performance anxiety, while in hyperthyroidism, it controls symptoms like tachycardia until underlying causes are addressed.

Contraindications

Certain conditions preclude the use of this drug to avoid serious health risks. Hypersensitivity to propranolol or any formulation component prohibits its administration, as reactions could range from skin irritation to anaphylaxis. Severe bradycardia, second- or third-degree heart block, or sick sinus syndrome without a pacemaker contraindicates it, given its heart rate-lowering effects. It is avoided in cardiogenic shock or decompensated heart failure, where beta-blockade could worsen cardiac output. Asthma or severe chronic obstructive pulmonary disease with bronchospasm risks its use due to potential airway constriction. Uncontrolled diabetes or hypoglycemia-prone states also limit its application, as it may mask warning signs of low blood sugar. Significant peripheral artery disease requires caution to prevent exacerbation of ischemia.

Method of Administration and Dosage

How to Take

Tablets or capsules are taken orally, preferably with food to enhance absorption, while the injectable form is administered intravenously by healthcare professionals. Swallowing oral forms whole with water ensures proper delivery to the stomach. Consistent timing each day maintains stable blood levels, with extended-release capsules typically taken once daily and immediate-release tablets divided into multiple doses.

Dosage for Adults and Children

For adults with hypertension, treatment often starts at 40 mg twice daily for immediate-release tablets, increasing to 120 mg to 240 mg daily based on response, or 80 mg once daily for extended-release, up to 320 mg. In angina, 80 mg to 320 mg daily is common, adjusted for symptom relief. Arrhythmias may require 10 mg to 30 mg three to four times daily, while post-myocardial infarction dosing begins at 40 mg three times daily, titrated to 180 mg to 240 mg daily. For tremor or migraine prevention, 40 mg twice daily may rise to 120 mg to 160 mg daily. Children with arrhythmias or hypertension receive 0.5 mg to 1 mg per kilogram daily, divided into two to four doses, adjusted under specialist care. Monitoring ensures efficacy and safety across indications.

Dose Adjustment in Specific Conditions

Renal impairment generally requires no adjustment, as excretion is primarily hepatic, though monitoring for fluid status is prudent. Hepatic dysfunction necessitates lower doses, starting at 20 mg to 40 mg daily, due to slowed metabolism and risk of accumulation. Elderly patients or those with reduced cardiac reserve may begin with 20 mg twice daily to minimize bradycardia or hypotension. Gradual titration and regular assessments tailor dosing to individual physiological capacity, especially in compromised states.

Side Effects

This medication may provoke a variety of unintended reactions, though their frequency varies. Fatigue, dizziness, or drowsiness are common, often linked to reduced cardiac output or central nervous system effects, particularly early in therapy. Bradycardia or cold extremities might occur due to slowed heart rate and peripheral vasoconstriction. Gastrointestinal issues like nausea, diarrhea, or abdominal discomfort affect some users but typically subside with time. Respiratory symptoms, such as wheezing or shortness of breath, can arise in susceptible individuals with airway sensitivity. Rarely, severe effects like depression, hallucinations, or significant hypotension emerge, requiring prompt medical attention. Patient feedback and periodic evaluations help manage these responses effectively.

Overdose

Symptoms of Overdose

Excessive intake can lead to severe bradycardia, resulting in weakness, fainting, or cardiac arrest from excessive beta-blockade. Hypotension may cause dizziness, confusion, or shock due to reduced cardiac output and vascular tone. Bronchospasm or respiratory distress might develop in those with airway predisposition, complicating breathing. Seizures or coma could occur in extreme cases, reflecting central nervous system depression. Symptoms typically appear within hours and escalate without intervention, highlighting the drug’s potent systemic effects.

First Aid Measures

In an overdose situation, discontinue administration immediately and seek urgent medical assistance. If ingestion is recent, gastric lavage or activated charcoal may reduce absorption, performed under professional supervision. Intravenous atropine addresses bradycardia, while fluids or vasopressors like dopamine support blood pressure. Bronchodilators like albuterol relieve airway constriction, and glucagon may counter beta-blockade effects on the heart. Continuous cardiac monitoring stabilizes the patient until recovery, focusing on restoring normal rhythm and circulation.

Drug Interactions

Effects on Other Medications

This drug influences the performance of various medications when used together. It can enhance the effects of other antihypertensives, risking excessive blood pressure reduction, so careful dose calibration is needed. Concurrent use with calcium channel blockers like verapamil increases bradycardia or heart block risks, requiring close monitoring. It may reduce the efficacy of bronchodilators like salbutamol by opposing beta-2 stimulation. Antidiabetic agents’ hypoglycemic effects might be masked, necessitating glucose checks. Adjustments and oversight minimize these interactions effectively.

Compatibility with Alcohol and Food

Alcohol consumption may intensify drowsiness or hypotension, particularly due to additive central nervous system depression, so moderation is advised. Food enhances oral absorption, improving bioavailability, though no strict dietary restrictions apply beyond avoiding excessive stimulants like caffeine, which could counteract its calming effects. Balanced intake supports optimal outcomes.

Special Precautions

Use During Pregnancy and Breastfeeding

Inderal is not recommended during pregnancy unless benefits outweigh risks, as it may cause fetal bradycardia or growth restriction, based on limited human data. It passes into breast milk, potentially affecting infant heart rate, so nursing mothers should consult their physician, possibly opting for alternatives to reduce exposure.

Impact on Driving and Machinery Operation

Dizziness or fatigue, especially at initiation or dose changes, may impair driving or machinery operation. Patients should assess their tolerance before engaging in such activities, ensuring safety for themselves and others.

Considerations for Elderly and Pediatric Populations

Elderly individuals may require lower starting doses due to heightened sensitivity to bradycardia or hypotension, with regular checks for tolerance. In children, its use is tailored to specific conditions like arrhythmias, with weight-based dosing adjusted cautiously under specialist guidance to avoid developmental impact. Personalized care optimizes safety across these groups.