Norvasc (amlodipine besylate) is a leading prescription calcium channel blocker medication specifically designed for the management of hypertension (high blood pressure) and chronic stable angina. It functions by relaxing and widening blood vessels, allowing blood to flow more easily, which reduces the heart’s workload and improves oxygen supply. Trusted by healthcare professionals globally, Norvasc offers a well-established safety profile and consistent 24-hour efficacy from a single daily dose, making it a cornerstone therapy in cardiovascular treatment plans aimed at reducing the risk of heart attack and stroke.

Features

• Active Ingredient: Amlodipine besylate.
• Drug Class: Dihydropyridine calcium channel blocker (CCB).
• Available Strengths: 2.5 mg, 5 mg, and 10 mg oral tablets.
• Dosing Regimen: Once-daily administration, with or without food.
• Onset of Action: Gradual; full therapeutic effect may take 1-2 weeks.
• Duration of Action: Provides consistent 24-hour blood pressure control.
• Bioavailability: Approximately 64-90% following oral administration.
• Half-life: Long plasma elimination half-life of 30-50 hours.
• Metabolism: Extensively metabolized in the liver via CYP3A4 enzyme.
• Excretion: Primarily renal (60%) and fecal (20-25%).

Benefits

• Provides smooth, sustained 24-hour blood pressure control, minimizing fluctuations.
• Reduces the frequency of angina attacks and need for nitrate therapy in patients with coronary artery disease.
• Lowers the overall workload on the heart, helping to prevent long-term cardiovascular damage.
• Demonstrates a favorable side effect profile compared to other antihypertensive classes, with a low incidence of metabolic disturbances.
• Offers convenient once-daily dosing, improving patient adherence to treatment regimens.
• Can be used as monotherapy or effectively combined with other antihypertensive agents like ACE inhibitors or diuretics.

Common use

Norvasc is primarily indicated for the first-line treatment of hypertension in adults and pediatric patients 6 years and older. It is used to lower elevated blood pressure, reducing the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. Additionally, it is approved for the management of chronic stable angina and vasospastic (Prinzmetal’s or variant) angina when used alone or in combination with other antianginal drugs. In clinical practice, it is often selected for patients who require consistent blood pressure control without significant heart rate effects, and it is particularly valuable in elderly patients and those with isolated systolic hypertension.

Dosage and direction

The recommended initial adult dosage for hypertension or angina is 5 mg taken orally once daily. The dosage may be increased to a maximum dose of 10 mg once daily based on individual patient response and tolerability. For pediatric patients (6-17 years), the recommended starting dose is 2.5 mg once daily, not to exceed 5 mg daily. Small, fragile, elderly, or hepatically impaired patients may be started on 2.5 mg once daily. Administration may occur with or without food, preferably at the same time each day to maintain steady plasma concentrations. Dose titration should generally occur over 7-14 days. The tablets should be swallowed whole with a glass of water and not crushed or chewed.

Precautions

Patients should undergo regular blood pressure monitoring, especially during initial therapy and following dose adjustments. Use with caution in patients with severe hepatic impairment, as amlodipine clearance is reduced, necessitating lower starting doses and careful titration. Although Norvasc generally does not affect cardiac conduction, caution is advised in patients with severe aortic stenosis, heart failure (especially NYHA Class III-IV), or following acute myocardial infarction. Peripheral edema is a known dose-dependent side effect; patients should be advised to report significant swelling, particularly of the ankles or feet. Abrupt discontinuation is not associated with rebound hypertension, but therapy should not be stopped without medical supervision. Patients should avoid grapefruit juice, which may increase plasma concentrations.

Contraindications

Norvasc is contraindicated in patients with known hypersensitivity to amlodipine or any component of the formulation. It must not be administered to individuals who have demonstrated allergic reactions to other dihydropyridine calcium channel blockers. There are no absolute contraindications related to severe heart failure in the product labeling, but extreme caution is required in these populations. Use is contraindicated in situations where hypotension would pose a serious risk to the patient.

Possible side effect

The most common side effect is peripheral edema (ankle and foot swelling), which is dose-related and occurs in up to 10% of patients at higher doses. Other frequently reported adverse reactions include headache (7.3%), fatigue (4.5%), nausea (2.9%), flushing (2.6%), and palpitations (2.1%). Dizziness and somnolence have been reported in 1-3% of patients. Less common but clinically significant side effects may include hypotension, gingival hyperplasia, and pruritus. Rare cases of severe adverse effects include myocardial infarction, arrhythmias, and hepatitis, though causal relationships are not firmly established. Most side effects are mild to moderate and often diminish with continued therapy.

Drug interaction

Norvasc is primarily metabolized by CYP3A4 enzymes, creating potential interactions with inhibitors and inducers of this pathway. Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir) may increase amlodipine plasma concentrations, potentially requiring dose reduction. Concomitant use with simvastatin should not exceed 20 mg daily of simvastatin. Additive hypotensive effects may occur when used with other antihypertensives, nitrates, or phosphodiesterase-5 inhibitors. Use with beta-blockers may increase risk of hypotension and heart failure exacerbation in susceptible patients. Cyclosporine may increase amlodipine concentrations, while amlodipine may increase systemic exposure to cyclosporine.

Missed dose

If a dose is missed, it should be taken as soon as remembered on the same day. If it is nearly time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed. Patients should not take a double dose to make up for a missed one. Maintaining consistent daily administration is important for optimal blood pressure control, but occasional missed doses are unlikely to cause significant clinical consequences due to the drug’s long half-life.

Overdose

Overdose may lead to pronounced peripheral vasodilation with marked hypotension and possibly reflex tachycardia. Cases of significant overdose could progress to shock with fatal outcomes. Symptoms may include dizziness, lightheadedness, and syncope. Management involves active cardiovascular support with elevation of extremities and judicious administration of fluids. Vasoconstrictors such as norepinephrine or phenylephrine may be considered if necessary. As amlodipine is highly protein-bound, hemodialysis is not likely to be effective. Gastric lavage may be beneficial if performed soon after ingestion. Continuous monitoring of vital signs and cardiac function is essential.

Storage

Store Norvasc tablets at controlled room temperature, between 20°C to 25°C (68°F to 77°F), with excursions permitted between 15°C to 30°C (59°F to 86°F). Keep in the original container, tightly closed, and protect from light and moisture. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging. Properly discard any unused or expired medication through medication take-back programs or according to local guidelines, not by flushing down toilets or pouring into drains.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Norvasc is a prescription medication that should only be used under the supervision of a qualified healthcare professional. Individual patient responses and requirements may vary. Always consult with a physician or pharmacist for personalized medical advice, diagnosis, or treatment recommendations. Do not initiate, adjust, or discontinue medication without professional guidance. Full prescribing information should be reviewed before administration.

Reviews

Clinical studies and post-marketing surveillance demonstrate that Norvasc is generally well-tarded by patients, with many reporting significant improvements in blood pressure control and reduced angina symptoms. Healthcare providers frequently note its predictable pharmacokinetics and favorable interaction profile as advantages in long-term management. Some patients report dissatisfaction with peripheral edema at higher doses, though this often improves with dose reduction or combination therapy. Overall, it maintains a strong reputation in the medical community for efficacy and reliability in cardiovascular risk reduction.