Norvasc (amlodipine besylate) is a leading prescription medication in the calcium channel blocker class, specifically developed for the management of hypertension and chronic stable angina. Its primary mechanism of action involves the selective inhibition of calcium ion influx across cardiac and vascular smooth muscle cell membranes, resulting in peripheral arterial vasodilation and reduced systemic vascular resistance. This comprehensive profile details the pharmacological characteristics, clinical applications, and essential safety information for healthcare professionals considering this therapeutic agent for appropriate patient populations.

Features

• Active ingredient: Amlodipine besylate
• Therapeutic class: Dihydropyridine calcium channel blocker
• Available strengths: 2.5 mg, 5 mg, and 10 mg oral tablets
• Long half-life: Approximately 30-50 hours permitting once-daily dosing
• Gradual onset of action with prolonged duration of effect
• Hepatic metabolism with inactive urinary excretion
• No significant effect on cardiac conduction or contractility

Benefits

• Provides sustained 24-hour blood pressure control with single daily dosing
• Reduces peripheral vascular resistance without compromising cardiac output
• Demonstrates efficacy in both hypertension and angina management
• Minimal impact on heart rate and metabolic parameters
• Suitable for use in diverse patient populations including elderly patients
• Compatible with many other antihypertensive regimens

Common use

Norvasc is indicated for the first-line treatment of hypertension, either as monotherapy or in combination with other antihypertensive agents. It is also approved for the management of chronic stable angina and vasospastic (Prinzmetal’s) angina when beta-blockers are contraindicated or ineffective. The medication may be particularly beneficial for patients with isolated systolic hypertension, African-American patients, and those with concomitant asthma or diabetes where other antihypertensive classes may be less desirable.

Dosage and direction

The recommended initial dosage for hypertension is 5 mg once daily, which may be increased to a maximum of 10 mg daily based on therapeutic response. For angina, the starting dose is 5-10 mg once daily, with most patients requiring 10 mg for adequate symptom control. Dosage adjustments should be made gradually over 7-14 days. The medication may be administered with or without food. Elderly patients or those with hepatic impairment may require lower starting doses (2.5 mg daily) with careful titration. Regular blood pressure monitoring is essential during dosage adjustments.

Precautions

Patients should be monitored for peripheral edema, which is dose-dependent and more common in women. Blood pressure should be measured regularly during therapy. Use with caution in patients with severe aortic stenosis due to reduced afterload reduction. Hepatic impairment may increase systemic exposure to amlodipine, requiring dosage adjustment. Abrupt discontinuation may cause rebound hypertension or angina exacerbation. Patients should avoid alcohol consumption as it may potentiate vasodilation and orthostatic effects.

Contraindications

Norvasc is contraindicated in patients with known hypersensitivity to amlodipine or any component of the formulation. It should not be used in patients with severe hypotension (systolic pressure <90 mmHg) or cardiogenic shock. The medication is contraindicated in patients with unstable angina not controlled by standard therapy. Concomitant use with strong CYP3A4 inhibitors in patients with hepatic impairment requires careful risk-benefit assessment.

Possible side effects

Common adverse reactions include peripheral edema (dose-related), headache, fatigue, nausea, abdominal pain, and dizziness. Less frequent effects include palpitations, flushing, somnolence, and gingival hyperplasia. Serious but rare side effects include symptomatic hypotension, worsening angina or myocardial infarction (particularly at initiation), and hypersensitivity reactions. Peripheral edema typically presents as ankle or foot swelling and may respond to dosage reduction or diuretic therapy.

Drug interaction

Moderate interactions occur with simvastatin (limit to 20 mg daily), cyclosporine (increased exposure), and CYP3A4 inhibitors including ketoconazole, itraconazole, and ritonavir. Additive hypotensive effects may occur with other antihypertensives, nitrates, phosphodiesterase-5 inhibitors, and alcohol. Calcium supplements may reduce effectiveness. Use with beta-blockers requires monitoring for excessive bradycardia or heart failure exacerbation in susceptible patients.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. Patients should not double the dose to make up for a missed administration. Consistent daily dosing at approximately the same time each day maintains optimal therapeutic levels. Healthcare providers should educate patients about the importance of adherence to prescribed dosing schedules.

Overdose

Symptoms of overdose include profound hypotension and reflex tachycardia. Bradycardia may occur with concomitant beta-blocker use. Management involves cardiovascular monitoring with elevation of lower extremities and administration of intravenous fluids. Vasopressors such as dopamine or norepinephrine may be required for refractory hypotension. Calcium gluconate administration (10% solution) may help reverse calcium channel blockade. Hemodialysis is not effective due to high protein binding.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in the original container. Protect from light and moisture. Keep tightly closed and out of reach of children. Do not use if tablets show evidence of discoloration or physical deterioration. Proper disposal of unused medication should follow local regulations for pharmaceutical waste.

Disclaimer

This information is intended for healthcare professionals and should not replace individualized medical advice. Treatment decisions must be based on the clinician’s assessment of the patient’s specific clinical circumstances. Prescribers should consult full prescribing information and current clinical guidelines before initiating therapy. Patients should be thoroughly educated about proper use, potential side effects, and monitoring requirements.

Reviews

Clinical trials demonstrate Norvasc produces significant reductions in both systolic and diastolic blood pressure with once-daily dosing. The ASCOT-BPLA trial showed amlodipine-based therapy reduced cardiovascular events compared to atenolol-based regimen. Long-term studies confirm maintained efficacy over 52 weeks of treatment with good tolerability profile. Real-world evidence supports effectiveness in diverse populations, though peripheral edema remains a treatment-limiting factor in approximately 5-10% of patients at higher doses.