Norvasc (Amlodipine)

• Norvasc (amlodipine) is used to manage cardiovascular conditions that involve elevated vascular resistance and myocardial oxygen demand.
• Hypertension: reduces systolic and diastolic blood pressure, helping to prevent complications such as stroke, myocardial infarction, and renal disease.
• Chronic stable angina: improves coronary blood flow by vasodilation, decreasing frequency of angina attacks and need for short‑acting nitrates.
• Coronary artery disease: lowers myocardial oxygen demand and improves exercise tolerance, contributing to overall cardiovascular risk reduction.

• Amlodipine selectively inhibits calcium influx through L‑type voltage‑gated calcium channels located on vascular smooth‑muscle cells and cardiac myocytes. By blocking these channels, it prevents calcium‑dependent contraction, causing arterial vasodilation and a modest reduction in cardiac contractility. The resulting decrease in peripheral vascular resistance lowers blood pressure, while enhanced coronary artery diameter improves myocardial oxygen delivery. The effect persists for 24 hours, allowing once‑daily dosing.

Amlodipine may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Peripheral edema: swelling of the ankles or feet due to fluid accumulation.
• Headache: mild to moderate tension‑type headache.
• Flushing: transient warmth and redness of the skin.
• Dizziness or light‑headedness: especially after standing quickly.
• Fatigue: feeling unusually tired or weak.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure leading to fainting.
• Cardiac arrhythmias: irregular heart rhythms that may require medical attention.
• Hepatotoxicity: abnormal liver function tests indicating possible liver injury.

When prescribing amlodipine, clinicians should consider several safety considerations to minimize risk.

• Blood pressure monitoring: check baseline and periodic readings to assess response.
• Concomitant heart failure: use cautiously as vasodilation may exacerbate symptoms.
• Liver impairment: dose may need adjustment in moderate to severe hepatic dysfunction.
• Drug interactions: review patient’s medication list for agents that affect calcium channel blockers.
• Pregnancy and lactation: avoid unless benefits outweigh potential risks, as safety data are limited.
• Store at ambient temperature: keep below 25 °C in original packaging, protect from moisture.

Amlodipine can interact with other medicines, altering its effectiveness or safety profile.

Major Interactions (Avoid)

• Simultaneous use with strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase amlodipine plasma levels and risk of hypotension.
• Co‑administration with other potent vasodilators (e.g., nitroglycerin, hydralazine): can cause excessive blood pressure lowering.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, phenytoin): may reduce amlodipine concentrations, diminishing efficacy.
• Beta‑blockers: combined effect on heart rate and blood pressure requires monitoring.
• Diuretics: additive antihypertensive effect may lead to orthostatic hypotension.
• Statins (especially simvastatin): increased risk of statin‑related myopathy; monitor muscle symptoms.