Norvasc

Norvasc is the brand name for amlodipine besilate, a calcium channel blocker in the dihydropyridine class. It is used to treat high blood pressure and angina. Amlodipine acts as a long-acting vasodilator that relaxes arterial smooth muscle, reducing peripheral vascular resistance and lowering blood pressure.

The main medical uses are hypertension and chronic stable angina. It is also approved for vasospastic angina (Prinzmetal angina). Amlodipine is typically prescribed as a once-daily oral medication and may be used alone or with other antihypertensive agents.

Mechanism of action: Amlodipine inhibits L-type calcium channels in arterial smooth muscle, producing vasodilation and decreased afterload. The drug has a limited direct effect on heart rate or cardiac conduction at usual doses, and its cardiovascular effects are mainly due to arterial dilation rather than venous pooling.

Administration and dosage: Norvasc is taken by mouth, with or without food, usually once daily. For hypertension, the starting dose is commonly 5 mg once daily, increased to 10 mg if needed and tolerated, with a maximum of 10 mg daily. For angina, dosing follows similar principles, adjusted for individual response and tolerance. Dose adjustments may be necessary for elderly patients or those with hepatic impairment.

Side effects and interactions: Common adverse effects include edema (especially of the ankles), dizziness, flushing, palpitations, fatigue, and gingival overgrowth. Nausea can occur. Amlodipine is a substrate of CYP3A4, so inhibitors or inducers can alter levels; grapefruit juice may increase exposure. When combined with certain statins, dose guidance for simvastatin may apply, and additive blood pressure lowering is possible with other antihypertensives.

Warnings: Pregnancy category C; use during pregnancy and breastfeeding should be discussed with a clinician. Caution is advised in heart failure with reduced ejection fraction, significant aortic stenosis, or severe hypotension.