Amlodipine (Norvasc)   Felodipine (Plendil) 
  • Calcium channel blockers are effective in treating hypertension because they reduce peripheral resistance.
  • Amlodipine (Norvasc) and Felodipine (Plendil) have relatively little effects on reducing myocardial contractility compared to verapamil (Isoptin, Calan) or diltiazem (Cardiazem).
  • Arteriolar vascular tone depends on free intracellular Ca2+ concentration.
    • Calcium channel blockers reduce transmembrane movement of Ca2+
    • reduce the amount reaching intracellular sites
    • and therefore reduce vascular smooth muscle tone.
  • All calcium channel blocks appear similarly effective for management of mild to moderate hypertension.
  • For low-renin hypertensive patients (elderly and African-American groups), Ca2+ channel blockers appear good choices for monotherapy (single drug) control.

 

Adverse Effects
  •  SA nodal inhibition may lead to bradycardia or SA nodal arrest.
  • This effect is more prominent if beta adrenergic antagonists are concurrently administered.
  • GI reflux.
  •  Negative inotropic are augmented if beta-adrenergic receptor antagonists are concurrently administered.
  •  Calcium channel blockers should not be administered if the patient has SA or AV nodal abnormalities or in patients with significant congestive heart failure.