Prolonged antihypertensive effect of amlodipine: a prospective double-blind randomized study

Blood Press. 1999;8(1):43-8. doi: 10.1080/080370599438383.


Amlodipine is a calcium antagonist with a long elimination half-life (35 to 50 h) allowing a once daily dosing in the treatment of hypertension. This randomized, double-blind study was performed to assess the residual antihypertensive effect of amlodipine 5 mg O.D. 3 days after discontinuing therapy in previously well-controlled mild to moderate hypertensive patients. Blood pressure (BP) was evaluated by conventional (OBP) and by ambulatory blood pressure monitoring (ABPM). Amlodipine 5 mg OD administered during a 6-week period, significantly reduced both OBP and ABPM mean values (p < 0.05), whereas no change in heart rate was observed. At the end of the active treatment period, adequately controlled patients were randomized either to amlodipine 5 mg OD (group A) or amlodipine for 12 days followed by a 3-day period on placebo. After this double-blind treatment phase, group P exhibited no significant increase in BP (assessed by OBP or ABPM) when compared to group A. In conclusion, the duration of action of amlodipine extends largely beyond the 24-h span, and when patients omit their treatment for 3 days BP does not significantly increase.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Amlodipine / pharmacology*
  • Amlodipine / therapeutic use
  • Antihypertensive Agents / pharmacology*
  • Antihypertensive Agents / therapeutic use
  • Blood Pressure / drug effects
  • Blood Pressure Determination
  • Blood Pressure Monitoring, Ambulatory
  • Calcium Channel Blockers / pharmacology*
  • Calcium Channel Blockers / therapeutic use
  • Double-Blind Method
  • Female
  • Heart Rate / drug effects
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Time Factors


  • Antihypertensive Agents
  • Calcium Channel Blockers
  • Amlodipine