title: Reduction of morning blood pressure surge after treatment with nifedipine GITS at bedtime, but not upon awakening, in essential hypertension.
abstract: OBJECTIVE
  The extent of morning blood pressure (BP) surge upon wakening has been associated with increased incidence of stroke and cardiovascular mortality. This trial investigated the antihypertensive efficacy and effects on the morning BP surge of awakening versus bedtime administration of nifedipine in essential hypertension.
  
  
  METHODS
  We studied 238 previously untreated hypertensive patients (108 men and 130 women), 53.3+/-11.4 years of age, randomly assigned to receive nifedipine (30 mg/day) as a monotherapy either upon awakening or at bedtime. BP was measured for 48 h before and after 8 weeks of treatment.
  
  
  RESULTS
  The BP reduction after the treatment was significantly greater with bedtime dosing (P<0.001). The proportion of patients with controlled ambulatory BP thus increased from 28 to 43% (P = 0.019) with bedtime treatment. The sleep time relative BP decline was unchanged after morning treatment, but increased toward a more dipping pattern after bedtime dosing (P = 0.026 between groups). The morning BP surge was unchanged after the administration of nifedipine upon awakening (1.4/1.2 mmHg reduction in systolic/diastolic BP surge, P>0.270), but significantly reduced after bedtime dosing (6.2/4.4 mmHg reduction, P<0.001).
  
  
  CONCLUSIONS
  Nifedipine efficiently reduces BP for the entire 24 h and to a significantly larger extent after bedtime administration. The significant added efficacy on reducing night-time BP, the decrease in the prevalence of a nondipper BP pattern, and the significant decrease in morning BP surge (all relevant markers of cardiovascular morbidity and mortality) of bedtime as compared with morning administration, consistently indicate that nifedipine should preferably be administered at bedtime in patients with essential hypertension.
authors: Bioengineering and Chronobiology Laboratories, University of Vigo, Vigo, Spain. rhermida@uvigo.es
authors: Ramón C
authors: RC
authors: Hermida
authors: Diana E
authors: DE
authors: Ayala
authors: Artemio
authors: A
authors: Mojón
authors: Ignacio
authors: I
authors: Alonso
authors: José R
authors: JR
authors: Fernández
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D018660:Blood Pressure Monitoring, Ambulatory; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000627:therapeutic use*; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
chemical_list: D000959:Antihypertensive Agents; D009543:Nifedipine