title: The response to the first dose of an angiotensin converting enzyme inhibitor in uncomplicated hypertension--a placebo controlled study utilising ambulatory blood pressure recording.
abstract: 1. The importance of total dose to the initial hypotensive response with an angiotensin converting enzyme inhibitor (quinapril) was assessed using a suggested 'maintenance' dose (20 mg) or matched placebo in a randomised double-blind study in patients with uncomplicated hypertension. 2. Thirty-two patients were recruited who were not on therapy or had not received diuretic therapy in their existing drug treatment in the preceding 4 weeks. Secondary causes of hypertension had previously been excluded and sustained clinic blood pressures of SBP greater than 160 mmHg and/or DBP greater than 90 mmHg were taken as indications for a trial of adjuvant or monotherapy with an ACE inhibitor. 3. After uneventful supervised therapy with quinapril in an open pilot study (n = 5) 27 patients entered a double-blind, randomised, crossover study of quinapril or placebo using ambulatory monitoring to assess BP response. 4. All patients remained asymptomatic and both therapy and monitoring were well tolerated. A smooth onset of antihypertensive effect was noted with an overall 24 h placebo corrected fall in systolic BP of 9.9 mmHg (7.2-12.6 95% CI) and diastolic BP of 6.4 mmHg (4.2-8.8) with no significant effect on heart rate. Individual placebo corrected maximal responses during the first 8 h following quinapril showed a wide range for both systolic (+1.56 to 44.0 mmHg) and diastolic (+2.3 to -35.6 mmHg) pressure. Larger falls tended to be associated with higher baseline pretreatment pressures but in no case did absolute systolic pressure fall below 100 mmHg during the first 8 h following administration of placebo or quinapril.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: University Department of Medicine and Therapeutics, Stobhill General Hospital, Glasgow.
authors.forename: R J
authors.initials: RJ
authors.lastname: MacFadyen
authors.forename: A D
authors.initials: AD
authors.lastname: Bainbridge
authors.forename: K R
authors.initials: KR
authors.lastname: Lees
authors.forename: J L
authors.initials: JL
authors.lastname: Reid
mesh_terms: D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007546:Isoquinolines / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010919:Placebos; D000077583:Quinapril; D044005:Tetrahydroisoquinolines
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007546:Isoquinolines; D010919:Placebos; D044005:Tetrahydroisoquinolines; D000077583:Quinapril