1619
document
Effects of amlodipine and enalapril on platelet function in patients with mild to moderate hypertension . OBJECTIVE The aim of this study was to compare the effect of amlodipine and enalapril on platelet aggregation , and platelet production of malondialdehyde in patients with mild to moderate arterial hypertension . PATIENTS AND METHODS A parallel , double-blind , placebo-controlled study was carried out in 24 patients ( 2 groups of 12 patients each ) . Initially all patients received placebo for four weeks ; then amlodipine , 5 mg daily or enalapril 20 mg daily taken once a day at 7 am . Dosage was doubled after 4 weeks when diastolic blood pressure was > 90 mmHg in sitting position , the treatment was continued for 12 weeks . At the end of placebo and active phases a platelet aggregation test , using adenosine diphosphate , collagen and adrenaline , and a platelet malondialdehyde production test , either in basal conditions ( MDA-basal ) and after the stimulation of arachidonic acid pathway by adding ethylmaleimide ( MDA-activated ) were carried out . RESULTS Blood pressure was reduced by both agents , enalapril and amlodipine . Enalapril controlled 58.3 % of hypertensive patients with an average dosage of 31.7 mg/daily . Amlodipine controlled 75 % of patients with a dosage of 7.1 mg/daily . Platelet aggregation was reduced by amlodipine in 15.9 % for ADP ( 10 microM ) ; 17.4 % for collagen ( 2 microg/ml ) and 19.9 % for adrenaline ( 2 microM ) ( p < 0.025 ) . Meanwhile enalapril slightly increased platelet aggregation by 6.7 % , 1.3 % and 5.6 % for the three agents , respectively ( p > 0.05 , ns ) . Malondialdehyde was reduced by amlodipine in 45.33 % ( p < 0.05 ) for MDA-basal ; 3.76 % ( p > 0.05 ) for MDA-activated ; and the ratio MDA-basal : MDA-activated in 36.79 % ( p < 0.005 ) . Meanwhile enalapril increased MDA-basal in 2.89 % ; MDA-activated in 3.58 % and reduced the ratio MDA-basal : MDA-activated , in 10.34 % ( p > 0.05 ) . CONCLUSION Both agents , enalapril and amlodipine , reduced blood pressure , but only amlodipine reduced platelet aggregation and platelet production of malondialdehyde , indicating its action on the arachidonic acid metabolic pathway .
1620
Intervention_Pharmacological
amlodipine
1621
Intervention_Pharmacological
enalapril
1622
Intervention_Pharmacological
amlodipine and enalapril
1623
Intervention_Control
placebo-controlled
1624
Intervention_Control
placebo
1625
Intervention_Pharmacological
amlodipine
1626
Intervention_Pharmacological
or enalapril
1627
Intervention_Pharmacological
enalapril
1628
Intervention_Pharmacological
amlodipine
1629
Intervention_Pharmacological
Enalapril
1630
Intervention_Pharmacological
Amlodipine
1631
Intervention_Pharmacological
amlodipine
1632
Intervention_Pharmacological
enalapril
1633
Intervention_Pharmacological
amlodipine
1634
Intervention_Pharmacological
enalapril
1635
Intervention_Pharmacological
enalapril
1636
Intervention_Pharmacological
amlodipine
1637
Intervention_Pharmacological
amlodipine
1638
Outcome_Physical
platelet function
1639
Outcome_Physical
platelet aggregation
1640
Outcome_Physical
platelet production of malondialdehyde
1641
Outcome_Physical
diastolic blood pressure
1642
Outcome_Physical
Blood pressure
1643
Outcome_Physical
Platelet aggregation
1644
Outcome_Physical
platelet aggregation
1645
Outcome_Physical
Malondialdehyde
1646
Outcome_Physical
MDA-basal
1647
Outcome_Physical
MDA-activated
1648
Outcome_Physical
MDA-basal
1649
Outcome_Physical
MDA-activated
1650
Outcome_Physical
ratio MDA-basal : MDA-activated
1651
Outcome_Physical
blood pressure
1652
Outcome_Physical
platelet aggregation
1653
Outcome_Physical
platelet production of malondialdehyde
1654
Participant_Condition
hypertension
1655
Participant_Condition
arterial hypertension
1656
Participant_Sample-size
24
1657
Participant_Sample-size
12
1658
Participant_Condition
hypertensive