The effect was similar to that obtained when thiazides are used as a single agent .
Thiazides when given as a second-line drug have a dose related effect to lower blood pressure that is similar to when they are added as a first-line drug .
This means that the BP lowering effect of thiazides is additive .
Loop diuretics appear to have a similar blood pressure lowering effect as thiazides at 1 times the recommended starting dose .
Because of the short duration of the trials and lack of reporting of adverse events , this review does not provide a good estimate of the incidence of adverse effects of diuretics given as a second-line drug
BACKGROUND Diuretics are widely prescribed for hypertension not only as a first-line drug but also as a second-line drug .
Therefore , it is essential to determine the effects of diuretics on blood pressure ( BP ) , heart rate and withdrawals due to adverse effects ( WDAEs ) when given as a second-line drug .
The effect of perindopril and hydrochlorothiazide alone and in combination on blood pressure and on the renin-angiotensin system in hypertensive subjects
Summary The pharmacodynamic effects and acceptability of perindopril ( 4 mg daily ) and hydrochlorothiazide ( 25 mg daily ) given alone or in combination for 1 month were investigated in a double-blind ,  placebo controlled , parallel group study . The pharmacokinetics of perindopril and its active metabolite perindoprilat and the time course of angiotensin converting enzyme inhibition were studied for 72 h following the last dose of treatment in the two appropriate groups . Similar decreases in blood pressure were seen 24 h after the last dose of perindopril or hydrochlorothiazide ( 11/7 mm Hg supine ) given alone at these doses . The effect of these drugs given together was additive on diastolic blood pressure and synergistic on systolic blood pressure ( 24.5/12.6 mm Hg supine ) taking into account the placebo response . The significant increase in plasma renin activity produced by perindopril alone was potentiated by concurrent administration of hydrochlorothiazide . The formation of  perindoprilat  was slightly reduced in the group also receiving hydrochlorothiazide and there was a very small reduction in ACE inhibition in this group . Perindopril , whether given alone or in combination with hydrochlorothiazide , was well tolerated and produced no clinical ly significant change in routine haematology or serum biochemistry . The additive or synergistic effects of perindopril and hydrochlorothiazide on blood pressure must be due to their complementary physiological actions and not to a pharmacokinetic interaction
The effect was similar to that obtained when thiazides are used as a single agent .
Thiazides when given as a second-line drug have a dose related effect to lower blood pressure that is similar to when they are added as a first-line drug .
This means that the BP lowering effect of thiazides is additive .
Loop diuretics appear to have a similar blood pressure lowering effect as thiazides at 1 times the recommended starting dose .
Because of the short duration of the trials and lack of reporting of adverse events , this review does not provide a good estimate of the incidence of adverse effects of diuretics given as a second-line drug
BACKGROUND Diuretics are widely prescribed for hypertension not only as a first-line drug but also as a second-line drug .
Therefore , it is essential to determine the effects of diuretics on blood pressure ( BP ) , heart rate and withdrawals due to adverse effects ( WDAEs ) when given as a second-line drug .