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 .
Antihypertensive effectiveness of low-dose lisinopril-hydrochlorothiazide combination. A large multicenter study. Lisinopril-Hydrochlorothiazide Group.
OBJECTIVE To test the antihypertensive and metabolic effects of lisinopril , 10 mg/d ( L ) ; hydrochlorothiazide , 12.5 and 25 mg/d ( H12.5 and H25 ) ; and its combination with lisinopril ( L/H12.5 and L/H25 ) against placebo in patients with mild to moderate ( stage I and stage II ) hypertension . DESIGN Multicenter , double-blind , placebo-controlled outpatient study of 12 weeks ' duration . PATIENTS After 4 weeks of single-blind placebo treatment , 505 patients whose sitting diastolic blood pressure was 100 to 114 mm Hg were r and omized into the study --467 patients completed it  ( placebo , 71 ; L , 80 ; H12.5 , 79 ; H25 , 77 ; L/H12.5 , 79 ; and L/H25 , 81 ) . The patients were seen in the clinic every 2 weeks , where measurements of their sitting and upright blood pressure and heart rate were taken 24 + /- 2 hours after drug administration . Complete blood cell counts with differential cell counts , blood chemistry studies , urinalyses , and electrocardiograms were done at baseline and during the study . Roentgenograms were done once at baseline . RESULTS Compared with placebo , all drug regimens decreased sitting and upright blood pressure ( P < .001 ) and had no effect on sitting and upright heart rate . The greatest effect was obtained with the combinations of L/H12.5 and L/H25 . There was no difference between L/H12.5 and L/H25 or between H12.5 and H25 . There were no serious clinical side effects except cough , which was slightly higher with L , L/H12.5 , and L/H25 . The only metabolic side effects were in serum potassium level , which was lower with H25 ( P < .01 ) , and serum glucose level , which was higher with H25 and L/H25 ( P < .01 ) . CONCLUSIONS The data suggest that ( 1 ) monotherapy of hypertension with L , H12.5 , H25 , L/H12.5 , and L/H25 was effective and well tolerated ; ( 2 ) the best results were achieved with L/H12.5 and L/H25 ; ( 3 ) lower doses of hydrochlorothiazide either alone or in combination with lisinopril were equipotent with higher doses and were free of metabolic side effects
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 .