When the blood pressure lowering effect of beta-blockers from this review was compared to that of thiazide diuretics from our previous review ( Chen 2009 ) , second-line beta-blockers reduce systolic BP to the same extent as second-line thiazide diuretics , but reduce diastolic BP to a greater degree .
The different effect on diastolic BP means that beta-blockers have little or no effect on pulse pressure whereas thiazides cause a significant dose-related decrease in pulse pressure .
This difference in the pattern of BP lowering with beta-blockers as compared to thiazides might be the explanation for the fact that beta-blockers appear to be less effective at reducing adverse cardiovascular outcomes than thiazide diuretics , particularly in older individuals
BACKGROUND Beta-blockers are one of the more commonly prescribed classes of anti-hypertensive drugs , both as first-line and second-line .
OBJECTIVES To quantify the effect on systolic blood pressure ( SBP ) , diastolic blood pressure ( DBP ) , heart rate and withdrawals due to adverse effects of beta-blocker therapy when given as a second-line drug in adult patients with primary hypertension .
Low-dose atenolol-chlorthalidone combination for treatment of mild hypertension.
In a r and omized , double-blind , within-patient study , 28 out- patients with mild to moderate hypertension were given , at the end of a 3-week placebo wash-out period , four different antihypertensive treatments for 3 weeks each . the treatments were 50 mg atenolol , 100 mg atenolol , 12.5 mg chlorthalidone and a fixed combination of 50 mg atenolol and 12.5 mg chlorthalidone . All treatments were given once daily . Visits were scheduled for the last day of each treatment period , 24 - 26 hours after the last dose , and there was an intermediary wash-out period between each pair of active treatments . Supine systolic/diastolic blood pressure was 165/102 on placebo , 153/93 mmHg on 50 mg atenolol , 155/91 mmHg on 100 mg atenolol , 148/93 mmHg on 12.5 mg chlorthalidone and 144/89 mmHg on the combination . All the changes in pressure were significant ( p less than 0.01 ) versus placebo .  Supine systolic blood pressure was lower on the combination than on 100 mg atenolol alone ( p less than 0.05 ) and upright systolic pressure was lower on the combination than on 100 mg atenolol ( p less than 0.05 ) or 50 mg atenolol ( p less than 0.05 ) alone . The heart rate was lowered by atenolol alone or combined with chlorthalidone but did not fall below 56 bpm in any patient . Serum potassium levels were lower on 12.5 mg chlorthalidone than on placebo ( 3.88 mEq/l vs 4.09 mEq/l -- p less than 0.05 ) but the difference was trivial ; on the combination of atenolol-chlorthalidone there was no significant difference versus placebo ( 3.97 mEq/l vs 4.09 mEq/l -- NS ) . ( ABSTRACT TRUNCATED AT 250 WORDS
When the blood pressure lowering effect of beta-blockers from this review was compared to that of thiazide diuretics from our previous review ( Chen 2009 ) , second-line beta-blockers reduce systolic BP to the same extent as second-line thiazide diuretics , but reduce diastolic BP to a greater degree .
The different effect on diastolic BP means that beta-blockers have little or no effect on pulse pressure whereas thiazides cause a significant dose-related decrease in pulse pressure .
This difference in the pattern of BP lowering with beta-blockers as compared to thiazides might be the explanation for the fact that beta-blockers appear to be less effective at reducing adverse cardiovascular outcomes than thiazide diuretics , particularly in older individuals
BACKGROUND Beta-blockers are one of the more commonly prescribed classes of anti-hypertensive drugs , both as first-line and second-line .
OBJECTIVES To quantify the effect on systolic blood pressure ( SBP ) , diastolic blood pressure ( DBP ) , heart rate and withdrawals due to adverse effects of beta-blocker therapy when given as a second-line drug in adult patients with primary hypertension .