Which has a stronger effect on blood pressure, Losartan (angiotensin II receptor antagonist) or Atenolol (beta blocker)?

Losartan Has a Stronger Effect on Blood Pressure Than Atenolol in Patients with Left Ventricular Hypertrophy

Losartan demonstrates superior cardiovascular protection and blood pressure reduction compared to atenolol, particularly in patients with left ventricular hypertrophy, despite similar overall antihypertensive efficacy in general hypertensive populations. 1

Comparative Antihypertensive Efficacy

• In most hypertensive patients, losartan and atenolol produce comparable blood pressure reductions:

  • Short-term studies (up to 12 weeks) show similar blood pressure reductions with both medications 2
  • In direct comparisons, losartan 50-100 mg daily produces similar systolic blood pressure reductions to atenolol 50-100 mg daily 3
  • Diastolic blood pressure reductions may be slightly greater with atenolol (10.1 mmHg vs 8.3 mmHg with losartan) 3

• However, important differences exist in specific populations:

  • In patients with isolated systolic hypertension, losartan's efficacy is similar to atenolol 2
  • In women with essential hypertension, losartan significantly reduces systolic blood pressure from 155 mmHg to 139 mmHg and diastolic blood pressure from 100 mmHg to 87 mmHg, even in those with low plasma renin activity 4

Superior Effects of Losartan in Left Ventricular Hypertrophy

• The Losartan Intervention For Endpoint reduction in hypertension study (LIFE) demonstrated that losartan is more effective than atenolol in patients with left ventricular hypertrophy: 5

  • Losartan significantly reduced left ventricular mass index (LVMI) by 6.56 g/m² from baseline (p<0.001) 6
  • Atenolol did not significantly reduce LVMI (-3.71 g/m², p=NS) 6
  • The estimated treatment difference between losartan and atenolol was -2.5 g/m² in favor of losartan 6

• This superior effect on LVH regression occurs despite similar blood pressure reductions, suggesting mechanisms beyond blood pressure control: 6

  • Losartan reduces circulating concentrations of cardiac natriuretic peptides
  • Losartan is more effective in decreasing myocardial fibrosis compared to atenolol

Cardiovascular Protection Beyond Blood Pressure Control

• Losartan offers additional cardiovascular protection beyond blood pressure reduction:

  • In the LIFE study, losartan was more effective in reducing the primary composite cardiovascular endpoint than atenolol 5
  • The beneficial effect of losartan was even more apparent in diabetic patients, with a statistically significant difference in all-cause mortality 5
  • Losartan reduces plasma aldosterone concentration and serum uric acid levels, which may contribute to its cardiovascular benefits 4

• Losartan's superior cardiovascular protection may be due to:

  • More complete blockade of the actions of angiotensin II than ACE inhibitors 2
  • Effects on cardiac structure and function beyond blood pressure reduction 6
  • Reduction in myocardial fibrosis 5

Tolerability and Safety Considerations

• Losartan demonstrates better tolerability compared to atenolol:
  • In patients with isolated systolic hypertension, losartan had a lower adverse event rate (10.4%) compared to atenolol (23%) 2
  • Losartan treatment is associated with significantly fewer drug-related clinical adverse events compared with atenolol (10% vs 22%, p=0.028) 6
  • Atenolol reduces pulse rate by approximately 10 beats/min, while losartan does not affect heart rate 3

Clinical Implications and Recommendations

• For patients with hypertension and left ventricular hypertrophy, losartan is the preferred choice over atenolol due to:

  • Superior regression of left ventricular hypertrophy 6
  • Better cardiovascular outcomes 5
  • Improved tolerability profile 6

• For general hypertensive patients without specific compelling indications:

  • The European Society of Cardiology recommends angiotensin receptor blockers like losartan over beta-blockers like atenolol as first-line therapy 1
  • Beta-blockers like atenolol should be reserved for patients with specific compelling indications such as angina, post-myocardial infarction, heart failure with reduced ejection fraction, or heart rate control 1

• When initiating losartan therapy:

  • Start with 50 mg once daily
  • Consider increasing to 100 mg once daily if blood pressure response is insufficient
  • Consider adding hydrochlorothiazide if monotherapy is inadequate 1

In conclusion, while both medications have similar overall antihypertensive efficacy in general hypertensive populations, losartan demonstrates superior cardiovascular protection, better regression of left ventricular hypertrophy, and improved tolerability compared to atenolol, making it the preferred choice for most hypertensive patients, particularly those with left ventricular hypertrophy.