Jan 6, 2014

Atenolol versus Metoprolol in treatment of hypertension

Recent guideline from ISH says for treatment of hypertension any drug that the patient can take and afford is OK. But In last few years the atenolol has been projected as villain, so most doctors have started moving away from prescribing atenolol and some patient also want their atenolol to be changed to other drugs.
In recent both JNC 8 and ISH guidelines, beta blockers are no more preferred drugs for treating hypertension, they have been pushed far down in algorithm.

Both Metoprolol and atenolol are beta one selective blocker.  Now most pharmaceutical companies have come with combination of amlodipine and Metoprolol before these companies use to promote amlodipine with atenolol. 

ISH/ASH guidlines for hypertension

Lovers of Metoprolol over the atenolol claimed, lipophilic Metoprolol can cross the blood brain barrier and may give extra CNS benefits over the atenolol. To check CNS benefits of Metoprolol over atenolol, heart rate variability was assessed during stress and exercise, in this study both atenolol and Metoprolol did attenuate heart rate variability, but there was no difference between them. This suggested that, when CNS is active there is no clinical appreciable extra action of Metoprolol over atenolol click here  from circulation.

There are no RCTs to compare head to head atenolol versus Metoprolol in treatment of hypertension in terms out comes, but retrospective registry analysis have shown either of the molecules is same in treating hypertension  click here. In this study there was no difference in CV events, morality and stroke between atenolol and Metoprolol.

In a study comparing vascular effects of Atenolol versus Metoprolol click here.  Atenolol showed increased peripheral augmentation index as compared to Metoprolol. This increase in augmentation index is associated increased CV events according some studies but few other studies are against this opinion. The increase in augmentation index with atenolol is due to decreased heart rate and increased peripheral vascular resistance.  I think when atenolol or Metoprolol is not used as first line drug, when ether is combined with Ca channel or other vasodilators, benefits of Metoprolol over atenolol in terms vascular benefits may not be that significant.

Atenolol combination with amlodipine is also much cheaper than Metoprolol so I think at least in patients with poor financial status this drug could be still used.