Candesartan vs Losartan: And the Winner Is . . .

All drug manufacturers would have you believe that their drug is distinctly different from all the others in the same class.  Pharmaceutical benefit managers would like you to believe that it's a class effect such that one (less expensive generic) drug can be substituted for another (more expensive brand) within the same class.  But who's right?

From my perspective, it appears that most manufacturers have some sort of gentleman's agreement to compare their products to placebos rather than their competitors so that it's often very difficult if not impossible to directly compare apples to apples.  Instead, we compare each product's efficacy to placebo vs another product's efficacy to placebo.  Or they focus on different outcomes (and even this changes w/time).

For instance, back in the day, the Zocor rep would discuss at length all the clinical outcome studies regarding their product.  On the other hand, the Lipitor rep would talk about how their product lowered LDL better than any drug on the market (this was in the pre-Crestor days).  Nowadays, however, the table's been turned.  Now the Lipitor rep talks about all the clinical outcome studies regarding their product while it's the Crestor rep who discusses how their product lowers LDL better than any drug on the market.  Yet, one rarely sees a direct head-to-head comparison of Crestor vs Lipitor regarding what really counts:  all-cause mortality, or at least cardiovascular mortality.

Therefore, I was quite surprised to see a study published this last week in JAMA comparing candesartan (2,639 patients) to losartan (2,500 patients) in those patients with heart failure w/reduced left ventricular ejection fraction followed for 5 years.   Their conclusion?  Lower all-cause mortality in those patients taking candesartan!

Now, before you start switching all your patients from any other ACE inhibitor and/or ARB to candesartan, realize that this population studied was a non-randomized registry (and not a randomized controlled trial) so there is plenty of room for tremendous bias.  However, as the authors concluded, there exists strong evidence that candesartan has benefits not found in other ARBs.  Only time and at least one randomized double blind placebo controlled trial will tell.  In the meantime, if I'm given a choice between candesartan & losartan . . .