David's New Book

Friday, June 22, 2012

Generic Antibiotics - Which Way is Up?



In a number of previous blogs, I have noted the apparently hypocritical and inconsistent approach taken by the FDA regarding old approvals of generic antibiotics.  Recently, the FDA was awakened from its long sleep by an article in the New England Journal of Medicine on an old macrolide antibiotic, azithromycin.  In the study, the authors show that there is an elevated, but very small risk of cardiac arrhythmias from taking azithromycin – a potential already recognized by the FDA and already noted in all labeling for macrolide antibiotics.  The FDA responded to the article by noting its intention to relabel azithromycin and other macrolide antibiotics.  But at the same time, the FDA reasserts its approval of use of azithromycin and other macrolide antibiotics for
·      Acute bacterial exacerbations of chronic bronchitis
·      Acute bacterial sinusitis
·      Uncomplicated skin infections.
But – STOP THE PRESSES!  Uncomplicated skin infection no longer exists as an indication for the FDA.  The so called mild respiratory infections now require placebo-controlled trials to prove benefit over risk – while here the FDA is noting increased risk but they already state that for these mild respiratory infections – no placebo-controlled trial = no proof of benefit.  Therefore, these indications should logically now be withdrawn for all macrolide antibiotics.  And here is the perfect opportunity – an example of potentially increased risk.   What is the FDA doing?

Of course the FDA is completely and totally aware of the apparent paradox in their approach to generics – but they refuse to do anything.  There is nothing new about this.  The only thing new here is the reminder that, in fact, the reality is that they will not touch generics in any meaningful way while, at the same time, they restrict entry of new antibiotics to indications that physicians and patients still find useful even if the FDA does not (acute otitis media – great entry into pediatrics; acute bacterial sinusitis and acute bacterial exacerbations of COPD).  Without some drugs approved to treat these infections – all use – and there is a ton of it – would be off label.  We wouldn’t want that (or would we?).

By the way – in this case, the FDA in the US and the EMA in Europe are on the same page – I just think it’s the wrong page.

If you are confused by the approach of the regulatory agencies to generic antibiotics – welcome to my world.