Monthly Archives: July 2013

A new drug (Mirabegron) for Overactive Bladder: That is it?

Traditionally, Overactive Bladder (OAB) symptoms are being treated mainly by anticholinergic medications. The side effect of anticholinergic medications (like dryness of mouth, constipation etc.) is one of the main reasons for their discontinuation. Recently, a new drug called Mirabegron is available for the treatment of OAB (J Urol. 2013 Apr;189(4):1388-95. doi: 10.1016/j.juro.2012.10.017. Epub 2012 Oct 16). Its mechanism of action is completely different from anticholinergic medications because it is β3-adrenoceptor agonist. A randomized, double blind, placebo controlled trial was conducted in USA and Canada in patients with symptoms of OAB for 3 months or more. They were randomized in placebo, 50 mg and 100 mg of Mirabegron once daily for 12 weeks. Primary end points were changes in number of incontinence episodes per 24 hours and micturitions per 24 hours and these were significantly less (p<0.05) in Mirabegron group. The incidence of side effects like dryness of mouth, constipation, hypertension, urinary infection etc were comparable to placebo. The Mirabegron was approved by US Food and Drug Administration (FDA) last year. In summary, this drug has same or better efficacy than placebo and older drugs and furthermore has almost no significant major side effects.

I hope Mirabegron will turn out to be a turning point for the OAB management and can confidently be prescribed in any group of patients without fear of significant side effects. The clinical data are strongly suggestive that it will be a wonderful drug. Hopefully, Mirabegron will be “that is it” for OAB treatment.

PSA and Prostate Cancer: What is new?

PSA and new guidelines for Prostate cancer screening by American Urological Association (AUA)

On May 03, 2013, AUA issued a new guideline for Prostate cancer screening. The purpose of this guideline is to reduce prostate cancer related mortality by addressing early detection of Prostate cancer.  The AUA panel recommend against PSA (Prostate Specific Antigen) screening in men < 40 years because there is low prevalence of clinically detectable Prostate cancer and there is no evidence showing benefit of PSA screening.  Furthermore, they also do not recommend routine PSA screening in men ages 40-54 years at average risk. If these men are at high risk (e.g. positive family history or African American race) then PSA screening should be individualized. The greatest benefits of screening seems to be for men ages 55 –69 years and panel strongly recommend for shared decision making for PSA screening in these age group. For men who decided for screening, screening interval of 2 years is preferred over annual screening in order to reduce harms of screening like overdiagnosis and false positives. Lastly, the AUA panel does not recommend routine PSA screening for men ages >70 years or for any men with life expectancy of less than 10-15 years. This new guideline is based on evidence from systemic literature reviews and replaces the previous AUA guidelines.

I think this new guideline is a fine balance between over and under screening. I hope that with these recommendations, more and more patients will be benefited from PSA screening and at the same time the potential harms from it can be minimised.