@fdixon63 , I have taken Myrbetriq for more than a year and have found it is quite successful at relieving OAB. I have not experienced any interactions with lamotrigine, the only other prescription drug I take. Myrbetriq is, indeed quite "spendy" running into thousands of dollars per year without the benefit of insurance. The there are several patents for mirabegron that won't expire until the 2030's, so I am looking into the several substitutes like oxybutynin that are available.