A cluster of reports of hypersensitivity reactions among patients who switched from
carvedilol (immediate release formulation, referred to hereafter as carvedilol) to carvedilol
extended release was received during the initial post-launch period of carvedilol extended
release. In follow up to this observation, product labeling for both agents was updated and a
nested case control study was subsequently conducted to examine the risk of serious
hypersensitivity reactions i.e. anaphylactic reaction and/or angioedema among patients who
used carvedilol extended release compared to carvedilol and separately compared to other long
acting beta(β)-blockers. This proposed analysis is an update to the previously conducted
analysis using the same database, LabRx, now containing 2 additional years of data, which
should provide a larger number of carvedilol extended release exposed subjects.