Transient gastrointestinal adverse events characteristic of GLP-1 receptor agonists were more frequent with exenatide than glargine ( nausea : 36 [ 15 % ] of 233 patients vs five [ 2 % ] of 223 ; vomiting : 15 [ 6 % ] vs six [ 3 % ] ; diarrhoea : 32 [ 14 % ] vs 15 [ 7 % ] ) , although frequency of these events did decrease after week 26 in the exenatide group .