Adverse effects, as noted in previous studies, were common. Of the 121 patients who were initially randomly assigned to receive exenatide, only 86 (71%) completed the 16 weeks of the trial, compared with 96 of 122 (79%) of patients receiving placebo. Nausea and vomiting were statistically significantly higher in patients receiving exenatide and were the most common reasons for leaving the study (17 of 31 patients). A 26% dropout rate is rarely observed in short-term clinical studies of antidiabetic drugs. The authors state that many patients dropped out during the initial dose escalation of exenatide and, with time, fewer patients left the study. The reduction of these adverse drug reactions with time could be due to better tolerance. Alternatively, it could be due to a form of survivor bias, wherein patients who were less prone to nausea and vomiting stayed in the study. Because dose increments are necessary to produce the reported results, high rates of desertion are likely when exenatide is used in the general diabetic population. The authors did not provide information about subgroups that were more prone to develop adverse drug reactions. Adverse effects are clearly a substantial problem with exenatide, and physicians considering prescribing exenatide will need help in managing them. The authors collected this information. They should publish it.