Nausea was the most common adverse event in the AMIGO studies, with
most episodes being mild to moderate; progressive dose escalation
lessened its incidence. Nausea was the reason for a drop-out rate of up
to 4% in the 10µg group. Patients also taking sulfonylureas experienced
a higher incidence of hypoglycemia than those taking either metformin
or placebo. Exenatide has been shown to be non-inferior to insulin aspart
and glargnine in terms of HbA1c reduction and has helped reduce
bodyweight, while insulin therapy was associated with significant weight
gain.37,38 Thirty post-marketing reports of acute pancreatitis and six cases
of hemorrhagic or necrotizing pancreatitis have been reported in patients
taking exenatide. No definitive causal relationship between exenatide
and pancreatitis has been established; however, the FDA felt it prudent
to issue a safety warning relating to these rare adverse events.39 There is
some evidence that exenatide may exhibit a disease-modifying effect.
Recent preliminary studies in patients who have undergone pancreatic
islet transplants indicated that exenatide enhanced glycemic response
and HbA1c levels.40 It has also been shown to restore the insulin secretion
patterns, similar to those observed in subjects with no diabetes.41