I’ve previously written about incretins and the role of incretin mimetics in diabetes treatment. The other part of that, of course, is that you can inhibit the breakdown of the body’s natural incretins to prolong their effect. This is what the dipeptylpeptidase-4 inhibitors, or gliptins, do.
Unlike GLP-1 analogues they can be taken orally; unlike most diabetic drugs, they’re weight-neutral. Like GLP-1 analogues, they are unlikely to cause hypoglycaemia. They are therefore most useful as dual therapy with metformin where hypoglycaemia is likely to be a particular problem (people who work on heights or with machinery, elderly people living alone), and can also be used as second-line dual therapy where sulphonylureas are not tolerated (much more uncommon) or don’t achieve sufficient HbA1c reduction. They can also be used as triple therapy, though at the time the article was written (May 2011) sitagliptin was the only one with a licence for this purpose.
There is a theoretical risk of pancreatitis, but no known cases had been reported at the time of the article. There was likewise no information on long-term outcomes at that point. Main side-effects are headache & N&V, and the drugs are generally well tolerated.
(Prescriber, 5th May 2o11)