Neutral protamine Hagendorn (NPH) insulin contains several components which need to be evenly mixed to be the most effective. If the solution is not mixed well, it can produce potentially severe episodes of hypoglycemia in its users.
In an effort to reduce these hypoglycemic episodes, Peter Jehle, MD, and his colleagues from University Hospital in Ulm, Germany, recommend tipping the insulin pen at least 20 times before injections to ensure an even mix. In research conducted by Jehle that was published in the November 1999 issue of The Lancet, 109 pen cartridges were collected from patients. Jehle reports that only 35 percent of the pens had the correct NPH values. Questioning of patients’ techniques showed that only 9 percent had tipped and rolled their pens more than 10 times.
Jehle reports that suspension errors dropped for 35 out of the 44 patients who were educated on proper tipping techniques. Although HbA1c values for these 35 patients did not change, their rates of hypoglycemia fell significantly.