Last Updated: 03/15/04 06:40 PM

Switch to Human Insulin Worries Some Diabetics

Mike Mitka 

JAMA, 13 January, 1999, vol. 281, #2 p121-2

ELI LILLY AND COMPANY STOPPED manufacturing mixed beef-pork insulins in October of last year. This means only human-based insulin will be available in the United States, and that scares 43-year-old Lucy Hartley.

Hartley, of Buies Creek, NC, is an in insulin-dependent diabetic who has used Lilly's Iletin I beef-pork-based insulin for 32 years. Ten years ago, her endocrinologist switched her to Humulin, Lilly 's human-based insulin.

"The results were disastrous," she re called in a letter sent to JAMA. "The changes in my overall feeling of well-being were immediate. The experience I had with Humulin was negative overall, ranging from loss of what had been relatively good diabetic control, to feeling 'strange' in general, to experiencing the more serious hypoglycemic 'unawareness' episodes. In 20-plus years with diabetes, I had never lost consciousness because of a hypoglycemic reaction until I switched from Iletin-I to Humulin."

And now Hartley must resume taking human-based insulin because Lilly estimates its supply of the animal-based product will last only into the second quarter of this year. But a Lilly physician and others said the switch to human-based insulin should not be a major problem.


The biggest fear among users of animal-based insulin making the change is hypoglycemia unawareness-the concern that with human-based insulin, they may develop hypoglycemia without the neurogenic warning symptoms they are familiar with. Those symptoms allow diabetic persons to take countermeasures, such as drinking orange juice, before the hypoglycemia worsens. [Conclusive proof that Mr. Mitka is totally clueless about the issues on which he is writing since the neurogenics, like confusion, disorientation, change of personality, inability to think or concentrate are actually signs, not symptoms and likely do more damage than good. Ed.]

"One of my patients who switched almost drove off the George Washington Bridge-he had no warning," said Rhoda Cobin, MD, a Midlands Park, NJ, endocrinologist. "Although hypoglycemia unawareness is real, it's not because of an inherent difference in the effect of the insulin but people may experience a difference in the time course of the two products. Human insulin may act sooner and its duration of action may be shorter so one has to monitor oneself more frequently."

John Holcomb, MD, a senior clinical research physician at Lilly, said current research shows that switching to human-based insulin does not cause hypoglycemia unawareness."

Ask patients if there's a difference in unawareness and they say 'yes"' Holcomb said. "But switch them in a blinded trial, and they can't tell the difference" (Lancet. 1992:339: 1432-1435, and Diabet Med. 1994;1 1:925-934). He agreed that the key is to get the dosing. timing, and self-monitoring correct to make the changeover successful. [If we accept enormous sample sizes like 7, he may be smoking something we should all get from him. Ed.]

Holcomb said Lilly ended production of its beef-pork insulin because fewer thin 5% (about 100 000) of insulin users take it and because the company couldn't economically maintain its 25 different formulations for such a Small and declining Percentage of the population with diabetes. He also noted that human-based insulin is now the world standard and offers benefits over animal-based insulin, such as fewer and less frequent allergic reactions and avoidance of tissue changes at the site of injection. [The man is lying on all scores, but that's what he's paid to do for Lilly, isn't it? Ed.]


The American Diabetes Association (ADA) endorsed the switchover. "Human insulin has become the insulin of first choice for newly diagnosed patients with diabetes and is recommended by the [ADA] for patients beginning insulin therapy. Human INSULINS give patients more choices for their insulin therapy and this can lead to improved lives for people with diabetes,' the association said in a statement. [The ADA is lying. Ed.]

But is the ADA concerned that there may be an increase this summer of "dead-in-bed" syndrome that diabetics face?

"We're a little nervous," said Richard Kahn, PhD, the ADA's chief scientific and medical officer. "But biologically there should be no reason why you can't switch over. Now, there are patients who claim they can't switch. We don't know why that's so, but they should be working with their [physicians] to adjust dosage and other aspects,"

Despite all the assurances from the medical profession Lucy Hartley still worries and wonders why any change is necessary. I don't know if I will die," she said. "But I do know the switch will drastically change my lifestyle and make it less pleasant. I think of medicine as trying to make people have as normal a life as possible. I won't have that without my beef-pork insulin."

Tips for Easing the Transfer to Human Insulin

  • Patients transferring from animal to human insulin usually begin with the same dosing regimen and an equivalent number of units.
  • Some patients, however, who take human insulin may require a change in dosage from that used with animal-source insulins- If an adjustment is needed, it may occur with the first close or during the first several weeks or months.
  • Patients receiving more than 100 U of Iletin (animal-source) insulin per day should begin human Insulin with a 20% lower dose
  • Patients should frequently monitor their blood glucose levels, and insulin adjustments should be made based on blood glucose measurement.
  • The adjustment period may last up to 6 weeks.
  • Potential adverse effects associated with the use of all insulins include hypoglycemia, weight gain, hypokalemia, lipodystrophy, and hypersensitivity.
  • Any change in insulin therapy should always be done under a physician's supervision.

Source: Eli Lilly and Company