Diabetes Demands a Triad of Treatments
Shot of Insulin
The first insulin for diabetes was derived
from the pancreas of cows and pigs. Today, chemically synthesized human insulin
is the most often used. It is prepared from bacteria with DNA technology. Human
insulin is not necessarily an advantage over animal insulin, and most doctors
don't recommend that patients on animal insulin automatically switch to human
insulin. But if they do switch, dosages may change. Human insulin is preferred
for those patients who take insulin intermittently.
According to Robert Misbin, M.D., medical
officer for metabolic and endocrine drug products in FDA's Center for Drug
Evaluation and Research and a practicing physician, some diabetics take beef
insulin for religious reasons because of dietary restrictions against pork.
"But the vast majority of insulin-dependent diabetics take synthesized
human insulin," he says. "Those who are taking a beef or pork insulin
and doing well -- you don't necessarily change the type of insulin they take.
But for new patients I see, I would start them on human
Diabetics on intensified insulin therapy --
that is, those needing multiple daily injections or an insulin pump, which is
worn 24 hours a day -- can have flexibility in when and what they eat. Other
diabetics on insulin therapy must eat at consistent times, synchronized with
the time-action of the insulin they use.
In 1996, FDA approved Humalog, which Misbin
describes as "a modified human insulin." Humalog is absorbed and
dissipated more rapidly than regular human insulin. Misbin says that Humalog is
of particular benefit to Type I diabetics who are on very strict
Julio V. Santiago, M.D., director of the
Diabetes Research and Training Center at Washington University's School of
Medicine in St. Louis, notes that Humalog is most helpful for diabetics
monitoring their blood sugar levels and taking three or more injections of
insulin a day. He reports switching most of his Type I patients who fit that
profile to the new insulin.
Four classes of oral diabetes drugs are now
available. The oldest class, sulfonylureas (SFUs), act on the pancreatic tissue
to produce insulin. The newest one is Glimepiride, approved by FDA in