Theophylline Improves Hypoglycemic
Unawareness In Type 1's
In diabetic patients with hypoglycemic unawareness
who took theophylline for two weeks, the drug's
effects on glucose counterregulation were sustained
over the course of treatment.
In the July issue of Clinical Pharmacology and
Therapeutics, Dr. Paul Smits and colleagues at
the University Medical Center Nijmegen, The Netherlands,
explain that a single dose of theophylline is
known to improve hypoglycemic unawareness in patients
with type I diabetes. Because tolerance to many
of theophylline's pharmacologic effects emerges
with prolonged use, the researchers sought to
determine whether improvements in hypoglycemic
unawareness would also disappear with extended
administration.
Twelve patients with type I diabetes and hypoglycemic
unawareness participated in a crossover study
in which they took 250 mg of theophylline twice
daily for 15 days, or matching placebo for 15
days. On the final day of each period, hyperinsulinemic,
hypoglycemic clamp studies were performed.
The authors report, "Under hyperglycemic
conditions, theophylline enhanced responses of
growth hormone, symptoms, heart rate, and pulse
pressure (all p < 0.05), induced sweating at
higher plasma glucose levels (p = 0.039) and reduced
exogenous glucose requirements (p = 0.018)."
The drug did not improve responses of epinephrine,
norepinephrine, or cortisol, however.
In summary, the authors write, "Two weeks
of theophylline treatment increased cardiovascular,
thermoregulatory, symptomatic and composite metabolic
responses, but not individual hormone responses,
to hypoglycemia."
They conclude that the results "suggest that
theophylline retains efficacy in supporting glucose
counterregulatory responses to hypoglycemia, despite
long-term use." Clin Pharmacol Ther 2003;74:77-84.
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FACT:
More than 61 percent of adults and 13 percent
of children nationwide are overweight or obese,
making them susceptible to such diseases as hypertension,
diabetes and certain cancers, according to U.S.
Surgeon General Richard H. Carmona.
