Book of Medical Disorders in Pregnancy - Tintash

in a randomized design the efficacy of
metformin versus insulin use. Because
there is no clinical study to date
reporting on the use of thiazolidinediones
in pregnancy, these agents should
not be prescribed.
Glyburide is the most common oral
agent used in GDM and is whole
heartedly endorsed by authoritative
organizations. The drug increases insulin
secretion and diminishes insulin
resistance by lowering glucose toxicity.
Its onset of action is 4 hours, and its
duration of action is 10 hours.
Thus, after achieving the targeted therapeutic
level, glyburide covers the basal
requirement as well as postprandial glucose
excursions.
The starting dose is 2.5 mg orally in the
morning. If the targeted level of
glycemia is not attained, add 2.5 mg to
the morning dose. If indicated (after 3–7
days), add 5 mg in the evening. There
after, increase the dose in 5/mg
increments to a maximum of 20 mg/day.
If the patient does not achieve targeted
levels of glycemic control, add longacting
insulin to the regimen or assign
the patient to insulin therapy alone. In
one randomized study in 2000, they
enrolled 440 women between 11 and 33
weeks' gestation with singleton pregnancies
that had GDM requiring treatment
(failed oral glucose tolerance test and
fasting plasma glucose level of 95–140
mg/dl). Patients were randomly assigned
to receive either glyburide (n = 201
initial dose 2.5 mg orally, increasing by
5 mg to a total of 20 mg) or insulin (n =
203; initial dose 0.7 units/kg subcutaneously
3 times/daily, increasing
each week as necessary) for glycemic
control. Subjects were required to
measure
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Insulin:
It is not the type of insulin used which
matters; instead it is the quality of
metabolic control, and supervision of the
patient which is of utmost importance.
The urine must be kept free of acetone,
and heavy precipitates of sugar in the
urine are undesirable.
The most significant guide to therapy
with insulin and diet is the two hours
post prandial blood sugar level. The
target should be to maintain this level
between 100 to 120 mg. per cent.
Pregnant women usually require insulin
where diabetes was discovered before
pregnancy, or before 20 weeks of
gestation and when blood glucose levels
are over 150 mgm per cent after meals,
and in patients taking blood glucose
lowering agents before pregnancy.
Actions:
Insulin is responsible for translocation of
glucose and amino acids, and transfer of
potassium in muscles. In liver it also
helps in translocation of glucose and
amino acids, as well as incorporation of
amino acids into peptides. The enzyme
glucokinase increases due to the action
of insulin. In adipose tissue it is
responsible for translocation of glucose
and escape of free fatty acids.
Lente insulin or NPH: This has a
maximum blood glucose lowering effect
from 8 to 14 hours after injection with
decreasing action over night to 24 hours.
The dose should be assessed by the 4.00
p.m. blood sugar and by urine tests done
before supper, at bedtime and before
breakfast. If this blood glucose test is
over 145 mgm% or urine tests done are
over a trace at supper, bedtime and
before breakfast for two days, the dose is
increased by 10% the following