Glyburide is an oral medication of the sulfonyl-urea class
used to lower blood sugar. The drug acts by stimulating pancreatic islet cells
to increase insulin secretion. Glyburide is highly bound to proteins in the
blood. The action of glyburide may be enhanced by other drugs that are also highly protein bound such as beta blockers.
Pfizer lists glyburide (Micronase ®) as a pregnancy category B drug [1]. Other
manufacturers list the drug as category C.
Glyburide does not cross the human placenta or enter human breast milk in appreciable
quantities [2-4]. Glyburide appears to be a safe and effective
alternative to insulin in the treatment of gestational diabetes for some women.
However, patients with diabetes prior to
pregnancy, a history of diabetic ketoacidosis, liver disease, or a fasting blood
sugar greater than or equal to 140 mg/dL are treated more appropriately with insulin
[5-9]. Women with an OGTT less than 200 mg/dL, a fasting blood sugar less than
110 mg/dL, and who fail dietary therapy after 30 weeks gestation do well on
glyburide therapy [9-12].
The usual starting dose of glyburide is 2.5 mg orally
daily. When indicated, the dose of glyburide may be increased the following week
by 2.5 mg and thereafter by 5 mg weekly up to a total of 20 mg when necessary to achieve glycemic control. [6]
The onset of action occurs within 2
hours, with a maximal decrease in blood sugar occurring within 3 to 4 hours. The blood glucose
lowering effect lasts for 24 hours following a single morning dose in nonfasting diabetic patients.
The most commonly reported adverse events in patients taking glyburide have been nausea, heart burn, low blood sugar, muscle pain, joint pain, and allergic skin reactions including angioedema (swelling similar to hives) . Blurred vision has been reported with glyburide which is thought to be related to unstable blood sugar values. Liver problems including jaundice and hepatitis may also occur. Less commonly porphyria cutanea tarda, an abnormal sensitivity of the skin to sunlight, hyponatremia, a decrease in the number of agranulocyte white cells in the blood, thrombocytopenia, hemolytic anemia, aplastic anemia, and pancytopenia have been reported with sulfonylureas. Disulfiram-like reactions have been reported very rarely.[1]
Patients treated with glyburide for the control of gestational diabetes are
classified as type A2 diabetes, and should receive the same antenatal
surveillance as patients with A2 diabetes treated with insulin.
REFERENCES
1. Micronase® package insert 2002 www.pfizer.com/pfizer/download/uspi_micronase.pdf
. Accessed 5/18/2007
2. Elliott BD, Langer O, Schenker S, Johnson RF. Insignificant transfer of
glyburide occurs across the human placenta. Am J Obstet Gynecol 1991;165:807-812
PMID: 1951536
3. Elliott BD, et al Comparative placental transport of oral hypoglycemic agents in humans: a model of human
placental drug transfer. Am J Obstet Gynecol. 1994;171:653-60.
PMID: 8092211
4. Feig DS, Briggs GG, Kraemer JM et al. Transfer of glyburide and
glipizide into breast milk. Diabetes Care. 2005;28:1851-5. PMID:
16043722
5. ACOG Practice Bulletin. Clinical management guidelines for
obstetrician-gynecologists. Number 30, September 2001.Gestational diabetes.
Obstet Gynecol. 2001;98:525-38.
PMID:11547793
6.Langer O, Conway DL, Berkus MD, Xenakis EM-J, Gonzalez O.A comparison of
glyburide and insulin in women with gestational diabetes mellitus. N Engl J
Med. 2000 ;343:1134-8.PMID: 11036118
7. Jacobson GF, et al. Comparison of glyburide and insulin for the management
of gestational diabetes in a large managed care organization. Am J
Obstet Gynecol. 2005 Jul;193(1):118-24.
PMID: 16021069
8. Langer O, et al. Insulin and glyburide therapy: dosage, severity level of
gestational diabetes, and pregnancy outcome. Am J Obstet Gynecol.2005;192:134-9.
PMID: 15672015
9. Kahn BF, et al., Predictors of glyburide failure in the treatment of
gestational diabetes. Obstet Gynecol.2006;107:1303-9.
PMID: 16738156
10.
Rochon M , et al.,Glyburide for the management of gestational diabetes: risk
factors predictive of failure and associated pregnancy outcomes.
Am J Obstet Gynecol. 2006 ;195:1090-4.
PMID:
17000241
11.
Conway DL , et al., Use of glyburide for the treatment of gestational diabetes:
the San Antonio experience.
J Matern Fetal Neonatal Med. 2004 ;15:51-5.
PMID:15101612
12.Chmait R, et al. Prospective observational study to establish predictors of
glyburide success in women with gestational diabetes mellitus.
J Perinatol. 2004;24:617-22. PMID: 15152273
SEE ALSO:
DIABETES IN PREGNANCY
