WARNINGS
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS
Hypoglycemia
All sulfonylurea drugs, including GLUCOTROL XL, are capable of producing severe hypoglycemia [see ADVERSE REACTIONS]. Concomitant use of GLUCOTROL XL with other anti-diabetic medication can increase the risk of hypoglycemia. A lower dose of GLUCOTROL XL may be required to minimize the risk of hypoglycemia when combining it with other anti-diabetic medications.
Educate patients to recognize and manage hypoglycemia. When initiating and increasing GLUCOTROL XL in patients who may be predisposed to hypoglycemia (e.g., the elderly, patients with renal impairment, patients on other anti-diabetic medications) start at 2.5 mg. Debilitated or malnourished patients, and those with adrenal, pituitary, or hepatic impairment are particularly susceptible to the hypoglycemic action of anti-diabetic medications. Hypoglycemia is also more likely to occur when caloric intake is deficient, after severe or prolonged exercise, or when alcohol is ingested.
The patient's ability to concentrate and react may be impaired as a result of hypoglycemia. Early warning symptoms of hypoglycemia may be different or less pronounced in patients with autonomic neuropathy, the elderly, and in patients who are taking beta-adrenergic blocking medications or other sympatholytic agents. These situations may result in severe hypoglycemia before the patient is aware of the hypoglycemia.
These impairments may present a risk in situations where these abilities are especially important, such as driving or operating other machinery. Severe hypoglycemia can lead to unconsciousness or convulsions and may result in temporary or permanent impairment of brain function or death.
Hemolytic Anemia
Treatment of patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency with sulfonylurea agents, including GLUCOTROL XL, can lead to hemolytic anemia. Avoid use of GLUCOTROL XL in patients with G6PD deficiency. In post marketing reports, hemolytic anemia has also been reported in patients who did not have known G6PD deficiency.
Increased Risk Of Cardiovascular Mortality With Sulfonylureas
The administration of oral hypoglycemic drugs has been reported to be associated with increased cardiovascular mortality as compared to treatment with diet alone or diet plus insulin. This warning is based on the study conducted by the University Group Diabetes Program (UGDP), a long-term prospective clinical trial designed to evaluate the effectiveness of glucose-lowering drugs in preventing or delaying vascular complications in patients with type 2 diabetes mellitus. The study involved 823 patients who were randomly assigned to one of four treatment groups.
UGDP reported that patients treated for 5 to 8 years with diet plus a fixed dose of tolbutamide (1.5 grams per day) had a rate of cardiovascular mortality approximately 2½ times that of patients treated with diet alone. A significant increase in total mortality was not observed, but the use of tolbutamide was discontinued based on the increase in cardiovascular mortality, thus limiting the opportunity for the study to show an increase in overall mortality. Despite controversy regarding the interpretation of these results, the findings of the UGDP study provide an adequate basis for this warning. The patient should be informed of the potential risks and advantages of glipizide and of alternative modes of therapy.
Although only one drug in the sulfonylurea class (tolbutamide) was included in this study, it is prudent from a safety standpoint to consider that this warning may also apply to other oral hypoglycemic drugs in this class, in view of their close similarities in mode of action and chemical structure.
Macrovascular Outcomes
There have been no clinical studies establishing conclusive evidence of macrovascular risk reduction with GLUCOTROL XL or any other anti-diabetic drug.
Gastrointestinal Obstruction
There have been reports of obstructive symptoms in patients with known strictures in association with the ingestion of another drug with this non-dissolvable extended release formulation. Avoid use of GLUCOTROL XL in patients with preexisting severe gastrointestinal narrowing (pathologic or iatrogenic).
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
A twenty month study in rats and an eighteen month study in mice at doses up to 75 times the maximum human dose revealed no evidence of drug-related carcinogenicity. Bacterial and in vivo mutagenicity tests were uniformly negative. Studies in rats of both sexes at doses up to 20 times the human dose based on body surface area, showed no effects on fertility.
Use In Specific Populations
Pregnancy
Risk Summary
Available data from a small number of published studies and postmarketing experience with GLUCOTROL XL use in pregnancy over decades have not identified any drug associated risks for major birth defects, miscarriage, or adverse maternal outcomes. However, sulfonylureas (including glipizide) cross the placenta and have been associated with neonatal adverse reactions such as hypoglycemia. Therefore, GLUCOTROL XL should be discontinued at least two weeks before expected delivery (see Clinical Considerations). Poorly controlled diabetes in pregnancy is also associated with risks to the mother and fetus (see Clinical Considerations). In animal studies, there were no effects on embryofetal development following administration of glipizide to pregnant rats and rabbits during organogenesis at doses 833 times and 8 times the human dose based on body surface area, respectively. However, increased pup mortality was observed in rats administered glipizide from gestation day 15 throughout lactation at doses 2 times the maximum human dose based on body surface area (see Data).
The estimated background risk of major birth defects is 6-10% in women with pre-gestational diabetes with a HbA1c >7 and has been reported to be as high as 20-25% in women with HbA1c >10. The estimated background risk of miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Clinical Considerations
Disease-Associated Maternal and/or Embryo/Fetal Risk
Poorly-controlled diabetes in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, miscarriage, preterm delivery, stillbirth, and delivery complications. Poorly controlled diabetes increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity.
Fetal/Neonatal Adverse Reactions
Neonates of women with gestational diabetes who are treated with sulfonylureas during pregnancy may be at increased risk for neonatal intensive care admission and may develop respiratory distress, hypoglycemia, birth injury, and be large for gestational age. Prolonged severe hypoglycemia, lasting 4-10 days, has been reported in neonates born to mothers receiving a sulfonylurea at
the time of delivery and has been reported with the use of agents with a prolonged half-life. Observe newborns for symptoms of hypoglycemia and respiratory distress and manage accordingly.
Dose Adjustments During Pregnancy and the Postpartum Period
Due to reports of prolonged severe hypoglycemia in neonates born to mothers receiving a sulfonylurea at the time of delivery, GLUCOTROL XL should be discontinued at least two weeks before expected delivery (see Fetal/Neonatal Adverse Reactions).
Data
Animal Data
In teratology studies in rats and rabbits, pregnant animals received daily oral doses of glipizide during the period of organogenesis at doses up to 2000 mg/kg/day and 10 mg/kg/day (approximately 833 and 8 times the human dose based on body surface area), respectively. There were no adverse effects on embryo-fetal development at any of the doses tested. In a peri-and postnatal study in pregnant rats, there was a reduced number of pups born alive following administration of glipizide from gestation day 15 throughout lactation through weaning at doses ≥5 mg/kg/day (about 2 times the recommended maximum human dose based on body surface area).
Lactation
Risk Summary
Breastfed infants of lactating women using GLUCOTROL XL should be monitored for symptoms of hypoglycemia (see Clinical Considerations). Although glipizide was undetectable in human milk in one small clinical lactation study; this result is not conclusive because of the limitations of the assay used in the study. There are no data on the effects of glipizide on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for GLUCOTROL XL and any potential adverse effects on the breastfed child from GLUCOTROL XL or from the underlying maternal condition.
Clinical Considerations
Monitoring for Adverse Reactions
Monitor breastfed infants for signs of hypoglycemia (e.g., jitters, cyanosis, apnea, hypothermia, excessive sleepiness, poor feeding, seizures).
Pediatric Use
Safety and effectiveness in children have not been established.
Geriatric Use
There were no overall differences in effectiveness or safety between younger and older patients, but greater sensitivity of some individuals cannot be ruled out. Elderly patients are particularly susceptible to the hypoglycemic action of anti-diabetic agents. Hypoglycemia may be difficult to recognize in these patients. Therefore, dosing should be conservative to avoid hypoglycemia
[see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS and CLINICAL PHARMACOLOGY].
Hepatic Impairment
There is no information regarding the effects of hepatic impairment on the disposition of glipizide. However, since glipizide is highly protein bound and hepatic biotransformation is the predominant route of elimination, the pharmacokinetics and/or pharmacodynamics of glipizide may be altered in patients with hepatic impairment. If hypoglycemia occurs in such patients, it may be prolonged and appropriate management should be instituted [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS and CLINICAL PHARMACOLOGY].