PRECAUTIONS
General
Macrovascular Outcomes: There have been no clinical studies establishing
conclusive evidence of macrovascular risk reduction with DIABINESE (chlorpropamide) or any other
anti-diabetic drug.
Hypoglycemia: All sulfonylurea drugs including chlorpropamide
are capable of producing severe hypoglycemia, which may result in coma, and
may require hospitalization. Patients experiencing hypoglycemia should be managed
with appropriate glucose therapy and be monitored for a minimum of 24 to 48
hours (see OVERDOSAGE section). Proper patient selection, dosage, and
instructions are important to avoid hypoglycemic episodes. Regular, timely carbohydrate
intake is important to avoid hypoglycemic events occurring when a meal is delayed
or insufficient food is eaten or carbohydrate intake is unbalanced. Renal or
hepatic insufficiency may affect the disposition of DIABINESE (chlorpropamide) and may also diminish
gluconeogenic capacity, both of which increase the risk of serious hypoglycemic
reactions. Elderly, debilitated or malnourished patients, and those with adrenal
or pituitary insufficiency are particularly susceptible to the hypoglycemic
action of glucose-lowering drugs. Hypoglycemia may be difficult to recognize
in the elderly, and in people who are taking beta-adrenergic blocking drugs.
Hypoglycemia is more likely to occur when caloric intake is deficient, after
severe or prolonged exercise, when alcohol is ingested, or when more than one
glucose-lowering drug is used.
Because of the long half-life of chlorpropamide, patients who become hypoglycemic during therapy require careful supervision of the dose and frequent feedings for at least 3 to 5 days. Hospitalization and intravenous glucose may be necessary.
Loss of control of blood glucose: When a patient stabilized on
any diabetic regimen is exposed to stress such as fever, trauma, infection,
or surgery, a loss of control may occur. At such times, it may be necessary
to discontinue DIABINESE (chlorpropamide) and administer insulin.
The effectiveness of any oral hypoglycemic drug, including DIABINESE (chlorpropamide) , in lowering blood glucose to a desired level decreases in many patients over a period of time, which may be due to progression of the severity of the diabetes or to diminished responsiveness to the drug. This phenomenon is known as secondary failure, to distinguish it from primary failure in which the drug is ineffective in an individual patient when first given. Adequate adjustment of dose and adherence to diet should be assessed before classifying a patient as a secondary failure.
Hemolytic Anemia: Treatment of patients with glucose 6-phosphate dehydrogenase
(G6PD) deficiency with sulfonylurea agents can lead to hemolytic anemia. Because
DIABINESE (chlorpropamide) belongs to the class of sulfonylurea agents, caution should be used
in patients with G6PD deficiency and a non-sulfonylurea alternative should be
considered. In post marketing reports, hemolytic anemia has also been reported
in patients who did not have known G6PD deficiency.
Geriatric Use
The safety and effectiveness of DIABINESE (chlorpropamide) in patients aged 65 and over has not been properly evaluated in clinical studies. Adverse event reporting suggests that elderly patients may be more prone to developing hypoglycemia and/or hyponatremia when using DIABINESE (chlorpropamide) . Although the underlying mechanisms are unknown, abnormal renal function, drug interaction and poor nutrition appear to contribute to these events.
Laboratory Tests
Blood glucose should be monitored periodically. Measurement of glycosylated hemoglobin should be performed and goals assessed by the current standard of care.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Studies
with DIABINESE (chlorpropamide) have not been conducted to evaluate carcinogenic or mutagenic
potential.
Rats treated with continuous DIABINESE (chlorpropamide) therapy for 6 to 12 months showed varying
degrees of suppression of spermatogenesis at a dose level of 250 mg/kg (five
times the human dose based on body surface area). The extent of suppression
seemed to follow that of growth retardation associated with chronic administration
of high-dose DIABINESE in rats. The human dose of chlorpropamide is 500 mg/day
(300 mg/M2). Six- and 12-month toxicity work in the dog and rat,
respectively, indicates the 150 mg/kg is well tolerated. Therefore, the safety
margins based upon body-surf ace-area comparisons are three times human exposure
in the rat and 10 times human exposure in the dog.
Pregnancy
Teratogenic Effects
Pregnancy Category C. Animal reproductive studies have not been conducted with DIABINESE (chlorpropamide) . It is also not known whether DIABINESE (chlorpropamide) can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. DIABINESE (chlorpropamide) should be given to a pregnant woman only if the potential benefits justify the potential risk to the patient and fetus.
Because data suggest that abnormal blood glucose levels during pregnancy are associated with a higher incidence of congenital abnormalities, many experts recommend that insulin be used during pregnancy to maintain blood glucose levels as close to normal as possible.
Nonteratogenic Effects
Prolonged severe hypoglycemia (4 to 10 days) has been reported in neonates born to mothers who were receiving a sulfonylurea drug at the time of delivery. This has been reported more frequently with the use of agents with prolonged half-lives. If DIABINESE (chlorpropamide) is used during pregnancy, it should be discontinued at least one month before the expected delivery date and other therapies instituted to maintain blood glucose levels as close to normal as possible.
Nursing Mothers
An analysis of a composite of two samples of
human breast milk, each taken five hours after ingestion of 500 mg of chlorpropamide
by a patient, revealed a concentration of 5 mcg/mL. For reference, the normal
peak blood level of chlorpropamide after a single 250 mg dose is 30 mcg/mL.
Therefore, it is not recommended that a woman breast feed while taking this
medication.
Use in Children
Safety and effectiveness in children have not
been established.
Ability to Drive and Use Machines
The effect of DIABINESE (chlorpropamide) on
the ability to drive or operate machinery has not been studied. However, there
is no evidence to suggest that DIABINESE (chlorpropamide) may affect these abilities. Patients
should be aware of the symptoms of hypoglycemia and take caution while driving
and operating machinery.