FDA label 1249a39f-b686-5f6d-e054-00144ff8d46c

WARNINGS SPECIAL WARNING ON INCREASED RISK OF CARDIOVASCULAR MORTALITY: 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 non-insulin-dependent diabetes. The study involved 823 patients who were randomly assigned to one of four treatment groups. ( Diabetes , 19 (supp. 2): 747-830, 1970.) 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 2 1 / 2 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 tolazamide 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.

ADVERSE REACTIONS Tolazamide tablets have generally been well tolerated. In clinical studies in which more than 1,784 diabetic patients were specifically evaluated for incidence of side effects only 2.1% were discontinued from therapy because of side effects. Hypoglycemia See PRECAUTIONS and OVERDOSAGE sections. Gastrointestinal Reactions Cholestatic jaundice may occur rarely; tolazamide tablets should be discontinued if this occurs. Gastrointestinal disturbances, e.g., nausea, epigastric fullness, and heartburn, are the most common reactions and occurred in 1% of patients treated during clinical trials. They tend to be dose related and may disappear when dosage is reduced. Dermatologic Reactions Allergic skin reactions, e.g., pruritus, erythema, urticaria, and morbilliform or maculopapular eruptions, occurred in 0.4% of patients treated during clinical trials. These may be transient and may disappear despite continued use of tolazamide; if skin reactions persist, the drug should be discontinued. Porphyria cutanea tarda and photosensitivity reactions have been reported with sulfonylureas. Hematologic Reactions Leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia, aplastic anemia, and pancytopenia have been reported with sulfonylureas. Metabolic Reactions Hepatic porphyria and disulfiram-like reactions have been reported with sulfonylureas; however, disulfiram-like reactions with tolazamide have been reported very rarely. Cases of hyponatremia have been reported with tolazamide and all other sulfonylureas, most often in patients who are on other medications or have medical conditions known to cause hyponatremia or increase release of antidiuretic hormone. The syndrome of inappropriate antidiuretic hormone (SIADH) secretion has been reported with certain other sulfonylureas, and it has been suggested that these sulfonylureas may augment the peripheral (antidiuretic) action of ADH and/or increase release of ADH. Miscellaneous Weakness, fatigue, dizziness, vertigo, malaise and headache were reported infrequently in patients treated during clinical trials. The relationship to therapy with tolazamide is difficult to assess.