Macrovascular Outcomes: There have been no clinical studies establishing conclusive evidence of macrovascular risk reduction with Starlix or any other antidiabetic drug.
Hypoglycemia: All oral blood glucose lowering drugs that are absorbed systemically are capable of producing hypoglycemia. The frequency of hypoglycemia is related to the severity of the diabetes, the level of glycemic control, and other patient characteristics. Geriatric patients, malnourished patients, and those with adrenal or pituitary insufficiency or severe renal impairment are more susceptible to the glucose lowering effect of these treatments. The risk of hypoglycemia may be increased by strenuous physical exercise, ingestion of alcohol, insufficient caloric intake on an acute or chronic basis, or combinations with other oral antidiabetic agents. Hypoglycemia may be difficult to recognize in patients with autonomic neuropathy and/or those who use beta-blockers. Starlix® (nateglinide) should be administered prior to meals to reduce the risk of hypoglycemia. Patients who skip meals should also skip their scheduled dose of Starlix to reduce the risk of hypoglycemia.
Hepatic Impairment: Starlix should be used with caution in patients with moderate-to-severe liver disease because such patients have not been studied.
Loss of Glycemic Control
Transient loss of glycemic control may occur with fever, infection, trauma, or surgery. Insulin therapy may be needed instead of Starlix therapy at such times. Secondary failure, or reduced effectiveness of Starlix over a period of time, may occur.
Information for Patients
Patients should be informed of the potential risks and benefits of Starlix and of alternative modes of therapy. The risks and management of hypoglycemia should be explained. Patients should be instructed to take Starlix 1 to 30 minutes before ingesting a meal, but to skip their scheduled dose if they skip the meal so that the risk of hypoglycemia will be reduced. Drug interactions should be discussed with patients. Patients should be informed of potential drug-drug interactions with Starlix.
Response to therapies should be periodically assessed with glucose values and HbA1C levels.
Nateglinide is highly bound to plasma proteins (98%), mainly albumin. In vitro displacement studies with highly protein-bound drugs such as furosemide, propranolol, captopril, nicardipine, pravastatin, glyburide, warfarin, phenytoin, acetylsalicylic acid, tolbutamide, and metformin showed no influence on the extent of nateglinide protein binding. Similarly, nateglinide had no influence on the serum protein binding of propranolol, glyburide, nicardipine, warfarin, phenytoin, acetylsalicylic acid, and tolbutamide in vitro. However, prudent evaluation of individual cases is warranted in the clinical setting.
Certain drugs, including nonsteroidal anti-inflammatory agents (NSAIDs), salicylates, monoamine oxidase inhibitors, and non-selective beta-adrenergic-blocking agents may potentiate the hypoglycemic action of Starlix and other oral antidiabetic drugs.
Certain drugs including thiazides, corticosteroids, thyroid products, and sympathomimetics may reduce the hypoglycemic action of Starlix and other oral antidiabetic drugs.
When these drugs are administered to or withdrawn from patients receiving Starlix, the patient should be observed closely for changes in glycemic control.
The pharmacokinetics of nateglinide were not affected by the composition of a meal (high protein, fat, or carbohydrate). However, peak plasma levels were significantly reduced when Starlix was administered 10 minutes prior to a liquid meal. Starlix did not have any effect on gastric emptying in healthy subjects as assessed by acetaminophen testing.
Carcinogenesis/Mutagenesis/Impairment of Fertility
Carcinogenicity: A two-year carcinogenicity study in Sprague-Dawley rats was performed with oral doses of nateglinide up to 900 mg/kg/day, which produced AUC exposures in male and female rats approximately 30 and 40 times the human therapeutic exposure respectively with a recommended Starlix dose of 120 mg, three times daily before meals. A two-year carcinogenicity study in B6C3F1 mice was performed with oral doses of nateglinide up to 400 mg/kg/day, which produced AUC exposures in male and female mice approximately 10 and 30 times the human therapeutic exposure with a recommended Starlix dose of 120 mg, three times daily before meals. No evidence of a tumorigenic response was found in either rats or mice.
Mutagenesis: Nateglinide was not genotoxic in the in vitro Ames test, mouse lymphoma assay, chromosome aberration assay in Chinese hamster lung cells, or in the in vivo mouse micronucleus test.
Impairment of Fertility: Fertility was unaffected by administration of nateglinide to rats at doses up to 600 mg/kg (approximately 16 times the human therapeutic exposure with a recommended Starlix dose of 120 mg three times daily before meals).
Pregnancy Category C
Nateglinide was not teratogenic in rats at doses up to 1000 mg/kg (approximately 60 times the human therapeutic exposure with a recommended Starlix dose of 120 mg, three times daily before meals). In the rabbit, embryonic development was adversely affected and the incidence of gallbladder agenesis or small gallbladder was increased at a dose of 500 mg/kg (approximately 40 times the human therapeutic exposure with a recommended Starlix dose of 120 mg, three times daily before meals). There are no adequate and well-controlled studies in pregnant women. Starlix should not be used during pregnancy.
Labor and Delivery
The effect of Starlix on labor and delivery in humans is not known.
Studies in lactating rats showed that nateglinide is excreted in the milk; the AUC0-48h ratio in milk to plasma was approximately 1:4. During the peri- and postnatal period body weights were lower in offspring of rats administered nateglinide at 1000 mg/kg (approximately 60 times the human therapeutic exposure with a recommended Starlix dose of 120 mg, three times daily before meals). It is not known whether Starlix is excreted in human milk. Because many drugs are excreted in human milk, Starlix should not be administered to a nursing woman.
The safety and effectiveness of Starlix in pediatric patients have not been established.
No differences were observed in safety or efficacy of Starlix between patients age 65 and over, and those under age 65. However, greater sensitivity of some older individuals to Starlix therapy cannot be ruled out.