SITAGLIPTIN

SITAGLIPTIN (sit-a-glip'tin) Januvia Classifications: hormone modifier; antidiabetic agent; dipeptidyl peptidase-4 (dpp-4) inhibitor; incretin modifier; Therapeutic:antidiabetic; incretin modifier; dpp-4 inhibitor Pregnancy Category: B

Availability

25 mg, 50 mg, and 100 mg tablets

Action

Sitagliptin slows inactivation of incretin hormones [e.g., glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)] that are released by the intestine. As plasma glucose rises, incretin hormones stimulate release of insulin from the pancreas, and GLP-1 also lowers glucagon secretion, resulting in reduced hepatic glucose production.

Therapeutic Effect

Sitagliptin elevates the level of incretin hormones, thus increasing insulin secretion and reducing glucagon secretion. Sitagliptin lowers both fasting and postprandial plasma glucose levels.

Uses

Adjunct treatment of type 2 diabetes mellitus in combination with exercise and diet.

Contraindications

Type I diabetes mellitus, diabetic ketoacidosis. Safety and efficacy in children <18 y are not known.

Cautious Use

Moderate to severe renal impairment, renal failure, hemodialysis; older adults; pregnancy (category B), lactation.

Route & Dosage

Type 2 Diabetes Mellitus Adult: PO 100 mg/d Renal Impairment Clcr >30 mL/min and <50 mL/min: 50 mg/d <30 mL/min: 25 mg/d

Administration

Oral

• May be given without regard to meals.
• Note that dosage adjustment is recommended for moderate to severe renal impairment.
• Store at 20°–25° C (68°–77° F).

Adverse Effects (≥1%)

CNS: Headache. Respiratory: Nasopharyngitis, upper respiratory tract infection.

Interactions

Drug: Sitagliptin may increase digoxin levels.

Pharmacokinetics

Absorption: 87% absorbed. Peak: 1–4 h. Distribution: 38% protein bound. Metabolism: 20% metabolized in the liver. Elimination: Primarily renal (87%) with minor elimination in the kidneys. Half-Life: 12.4 h.

Nursing Implications

Assessment & Drug Effects

• Monitor for and report S&S of significant GI distress, including NV&D.
• Monitor for S&S of hypoglycemia when used in combination with a sulfonylurea drug or insulin.
• Lab tests: Baseline and periodic Cl_cr; periodic fasting and postprandial plasma glucose and HbA_1C.
• Monitor blood levels of digoxin with concurrent therapy.

Patient & Family Education

• Follow directions for taking the drug (see Administration).
• Note: When taken alone to control diabetes, sitagliptin is unlikely to cause hypoglycemia because it only works when your blood sugar is rising.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug