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Drugs reference index «Sitagliptin Phosphate»

Sitagliptin Phosphate

Pronunciation: (SI-ta-GLIP-tin FOS-fate)Class: Antidiabetic agent

Trade Names:Januvia- Tablets 25 mg- Tablets 50 mg- Tablets 100 mg


Sitagliptin is a dipeptidyl peptidase-4 inhibitor that is believed to act in type 2 diabetes by slowing the inactivation of incretin hormones.



Sitagliptin is rapidly absorbed, with 100 mg reaching a C max of 950 nM in 1 to 4 h. The bioavailability is approximately 87%.


Vd is approximately 198 L. Plasma protein binding is 38%.


Metabolism by CYP3A4 and, to a lesser degree, CYP2C8 is a minor pathway in the Cl of sitagliptin.


Terminal t ½ is approximately 12.4 h. Approximately 13% is excreted in feces and 87% in urine via active tubular secretion (79% as unchanged drug). Sitagliptin is a substrate for organic anion transport.

Indications and Usage

Adjunct to diet and exercise in type 2 diabetes mellitus as monotherapy or in combination with metformin or a thiazolidinedione (eg, rosiglitazone) when the single agent alone, with diet and exercise, does not provide adequate glycemic control.


Standard considerations.

Dosage and Administration


PO 100 mg once daily with or without food.

Renal Function ImpairmentAdults

PO Moderate renal function impairment (CrCl 30 to less than 50 mL/min): 50 mg once daily. Severe renal function impairment (CrCl less than 30 mL/min): 25 mg once daily.

General Advice

  • May be taken with or without food.


Store at 59° to 86°F.

Drug Interactions


Sitagliptin plasma concentrations may be increased modestly (approximately 68%), which is not expected to be clinically important.


Digoxin plasma levels may be increased slightly (approximately 18%); no dosage adjustment is recommended.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Headache (at least 5%).


Nasopharyngitis (at least 5%).


Diarrhea (3%); nausea (1%).


Upper respiratory tract infection (at least 5%).



Category B .




Safety and efficacy not established.

Renal Function

Dosage adjustments are needed in patients with moderate or severe renal function impairment.



Mean increases in QTc interval of 8 msec, which were not considered clinically important, were observed at a dose of 800 mg. There is no experience with doses above 800 mg.

Patient Information

  • Advise patient to read the patient information leaflet before using product the first time and with each refill.
  • Educate patient, family, or caregiver regarding type 2 diabetes and its management.
  • Instruct patient that this drug is not a substitute for diet and exercise and to follow prescribed regimen.
  • Emphasize the importance of regular daily blood glucose monitoring and periodic glycosylated hemoglobin tests.
  • Review symptoms of hypoglycemia and hyperglycemia and action plans to undertake in the event either occur.
  • Instruct patient to report hypoglycemic or hyperglycemic episodes to a health care provider.
  • Advise patient that during periods of stress (eg, fever, trauma, infection, surgery), medication requirements may change and to seek medical advice promptly.

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