Sitagliptin

Category: pharmacological

Aliases: Januvia, MK-0431

Pharmacological Mechanism

Competitive, reversible DPP-4 (dipeptidyl peptidase-4) inhibitor — blocks degradation of the endogenous incretins GLP-1 and GIP, raising their plasma levels 2–3× and potentiating glucose-dependent insulin release plus glucagon suppression. Weight-neutral, low hypoglycaemia risk (glucose-dependent action). CV-neutral (TECOS trial).

Half-Life (t½)

PO: 10.4h

Dosing Guidelines

• PO: Typical 100 mg (Range: 100–100 mg)

Target Organ Systems

• endocrine

Interactions

• Metformin (synergistic): Standard dual-therapy combination; Janumet combines the two.
• Semaglutide / GLP-1 RAs (caution): Overlapping incretin mechanism — generally not combined (redundant PD + additive GI).

Pathways It Modulates

• Insulin signaling + glucose homeostasis (inhibitor) — DPP-4

Chemical Identifiers

• PubChem CID: 4369359
• Formula: C16H15F6N5O
• Molecular weight: 407.31 g/mol
• InChIKey: MFFMDFFZMYYVKS-SECBINFHSA-N
• SMILES: C1CN2C(=NN=C2C(F)(F)F)CN1C(=O)C[C@@H](CC3=CC(=C(C=C3F)F)F)N

References

• PMID 17220239
• PMID 15634008