Orlistat

Category: pharmacological

Aliases: Xenical, Alli

Pharmacological Mechanism

Irreversibly inhibits pancreatic + gastric lipases via covalent serine modification → blocks hydrolysis of dietary triglycerides → ~30% of ingested fat passes unabsorbed. Modest weight loss 3–6% at 1 year. Largely unabsorbed systemically — acts locally in gut lumen.

Half-Life (t½)

PO: 1.5h

Dosing Guidelines

• PO: Typical 60 mg (Range: 60–60 mg)

Target Organ Systems

• cardiovascular
• digestive

Interactions

• Vitamin D3 (caution): Fat-soluble vitamin malabsorption — supplement.

Pathways It Modulates

• GI motility + secretion (inhibitor) — pancreatic + gastric lipase (gut-restricted)

Chemical Identifiers

• PubChem CID: 3034010
• Formula: C29H53NO5
• Molecular weight: 495.74 g/mol
• InChIKey: AHLBNYSZXLDEJQ-FWEHEUNISA-N
• SMILES: CCCCCCCCCCC[C@@H](C[C@H]1[C@@H](C(=O)O1)CCCCCC)OC(=O)[C@H](CC(C)C)NC=O

References

• PMID 8626884