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Alvimopan
- indication:Used to accelerate the time to upper and lower gastrointestinal recovery following partial large or small bowel resection surgery with primary anastomosis. Also investigated for use in the treatment of pain (acute or chronic).
- pharmacologypharmacology:
- mechanism: Alvimopan competitively binds to mu-opioid receptor in the gastrointestinal tract. Unlike methylnaltrexone (another peripherally acting mu-receptor antagonist) that bears a quaternary amine, alvimopan owes its selectivity for peripheral receptors to its kinetics. Alvimopan binds to peripheral mu-receptors with a Ki of 0.2 ng/mL and dissociates slower than most other ligands.
- toxicity:
- absorprion: Alvimopan's high affinity for the peripheral mu-receptor results in an absolute oral bioavailability of less than 7%.
- halflife: 10 to 17 hours (gut metabolite: 10 to 18 hours)
- roouteelimination: Biliary secretion was considered the primary pathway for alvimopan elimination. Unabsorbed drug and unchanged alvimopan resulting from biliary excretion were then hydrolyzed to its ‘metabolite’ by gut microflora.
- volumedistribution: * 30±10 L
- clearance: * 402 +/- 89 mL/min