Diclofenac Colestyramine

Simultaneous colestyramine marked reduced the absorption of diclofenac and sulindac, modestly reduced the absorption of ibu-profen, but only delayed and did not reduce the extent of absorption of naproxen. Administration of colestyramine three or more hours after oral sulindac, piroxicam, or tenoxicam still markedly reduced their plasma levels. Markedly reduced NSAID levels have also been found when colestyramine is given after intravenous meloxicam or tenoxicam. 

A single-dose, crossover study in 6 healthy, fasting subjects found that the simultaneous use of colestyramine 8 g markedly reduced the AUC of a single 100-mg oral dose of enteric-coated diclofenac by 62% and reduced its maximum plasma levels by 75%. Colestipol 10 g reduced the diclofenac AUC by 33% and its maximum plasma levels by 58%. ... 

The studies of simultaneous oral use suggest that the anion exchange resin colestyramine, and to a lesser extent colestipol, bind anionic NSAIDs (e.g. diclofenac) in the gut, so reducing their absorption. The studies showing reduced plasma levels when colestyramine was given after intravenous oxicams or separated by at least 3 hours from some oral NSAIDs, suggest that colestyramine can reduce the enterohepatic recirculahon of these drugs. 

Established interactions. Colestyramine markedly reduces the initial absorption of some NSAIDs (shown for diclofenac), and if these NSAIDs also undergo enterohepatic recirculation, their clearance will also be increased (shown for meloxicam, piroxicam, sulindac, and tenoxicam). This latter interaction cannot be avoided by separating the doses, and it may be best not to use colestyramine with these NSAIDs. Colestyramine can be used to speed the removal of piroxicam and tenoxicam following overdosage. Diclofenac has been formulated with colestyramine in an attempt to reduce gastric mucosal damage by reducing direct mucosal contact 140 mg of diclofenac-colestyramine is considered equivalent to 70 mg of diclofenac. ... 

---

See also in sourсe #XX -- [ ]

---