Parecoxib Dexamethasone

CORTICOSTEROIDS ANALGESICS-NSAIDs 1. T risk of gastrointestinal ulceration and bleeding 2. Parecoxib levels may be 1 by dexamethasone 1. Additive effect 2. Dexamethasone induces CYP3A4-mediated metabolism of parecoxib 1. Watch for early signs of gastrointestinal upset remember that corticosteroids may mask these features 2. Watch for poor response to parecoxib... 

Enzyme inducers. The effects of the enzyme inducers carbamazepine, dexamethasone, phenytoin and rifampicin have not been studied with parecoxib. Nevertheless, the manufacturer of parecoxib warns that they may increase the metabolism of valdecoxib. ... 

As parecoxib is rapidly metabolised to valdecoxib, the interactions are usually considered to be due to the effects of valdecoxib. The manufacturer of parecoxib cautions the concurrent use with carbamazepine, dexamethasone and rifampicin as their effects on parecoxib have not been studied. Valdecoxib increases the levels of dextromethorphan and omeprazole. Because of these interactions, caution is advised with drugs that are metabolised by the same isoenzymes, nameiy flecainide, metoprolol, propafenone, omeprazoie, diazepam, imipramine and phenytoin. No interaction appears to occur between parecoxib and midazolam. 

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