Naproxen Valproate

Naproxen Valproate Interaction of little or no clinical significance Displacement from plasma protein binding sites... 

Tiagabine is displaced from protein by naproxen, salicylates, and valproate. 

It is oxidized hy CYP3A4 enzymes, and other drugs may alter its clearance. Tiagahine is displaced from protein hy naproxen, salicylates, and valproate. The minimal effective adult dose level is considered to be 30 mg/day. 

Drug Interactions. Enzyme inducers, such as carbamazepine and phenytoin, increase tiagabine clearance and decrease the half-life. Food decreases the rate but not the extent of absorption. Tiagabine is displaced from protein by naproxen, salicylates, and valproate. However, tiagabine does not displace phenytoin, valproic acid, amitrypty-line, tolbutamide, or warfarin. ... 

Valproate toxicity developed in three patients given large and repeated doses of aspirin. Increased levels of free valproate were found in S children within hours of them taking aspirin. Con-versefy, a slightly reduced valproate level was reported in one patient who took ibuprofen. Modestly altered protein binding has been shown when sodium valproate was given with diflunisal or naproxen, but this appears unlikely to be clinically important... 

A study in 6 healthy subjects found that naproxen 500 mg twice daily moderately decreased the AUC of a single 800-mg dose of sodium valproate by 11%. Similarly, in another study, when naproxen 500 mg twice daily was given with sodium valproate 500 mg twice daily the AUC of valproate was decreased by 20% and the AUC of naproxen was increased by 7%. It is suggested that naproxen and sodium valproate displace each other from their protein binding sites. The clinical relevance of these modest changes is uncertain, but is likely to be small. ... 

Addison RS, Parker-Scott SL, Hooper WD, Eadie MJ, Dickinson RG. Effect of naproxen coadministration on valproate disposition. Biopharm DrugDispos (2000) 21, 235-42. 

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