Tiagabine interactions

Valproate Tiagabine Interaction described in vivo remains to be clarified Valproate displaces tiagabine from plasma binding sites in vitro... 

Drug/Food interactions A high-fat meal decreases the rate, but not the extent (AUC), of tiagabine absorption. 

II.e. 5.2. Interactions between first and second generation AEDs. Felbamate raises plasma concentrations of phenytoin, valproic acid and carbamazepine. Clearance of tiagabine, topiramate and zon-isamide is increased in the presence of an enzyme inducer. Vigabatrin reduces phenytoin concentrations after 4-5 weeks of comedication (via an unknown mechanism). For tiagabine, the elimination half-life may be reduced by 2-3 hours in the presence of an enzyme-induction AED. Lamotrigine elimination is slower if given with valproic acid. Topiramate reduces elimination of phenytoin. 

Tiagabine Blocks GABA reuptake in forebrain by Well absorbed highly bound to plasma proteins extensively Partial seizures Toxicity Nervousness, dizziness, depression, seizures Interactions ... 

Jonker DM, Vermeij DA, Edelbroek PM, Voskuyl RA, Piotrovsky VK, Danhof M. 2003. Pharmacodynamic analysis of the interaction between tiagabine and midazolam with an allosteric model that incorporates signal transduction. Epilepsia 44 329-338. 

Snel S, Jansen JA, Pedersen PC, Jonkman JH, van Heiningen PN. Tiagabine, a novel antiepileptic agent lack of pharmacokinetic interaction with digoxin. Fur J Qin Pharmacol 1998 54(4) 355-7. 

Thomsen MS, Groes L, Agerso H, Kruse T. Lack of pharmacokinetic interaction between tiagabine and erythromycin. J Clin Pharmacol 1998 38(ll) 1051-6. 

The most important interactions of tiagabine involve induction of its metabolism by enzyme-inducing anticonvulsants (30). This results in larger tiagabine dosage requirements compared with patients taking monotherapy or valproic acid co-medication. 

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. ... 

I Advantages. Tiagabine has a specific, known mechanism of action. It is the first drug marketed in the United States that acts only on GABA reuptake. This drug has linear pharmacokinetics and is not reported to interact with other drugs. 

Because of its inducing effect on hepatic enzymes, phenobarbitai has many drug interactions, decreasing plasma levels of CBZ, valproate, lamotrigine, tiagabine, zonisamide, warfarin, theophylline, cimetidine, and those of other CYP3A4 substrates. Serum concentrations of phenobarbitai are increased by valproate. 

Moderate social drinking does not appear to affect the serum levels of carbamazepine, ethosuximide or phenytoin. Some small changes are seen in the serum levels of phenobarbital and sodium valproate, but no changes in the control of epilepsy seem to occur. No pharmacokinetic interaction was detected between tiagabine and alcohol, and tiagabine did not alter the cognitive effect of alcohol. The adverse effects of both alcohol and antiepileptics, such as enhanced sedation, may be additive. 

KastbergH, Jansen JA, ColeG, WesnesK. Tiagabine absence ofkinetic or dynamic interactions with ethanol. DrugMetdbol Drug Interact 99Z) 14,259-73. 

The pharmacokinetics of tiagabine were not altered by cimetidine or erythromycin. No clinically relevant pharmacokinetic interactions occur between tiagabine and theophylline or warfarin. 

Multiple dose studies in healthy subjects have also excluded any clinically relevant pharmacokinetic interactions between tiagabine and theophylline or warfarin but no further study details were given. ... 

Snel S, Jonkman JHG, van Heiningen PNM, Jansen JA, Mengel HB. Tiagabine evaluation of risk of interaction with cimetidine in healthy male volunteers. Epilepsia (1994) 35 (Suppl 7), 74. 

Gustavson LE, Sommerville KW, Boellner SW, Witt GF, Guenther HI, Granneman GR. Lack of a clinically significant pharmacokinetic drug interaction between tiagabine and valproate. AmJTher 99%) 5, 73-79,... 

Studies in healthy subjects have excluded any pharmacodynamic interaction between tiagabine and triazolam. ... 

Richens A, Ivtiirshdll RW, Dirach J, Jansen JA, Snel S, Pedersen PC. Absence of interaction between tiagabine, a new antiepileptic drug, and the ben xliazepine triazolam. DrugMetol Drug Interact ( m) 14,159-77. 

There is little evidence to suggest that carbamazepine interacts with digoxin, and topiramate causes only a small reduction in digoxin serum levels. Levetiracetam and tiagabine do not appear to interact with digoxin. 

Mengel HB, Houston A, Back DJ. An evaluation of the interaction between tiagabine and oral contraceptives in female volunteers. JPham Med (1994) 4,141-50. 

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