Baclofen + Tizanidine - Drug Interactions

Clinical evidence,mechanism, importance and management

In a randomised,three-period study, 15 healthy subjects were given baclofen 10mg three times daily and tizanidine 4mg three times daily, together and alone, for 7 consecutive doses. None of pharmacokinetic parameters of either drug were changed by more than 30%, a figure calculated to indicate presence of an interaction (See reference number 1). No changes in dosages of either drug are therefore likely to be needed if they are taken concurrently.

1. Shellenberger MK,Groves L, Shah J, Novak GD. A controlled pharmacokinetic evaluation oftizanidine and baclofen at steady state. Drug Metab Dispos (1999) 27, 201–204.