Transient dystonias in three patients treated with tiagabine.

PURPOSE

Tiagabine (TGB) is a new antiepileptic drug (AED) with gamma-aminobutyric acid (GABA)ergic mechanism of action. GABAergic compounds may influence the extrapyramidal system, probably via modulation of dopaminergic nigrostriatal neurons. A well-known side effect of TGB is probably dose-related extrapyramidal tremor. To our knowledge, acute dystonias associated with TGB treatment have yet to be described.

METHODS

Three patients with transient acute dystonic reactions while taking TGB as add-on therapy with carbamazepine (CBZ) are presented. The focal limb dystonia in one case, an oromandibular dystonia in second, and writer's cramp in third one were observed.

RESULTS

In all cases dystonic movements resolved spontaneously without discontinuation of TGB therapy and without any concomitant treatment.

CONCLUSIONS

Tiagabine may cause various mild extrapyramidal side effects. All three cases reported were diagnosed with transient possibly drug-related dystonia after increase in TGB dose. It remain unclear whether dystonic movements are specific for patients treated with TGB/CBZ bitherapy.