Baclofen (Lioresal) in the treatment ofneuroleptic-induced tardive dyskinesia.

A double-blind cross-over trial of the effects of baclofen and placebo was carried out in 20 female patients suffering from neuroleptic-induced tardive dyskinesia. After 14 days of treatment 15 patients showed improvement of baclofen, whereas none showed improvement on placebo; baclofen was thus significantly more effective than placebo. Baclofen is a GABA-like drug which passes through the blood-brain barrier and which reduces the neuroleptic-induced increase of dopamine turn-over. In tardive dyskinesia is found dopaminergic hypersensitivity, and baclofen is supposed to exert its action by inhibiting the dopamine activity. Side effects, although temporary, were observed in the form of sedation, muscular hypotonia, dizziness, vomiting, and muscular rigidity. One patient developed a depression. Baclofen or other gabergic drugs used in the treatment of dyskinesias do not increase the dopaminergic hypersensitivity, which is part of the pathogenesis of these conditions; gabergic therapy must therefore be preferred to treatment with dopamine receptor blocking drugs.