RESUMO
Benztropine mesylate (intravenous [IV] and oral) challenge was compared with brief neuroleptic withdrawal on dyskinesia ratings and symptom measures. Thirty-six neuroleptic-treated patients underwent a placebo-controlled acute IV challenge with 2 mg benztropine and a placebo-controlled two-week trial of oral benztropine mesylate (2 mg three times a day), followed by a double-blind placebo-controlled neuroleptic withdrawal involving four weeks of dose tapering and six weeks of placebo treatment. Benztropine given IV had no significant effect. Orally administered benztropine, however, led to statistically significant increases in dyskinesia and dysphoric mood. The brief neuroleptic withdrawal significantly increased dyskinesia scores and dysphoria and resulted in early termination of therapy in 12 of 36 patients (33%) due to symptom exacerbation. There was a striking absence of correlation between dyskinesia change measures brought about by benztropine and changes following neuroleptic withdrawal. Therefore anticholinergic challenge does not appear to be a fruitful procedure for identifying patients with covert dyskinesia.
Assuntos
Antipsicóticos/administração & dosagem , Benzotropina , Discinesia Induzida por Medicamentos/diagnóstico , Síndrome de Abstinência a Substâncias/diagnóstico , Tropanos , Administração Oral , Adulto , Idoso , Antipsicóticos/efeitos adversos , Benzotropina/administração & dosagem , Benzotropina/análogos & derivados , Doença Crônica , Método Duplo-Cego , Discinesia Induzida por Medicamentos/etiologia , Discinesia Induzida por Medicamentos/psicologia , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Placebos , Escalas de Graduação Psiquiátrica , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Síndrome de Abstinência a Substâncias/etiologiaRESUMO
Benzodiazepines have several advantages over other antidyskinetic drugs in treating tardive dyskinesia. The authors conducted a controlled study of clonazepam versus the active placebo of phenobarbital in 21 psychiatric patients with tardive dyskinesia. Both drugs significantly reduced dyskinetic movements: clonazepam had a stronger effect on orofacial dyskinesia, and phenobarbital was more effective for limbs and axial movements. Clonazepam was also more effective for drug-free patients and those receiving low doses of neuroleptics than for all patients given phenobarbital and for clonazepam patients taking high doses of neuroleptics. The authors suggest that future treatment studies focus on the effects of antidyskinetic drugs on distinct body regions.
