Clonazepam/haloperidol combination therapy in schizophrenia: a double blind study.

Clonazepam (CLN), a benzodiazepine originally used as an anti-epileptic, was tested in schizophrenia in a double blind comparison in combination with haloperidol (HL). Twenty-four schizophrenic inpatients, diagnosed according to DSM III were treated with HL and CLN (Group 1) or HL and placebo (Group 2) for 4 weeks. The Brief Psychiatric Rating Scale (BPRS) and the Extrapyramidal Side Effect Scale (EPSE) were used for assessing psychopathological features and extrapyramidal side-effects before treatment and then weekly. No differences in specific schizophrenic symptoms were detected between the two groups, but in Group 1 an early significant BPRS amelioration was noticed compared to Group 2. Moreover, the excitement item improved significantly in Group 1 only, from the second week. Less severe EPSE scores were observed in Group 1 in comparison to Group 2. In conclusion the combination of CLN and HL seems to be preferred to HL alone in cases of psychotic excitement and in order to reduce the severity of extrapyramidal side-effects.