Treatment of severe psychosis with risperidone

A new oral formulation of the antipsychotic medication risperidone has been found to be effective in treating acute severe psychosis in schizophrenic patients.

Severe acute psychosis is a medical emergency, requiring rapid and effective management. Traditional treatment of acute severe psychosis has included intramuscular injection of a high-strength typical antipsychotic, such as haloperidol. This approach has several disadvantages: it requires an injection to be given, there is an increased risk of side effects, and there is an increased risk of mental or physical trauma to the patient. In addition, typical antipsychotics are now only infrequently used in long-term treatment of psychotic disorders like schizophrenia. This means that once a patient has overcome the acute episode, their medication usually needs to be changed from a typical antipsychotic to a newer, atypical antipsychotic.

The study

Risperidone (Risperdal) is an atypical antipsychotic drug. It is used to treat psychiatric diseases such as schizophrenia. A new, fast-acting orally disintegrating form of risperidone has been developed. This new formulation dissolves rapidly in the mouth and provides an oral alternative to intramuscular injections for the treatment of severe acute psychosis.

Researchers in this open-label observational trial studied 191 patients with an acute psychosis. Of these 191 patients, most (152 patients) had a diagnosis of paranoid-hallucinatory schizophrenia. Other patients had diagnoses of schizoaffective disorder, acute psychotic disorder, and drug-induced psychosis.

Patients were treated with fast orally disintegrating risperidone, in doses ranging from 1 to 9mg/day. The effects of risperidone were measured using the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impressions Scale for Severity (CGI-S) and Change (CGI-G).

Results

Risperidone was found to be clinically effective in the treatment of acute severe psychosis. At the beginning of the study, PANSS total scores were 114.3 +/- 23.4, indicating severe psychosis. At seven days, the PANSS score was significantly reduced to 83.6 +/- 26.8 (p < 0.0001). CGI scores were significantly reduced from 5.6 +/- 0.7 at the commencement of the study to 4.5 +/- 1.1 (P < 0.0001) at 7 days. Risperidone was also fast-acting, with a median time to calmness of 70 minutes after administration.

Co-medication

Most (72.8%) of patients receiving risperidone as part of this study were also given one other medication to treat psychosis. The commonest co-medication used was lorazepam, a benzodiazepine (sedative). Analysis of this group found that patients receiving risperidone and a benzodiazepine had a more rapid response than patients receiving risperidone alone. The median time to calmness in the dual treatment group was 65 minutes, compared to 90 minutes for patients receiving only risperidone. At one week, however, there was no significant difference in total PANSS or CGI-S scores between the two groups. This suggests that risperidone is safe and effective in combination with benzodiazepines.

Side effects

One in five (21.5%) of patients experienced at least one adverse event during the study. The commonest adverse events were extra-pyramidal disorder (a type of movement disorder), hypotension (low blood pressure) and obstipation (severe constipation). Overall, only three of 191 patients discontinued treatment with risperidone due to side effects.

Conclusion

Fast orally disintegrating risperidone tablets are a safe and effective treatment for acute severe psychosis. The tablets have a fast onset of action and are acceptable to both patients and psychiatrists.