Add-on cilostazol potentially alleviates primary negative symptoms of schizophrenia
An 8-week treatment course with cilostazol as an adjunct to risperidone demonstrates a favourable safety and efficacy profile in patients with schizophrenia, improving primary negative symptoms without resulting in serious adverse events requiring medical intervention, a study has shown.
A total of 84 patients with chronic schizophrenia were randomized to receive 8 weeks of treatment with either cilostazol (50 mg twice daily; n=42; mean age 37.4 years; 22.7 percent female) or placebo (n=42; mean age 36.19 years; 22.7 percent female) as an add-on to risperidone. Assessment of the positive and negative syndrome scale (PANSS) was performed at baseline and at weeks 2, 4, 6 and 8. The main outcome measure was the PANSS negative subscale score.
In a general linear model repeated measures, a significant effect for time × treatment interaction was observed on negative subscale and PANSS total scores (p<0.001 and p=0.006, respectively) but not on the PANSS positive and general subscale scores (p=0.37 and p=0.06, respectively).
Compared with those on placebo, patients on cilostazol showed significantly greater improvement in the PANSS total score (mean change from baseline, 17.04 vs 11.42; p=0.01) and negative subscale scores (mean change from baseline, 4.85 vs 2.54; p<0.001) at week 8.
Frequency of adverse events did not significantly differ between the two treatment groups. No serious adverse event was observed.
The present data lend support to the notion that cilostazol can help improve the negative symptoms of schizophrenia, researchers said. However, more studies with larger sample size and longer treatment periods are needed to examine the long‐term safety, efficacy and optimal dosage of the drug.
Primary negative symptoms of schizophrenia are not secondary to extrapyramidal, depressive or positive symptoms, but are instead the core features of schizophrenia. The symptoms—which include deficits in social and emotional functioning, blunted affect and lack of spontaneity—are associated with long‐term functional disability and poor outcome. [Schizophrenia Bulletin 2006;32:214–219; CNS Drugs 2003;17:793–823]