Footnotes Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors Gamma-secretase inhibitor conflict of interest statement: The authors declare that there is no conflict of

interest.
Priapism is a urological emergency defined as persistent penile erection that is unrelated to sexual stimulation [Huang Inhibitors,research,lifescience,medical et al. 2009]. It typically involves the corporal cavernosa [Keoghane et al. 2002]. It can occur as a rare side effect of antipsychotic medications and is thought to be mediated via their α-adrenergic antagonist effect [Spagnul et al. 2011; Andersohn et al. 2010]. In this paper we describe a case of priapism in a patient recently started on risperidone and sodium valproate. We also review the South London and Maudsley (SLAM) Case Register Interactive Inhibitors,research,lifescience,medical Search (CRIS) database to assess how many other cases of priapism were reported in patients taking risperidone. We add this information to a literature review of cases of priapism associated with risperidone, building on the work of Choua and colleagues and Sood and colleagues [Choua et al. 2007; Sood et al. 2008]. Delayed recognition of priapism can have irreversible consequences with up to 50% of affected patients becoming impotent [Choua et al. 2007; Inhibitors,research,lifescience,medical Sood et al. 2008] or in some cases needing penile amputation

[Hoffman et al. 2010] often because they present late. We believe that clinicians reviewing patients for sexual side effects, Inhibitors,research,lifescience,medical recognizing priapism and educating patients on how to distinguish priapism from a normal erection can minimize poor outcomes. Case report Y is a 45-year-old African with a 7-year history of schizoaffective disorder. Since his initial diagnosis, he had never been completely

symptom free and poor Inhibitors,research,lifescience,medical compliance with medication had led to several relapses, hospital admissions and medication changes. He had previously been on various antipsychotics, including olanzapine, haloperidol, flupenthixol depot and trifluoperazine CYTH4 in combination with sodium valproate. His last admission took place at the end of 2010 following concerns that he had stopped his medication (trifluoperazine and sodium valproate) and that his mental state was deteriorating. He was showing signs of self-neglect, fluctuating mood, agitation and irritability. He expressed grandiose delusions, paranoid ideations and had limited insight into his condition. He was started on risperidone 2 mg at night and sodium valproate 750 mg twice daily. One week later, risperidone was increased to 4 mg at night and sodium valproate to 1000 mg twice daily. Y reported a 48 h history of persistent and painful erection 3 days later. He was immediately sent to the emergency department where a diagnosis of low flow priapism was made.