Priapism Associated With the Switch From Oral to Injectable Risperidone

Abstract

Priapism is a rare, but serious, side effect of psychotropic medications. Psychotropic medication-induced priapism is believed to be caused by the alpha-adrenergic antagonism of these medications. Among the atypical antipsychotics, cases of priapism or prolonged erection have been associated with clozapine, olanzapine, risperidone, and quetiapine. Risperidone has primarily serotonergic, dopaminergic, and alpha-adrenergic antagonist properties. It has one of the highest affinities for the alpha1-adrenergic receptor blockade among the atypical antipsychotics. To date, there are 17 case reports of risperidone-associated priapism either in monotherapy or in combination with other psychotropics. To our knowledge, there are no published case reports of priapism on the injectable preparation of risperidone. We report a case of a 50-year-old man who developed priapism while being switched from the oral to the intramuscular preparation of risperidone. The importance of early recognition and intervention in cases of priapism is emphasized. The treatment of priapism with benztropine and other methods is discussed.

Recurrent priapism associated with single dose of paliperidone palmitate: a case report

“…Although there are numerous priapism reports associated with oral antipsychotics, fewer cases are reported with long-acting antipsychotics. 5 To our knowledge this is the first priapism case report under paliperidone palmitate. The fact that priapism is rare side effect and paliperidone is relatively new medication might be a reason why literature may have lack of such cases.…”

Priapism associated with atypical antipsychotic medications: a review

“…Many cases of priapism are found reported with the low potency dopamine receptor antagonists, especially the phenothiazines, chlorpromazine and thioridazine (Thompson et al, 1990;Kirshner and Davis, 2006). These drugs cause higher a-adrenergic blockade than the high potency drugs like haloperidol.…”

“…Risperidone has nearly the highest affinity for the aadrenergic receptor among the atypical antipsychotics and it has been associated with priapism with up to 20 cases (Emed and Dube, 1994;Tekell et al, 1995;Maizel et al, 1996;Nicloson and Mcurley, 1997;Deirmenjian et al, 1998;Owley et al, 2001;Seger and Lamberti, 2001;Ankem et al, 2002;Freudenreich, 2002;Madhusoodan et al, 2002;Reeves and Mack, 2002;Bourgeios and Mundh, 2003;Relan et al, 2003;du Toit et al, 2004;Slauson and Lo Vecchio, 2004;Yang and Tsai, 2004;Kirshner and Davis, 2006;Wang et al, 2006;Haberfellner, 2007;Makesar and Thome, 2007) reported with its use (Table 2). Drug interactions may occur when serotoninspecific reuptake inhibitors like paroxetine are used with risperidone.…”

Quetiapine-induced priapism

“…For the atypical antipsychotics, risperidone and ziprasidone have the highest antagonism at alpha 1 and olanzapine has the lowest [3]. However, there have been several published cases of priapism with other atypical antipsychotics with lower alpha 1-antagonism such as olanzapine, quetiapine, and clozapine [6]. Although alpha 1-adrenergic affinity hypothesis, lower (olanzapine, quetiapine, clozapine) or higher (risperidone, ziprasidon) affinity of the antipsychotics found to be same offenders of priapism.…”