Priapism Associated with Two Atypical Antipsychotic Agents

Abstract

Priapism has been associated with many antipsychotic agents, including clozapine, risperidone, and olanzapine. This prolonged, usually painful, penile erection rarely results from the alpha-adrenergic blocking action of antipsychotics. A 22-year-old African-American man developed priapism during treatment with risperidone and, on a later occasion, during treatment with ziprasidone. The problem resolved only with substitution of other drugs for these antipsychotics. Certain patients may be more vulnerable than others to this adverse effect. Clinicians must be aware of such complications and use caution when prescribing these drugs.

Priapism associated with atypical antipsychotic medications: a review

“…Priapism could be considered an idiosyncratic reaction because it is correlated neither with the dosage of a psychotropic drug nor with the duration of its use (Thompson et al, 1990). Patients who may have an unusual susceptibility to this side effect and develop priapism with the use of numerous different antipsychotics are found (Compton et al, 2000;Reeves and Mack, 2002;du Toit et al, 2004). In one report (du Toit et al, 2004), a 44-year-old man with a 23-year history of schizophrenia, initially developed priapism on a combination of risperidone 8 mg and trazodone.…”

“…Since then there have been 10 reported cases (Rosen and Hanno, 1992;Seftel et al, 1992;Zeigler and Behar, 1992;Barbieri and Dube, 1994;Moinfar et al, 1994;Raja and Azzoni, 2006;Hovermann et al, 1997;Compton et al, 2000;Bongale et al, 2001;Reeves and Mack, 2002;de Nesnera, 2003). This presents a challenge to the psychiatrist who is treating a patient with schizophrenia who has failed trials with other drugs and is treatment resistant.…”

Priapism Associated With the Switch From Oral to Injectable Risperidone

“…6 It has one of the highest affinities for the a 1 -adrenergic receptor blockade among the atypical antipsychotics. 1,7 It also exerts some a 2 antagonism. 1 To date, there are 17 case reports of risperidone-associated priapism either in monotherapy or in combination with other psychotropics.…”

“…1 To date, there are 17 case reports of risperidone-associated priapism either in monotherapy or in combination with other psychotropics. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] 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 injectable long-acting preparation of risperidone.…”

“…Literature describes cases of priapism related to an increase in the dose of the antipsychotic, restarting medications after a period of noncompliance, switching to a different class, or combining antipsychotics. 1,3,7 Although the product monograph for Risperdal Consta states that the main release of the drug starts from 3 weeks onward, there is a small initial release of the drug (up to 1% of the dose). It is possible that even early on when combined with the oral dose, the injectable preparation may exert enough a-adrenergic blockade in the corpora cavernosa to cause priapism.…”