Priapism ziprasidone

Priapism Rare cases of priapism have been associated with risperidone, ziprasidone, quetiapine, aripiprazole, and olanzapine. 

In one case, priapism followed the use of first risperidone and then ziprasidone (534). 

A 22-year-old African-American with chronic undifferentiated schizophrenia developed priapism after taking risperidone 4 mg bd, clonazepam 0.5 mg bd, vitamin E 400 IU bd, and a multivitamin for over 6 months. He did not respond to subcutaneous terbuta-line 0.25 mg. Irrigation of the corpora with phenylephrine 200 p resulted in detumescence risperidone was withdrawn. A few months later he took ziprasidone 20 mg bd for 1 week, clonazepam 1 mg bd, and vitamin E 400 IU bd. The ziprasidone dosage was increased to 40 mg bd, but early the next morning he developed a firm erection with some discomfort that lasted about 2 hour and resolved when he urinated the next morning he had a similar erection that also lasted 2 hour and resolved. 

In one case priapism followed the use of first risperidone and then ziprasidone YET TO start HERE(197). In two other cases, presumed to be due to risperidone (198,199), penile irrigation with isotonic saline and phenylephrine injection resulted in detumescence. Risperidone has a high affinity for alpha-1 adrenoceptors, and alpha-1 blockade leads to direct arteriolar dilatation, which results in increased blood inflow and reduced outflow secondary to effacement and subsequent obstruction of emissary veins. 

A 50-year-old male with previous history of priapism and prior use of sildenafil presented with ischaemic priapism requiring surgical intervention. The patient had been on ziprasidone and sodium divalproex for 6 years. There was no change in dose but within 24 h of switching to co-ingesting ziprasidone with food he experienced... 

Denton K, KoUi V, Sharma A. Ziprasidone-induced ischemic priapism requiring surgical intervention a case report. Prim Care Companion CNS Disord 2013 15(1). 

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