Successful treatment of low-flow priapism associated with phenothiazine therapy


Correspondence: Nobuyuki Kondoh MD, Department of Urology, Hyogo College of Medicine, 1–1 Mukogawa-cho, Nishinomiya City, Hyogo, 663–8501, Japan. Email:


Abstract We present a case of low-flow priapism that was successfully treated. A 21-year-old man with a history of schizophrenia was admitted with a painful complete erection. He had taken propericiazine, phenothiazine derivatives, before hospitalization and was treated with a glandular–cavernosal shunt (El-Ghorab's procedure). Currently, he is able to have erections without any changes in his quality of life.


Priapism is a well-known entity characterized by prolonged pathological erection without sexual stimulation or desire. It is classified into high-flow (non-ischemic) and low-flow (ischemic) types mainly by cavernous blood gas analysis. In the low-flow type, rigidity of the penis is high and often accompanied by severe pain. It causes irreversible changes in the cavernosal tissues unless treated immediately with appropriate therapy. Thus, the low-flow type of priapism is a urological emergency. Priapism is induced by various causes including clinical drugs.1,2

We report a case of low-flow priapism associated with oral medication that was treated successfully using a glandular–cavernosal shunt. We briefly discuss the priapism in relation to phenothiazine therapy.

Case report

A 21-year-old man presented with a sustained, painful and complete erection that had begun 24 h previously on 21 July 1999. He was initially treated at another outpatient clinic where the corpus cavernosum had been punctured, followed by several irrigations with a heparin-containing solution and instillation of α-adrenergic agents. His penis re-erected soon after this treatment. Gas analysis of the cavernous blood showed a PO2 of 9.8 mmHg and a PCO2 of 98.9 mmHg, suggesting venous blood. Moreover, he had a history of schizophrenia and had been taking 10 mg propericiazine, a phenothiazine derivative, orally once a day since October 1998. He had not experienced any episodes of local trauma, genito-urinary infection or hematologic disorder. Since we diagnosed that his priapism was the low-flow (ischemic) type, an emergency operation (glandular–cavernosal shunt) was done according to the El-Ghorab's procedure.3 A 2 cm transverse incision was made in the dorsum of the glans penis, approximately 1 cm from the corona. The distal ends of the corpora cavernosa were identified after a sharp incision of the tissues of the corpora spongiosum (Fig. 1). Then circular incisions were performed in each corpus with the removal of approximately 5 mm of tunica albuginea (Fig. 2). After drainage of the corpora that changed the dark sludged blood to a bright red flow, a running suture with an absorbable thread was used to construct a glandular–cavernosal shunt with the incision on the glans closed. A drip infusion of heparin-containing solution (500 units/h) was started immediately after the operation and stopped within 48 h and gentle pressure was applied to the penis until the next morning. The penis had detumesced 2 days after the operation and normal morning erection was noted. After 1 year of follow up the patient was able to have normal erections and the oral administration of phenothiazine derivatives continued.

Figure 1.

A 2 cm transverse incision of the glans and tissues of the corpus spongiosum exposed the tunica albuginea of the corpus cavernosum.

Figure 2.

An oval resection of approximately 5 mm length on each tunica albuginea of the corpus cavernosum was made. Initial sludged blood soon returned to a bright red flow under mild massage of the penile shaft.


Priapism is defined as a prolonged pathological erection unrelated to sexual desire. According to Hauri et al.,4 it is divided into two types, namely high-flow (non-ischemic) and low-flow (ischemic). Since the crucial point in management of priapism is awareness of the low-flow type as an emergency, the differential diagnosis of the two types should be done as quickly as possible. As was noted in the present case, the low-flow type is often associated with severe pain and relatively higher penile rigidity than the high-flow type. In the case of a penis that is not very rigid with mild pain and a history of penile trauma, the high-flow type of priapism is highly suspected. Color Doppler ultrasonography and cavernosography are helpful aids for proper diagnosis.5 In the present case, the patient's history, symptoms and gas analysis of cavernosal blood suggested the low-flow type so we did not use any other diagnostic methods before carrying out an emergency operation.

The glandular–cavernosal shunt (the El-Ghorab's procedure) is a very useful operative technique. It improves the weak point of relatively low patent efficacy due to the re-obstruction of shunt created by the Winter's procedure.6 The authors previously encountered two patients with low-flow priapism in whom good results were not achieved with Winter's procedure alone; thus, we chose the corporal–spongiosal shunting operation to gain complete detumescence. We selected the El-Ghorab's procedure for the first shunt-creating operation, since almost 24 h had passed from the onset of priapism in this case. Although Ercole et al. mentioned that postoperative pressure to the penis was not necessary,3 we used intermittent pressure to avoid re-closure of the shunt. In regard to postoperative urinary drainage, Ercole et al. recommended a suprapubic cystostomy, but we used a narrow urethral catheter (12-F), which had no adverse effect on the corpus spongiosum.

Priapism is a well-known side-effect of oral medication. The medications most frequently associated with this condition are psychotropic drugs including phenothiazine derivatives. The association of priapism with phenothiazine therapy, as was found in this case, has been well reported.1,7 In the present case, the actual induction of priapism by phenothiazine was not confirmed because of the relatively long-term use of the medication before the onset of priapism. Since previous reports on the onset of priapism after beginning drug therapy ranged from 2 h to several months,8 it is plausible that priapism might be induced by unknown factors combined with the α-adrenergic blocking activity of phenothiazine.

Lastly, we emphasize the usefulness of the El-Ghorab's procedure in terms of erectile function. We previously encountered four cases of priapism in our hospital and in three of the four cases the emergency operations performed were corporal–cavernosal shunts, including Winter's procedure for two patients. However, postoperative erectile function was lost or could not be determined in three of the four cases in spite of the relatively long operation time (data not shown). On the other hand, the present case showed preservation of potency one year postoperatively and we suggest that the El-Ghorab's procedure should be the operation of choice in the case of low-flow priapism due to its effectiveness and usefulness in preserving potency.