Risperidone-induced priapism

Risperidone-induced priapism: a case report and literature review

Priapism is a rare pathological condition defined as painful and persistent penile erection that is unrelated to sexual stimulation. It can be classified as ischaemic or non-ischaemic. Many causes have been attributed to ischaemic priapism, including the use of some medications such as antipsychotics. The mechanism of priapism associated with antipsychotics is thought to be related to alpha-adrenergic blockage that is mediated by the alpha receptors in the corpora cavernosa of the penis. In this paper, we describe a case of a patient who suffered from Risperidone-induced priapism, and how this adverse effect was resolved by switching to olanzapine followed by olanzapine pamoate. A literature search on PubMed/Medline up to 2011 was conducted by some doctors from London and found 30 cases of priapism associated with risperidone. Based on this work, we searched PubMed through 2021, using the keywords 'priapism' and 'risperidone' and found a total of 43 cases of priapism involving risperidone. Priapism is not correlated with the dosage of this psychotropic drug, and has also occasionally occurred when risperidone has been used in conjunction with another drug. The question of choosing a replacement antipsychotic after the first one has induced priapism, remains problematic. It would be preferable to switch to a drug with less marked alpha1-blocking properties, but no consensus has been reached as to the best choice of medication. Finally, any prescription of an antipsychotic treatment must be preceded by a careful interrogation in search of risk factors for priapism, and the patient should be made aware of the possible occurrence of this side effect and the need to then seek urgent medical advice.

Priapism induced by various psychotropics: A case series

Objective: Priapism is a rare adverse effect of several psychotropics. Both, typical and atypical antipsychotics, as well as trazodone are known to cause priapism. The mechanism is still not fully understood, however, the most common assumption is that priapism occurs due to the α-adrenergic blocking effects of the drugs. Methods: Here we present from the AMSP database 19 cases of priapism being likely caused by a variety of psychotropics. We further reviewed case reports in order to find similarities and to identify risk factors. Results: Several patterns emerged: common was the introduction of a specific drug to a patient resulting into the immediate development of priapism, as well as a change in drug plasma concentration due to a change of drug dosage or due to comedication with certain SSRIs. Conclusion: However, priapism can occur at nearly any age and with any dose. Clinicians must be aware of the risk and reports of early signs, such as prolonged erections, should be taken seriously.

Priapism associated with risperidone: a case report, literature review and review of the South London and Maudsley hospital patients' database

Priapism is a urological emergency defined as persistent penile erection that is unrelated to sexual stimulation and typically involving only the corporal cavernosa. It can occur as a rare side effect of antipsychotic medications and is mediated via their α-adrenergic antagonist effect. In this paper we describe a case of priapism in a patient started on risperidone and sodium valproate. We also review the South London and Maudsley Case Register Interactive Search 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.

Priapism in antipsychotic drug use: a rare but important side effect

Priapism is a rare but important side effect of antipsychotic drugs which may evolve into a urological emergency. Most antipsychotic drugs are alpha-1 adrenergic antagonists, which is thought to be the principal mechanism involved in antipsychotic-induced priapism. Other aetiologies exist, however. A case is presented with multiple episodes of priapism during the use of several different antipsychotic drugs. The case is representative of many patients treated with antipsychotic drugs, as there were hyperprolactinemia, and illicit drug use, which are known causes of priapism. Moreover, the patient used combinations of antipsychotic drugs. The case thus illustrates the etiological complexity which could delay a diagnosis of antipsychotic-induced priapism, and the problem of establishing a link between priapism and one particular ingredient of a drug combination. The case presents how a treatment regimen was finally established balancing antipsychotic efficacy to acceptable side effects and offers guidance to physicians regarding how antipsychotic-induced priapism may be resolved.

Priapism and risperidone

A patient taking oral risperidone while using cocaine and alcohol presented with priapism shortly after long-acting, injectable risperidone was prescribed. Another case of priapism was diagnosed in a sickle cell disease patient who was on oral risperidone. A penectomy due to necrosis was required in the first case, while the other patient regained erectile function. Physicians should be aware of priapism-inducing/predisposing factors, such as sickle cell disease, certain medicines or drugs of abuse, and antipsychotic medications. Risperidone is an established cause of priapism. It occurs especially in males with sickle cell disease; use of antipsychotic drugs and/or cocaine further increases risk.

[Priapism associated with antipsychotic medications: a series of four patients]

INTRODUCTION

Ischemic (veno-occlusive, low flow) priapism is a painful and persistent penile erection unrelated to sexual desire or stimulation. In some cases, it is an adverse event of antipsychotic medications.

MATERIAL

Between 1st January 2000 and 30th September 2007, four men (range 25/55 years), treated with antipsychotic agents (amisulpride, clozapine, levomepromazine, olanzapine, pipotiazine, risperidone or zuclopenthixol), presented one or several episodes of ischemic priapism. No other etiological factor was diagnosed. The patients were treated with aspiration and irrigation of the corpa cavernosa with intracavernous injection of sympathomimetic drugs followed in one case by a surgical distal cavernoglanular shunt.

DISCUSSION

Many conventional or atypical antipsychotic agents have been reported to cause priapism. Drug-induced priapism comprised of about 30% of the cases and an estimated 50% of them occurred with antipsychotic agents. The mechanism of priapism associated with antipsychotics agents thought to be related to alpha-adrenergic blocking properties. The decision of whether to restart a patient on a specific antipsychotic agent after an episode of priapism is a difficult clinical decision. An agent with low peripheral alpha-adrenergic blocking affinity would be preferred.

CONCLUSION

Ischemic priapism is an urologic emergency. Clinicians should be familiar with this rare but serious adverse event of antipsychotic agents to avoid long-term sequelae including erectile dysfunction.

Priapism associated with atypical antipsychotic medications: a review

Priapism defined as persistent, painful and prolonged penile erection, was previously thought to be associated only with the use of the older, conventional first generation or typical antipsychotic medications as well as some other medications, notably, trazodone. The mechanism of priapism associated with antipsychotics is not clear but is thought to be related to alpha-adrenergic blockage that is mediated by the alpha receptors in the corpora cavernosa of the penis. Atypical antipsychotics, also known as second-generation antipsychotics, owing to their favorable side effect profile, are being prescribed with increasing frequency and are not as frequently considered to cause priapism. Some case reports reporting this side effect with their use, however, are found. Pubmed and Ovid databases were searched to obtain all articles and case reports of antipsychotic drug-induced priapism. Key search words included 'priapism', 'antipsychotics' and 'drug-induced priapism'. References of all identified studies were also reviewed. A total of 50 publications were obtained. Most of the atypical antipsychotics have been reported to cause priapism. These cases have occurred in patients shortly after having been started on the antipsychotic medications as well as in those who have been on them for an extended period of time without modification in dosage, and have also occurred sometimes, with the addition of another antipsychotic, lithium or serotonin-specific reuptake inhibitor. Priapism has been documented with nearly all the atypical antipsychotic medications. It is, however, a rarely reported side effect and therefore, underappreciated. Priapism can cause irreversible erectile dysfunction and is a urologic emergency. Clinicians should monitor patients on these medications for this rare, yet significant side effect. Furthermore, caution must be used when adding new drugs to the regimen and patients should be closely monitored for this side effect. Educating patients about the risk of developing priapism would help increase awareness of the side effect and promote early reporting thereby, decreasing long-term morbidity.