Priapism associated with atypical antipsychotic medications: a review

Abstract

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.

Quetiapine-induced priapism

“…Another issue is that priapism can occur at any time of the medication, at the beginning or sometime later, thus, duration or treatment dose of medication is not found to be associated [8].…”

Genital Somatic Complaints in a Woman with Schizoaffective Disorder

“…Substances associated with priapism include antidepressants (paroxetine, fluoxetine, 2,6,7 bupropion, 7 nefazodone, trazodone), 3 antipsychotics (chlorpromazine, olanzapine, risperidone), 3 anabolic steroids, 9 and cocaine. 3 The patient in this case had no history of cocaine use or trazodone overdose.…”

“…Some authors recognize the utility of using alpha agonists, such as phenylephrine or pseudoephedrine. 1,3,4,7 A case report by Arntzen and de Boer 4 used an injection of 0.5 mL of 1:100,000 epinephrine solution and 0.5 mL of 500 U/mL of heparin with successful results. Nonsteroidal anti-inflammatory drugs and ice are additional options for pain relief.…”

“…2 One proposed idea is that improved circulation of the corpora cavernosa leads to increased pressure in the clitoral area. 3,4 Corpora blood outflow is linked to alpha blockade. The use of alpha-blocking agents, such as trazodone, can cause smooth muscle relaxation and stasis, leading to prolonged erection.…”

Current Perspectives on Pharmacotherapy Treatments for Erectile Dysfunction

“…Trazodone has alpha-adrenergic blocking effects (α-AR) and, together with its metachlorophenylpiperazine (m-CCP) metabolite, trazodone is known to induce erections in animal studies by selectively blocking the α-AR receptors and by increasing the spontaneous firing rate of cavernosal tissue nerves [31]. Despite its promising mode of actions within the cavernosum tissue, trazodone is not an effective treatment for most men with ED, since orally administered trazodone has been associated with high frequencies of priapism [32]. Furthermore, in a double-blind, placebo trial trazodone was not effective even at high doses of 150 to 200 mg per day [30,[33][34].…”