Priapism associated with antipsychotics: role of alpha1 adrenoceptor affinity

The atypical antipsychotics and sexual dysfunction: a pharmacovigilance-pharmacodynamic study

Background

Atypical antipsychotics (AAPs)-induced sexual dysfunction (SD) is a frequent issue in clinical practice, often underestimated by clinicians and not extensively researched. The current study aimed to quantify the strength of association between the use of different AAPs and SD using real-world data from the FDA Adverse Event Reporting System (FAERS), as well as investigate the receptor mechanisms that are involved.

Methods

Data from the FAERS database from the first quarter of 2004 to the third quarter of 2023 were queried through OpenVigil 2.1. Disproportionality analysis was estimated using the reporting odds ratio (ROR) and information component (IC) methods, and linear regression was used to investigate the relationship between ROR and receptor occupancy which was estimated using in vitro receptor binding profiles.

Results

Our analysis yielded 4839 reports that co-mentioned AAP and SD events, and the findings revealed statistical associations between 12 AAPs and SD. The highest signal value was identified for iloperidone reporting retrograde ejaculation with iloperidone (ROR = 832.09, ROR025 = 552.77; IC = 9.58, IC025 = 6.36), followed by compulsive sexual behavior with aripiprazole (ROR = 533.02, ROR025 = 435.90; IC = 7.30, IC025 = 5.97), and psychosexual disorder for aripiprazole (ROR = 145.80, ROR025 = 109.57; IC025 = 6.47, IC025 = 4.86). Different characteristics of the SD side effects in each AAPs were discovered after further data mining. Regression analysis revealed potential effects for receptor occupancy of D2, D3, and 5-HT1A receptors on ROR. However, no significant correlation persisted following sensitivity analyses.

Conclusion

This is the first study to investigate the AAP-SD associations by using FAERS. In this study, we report for the first time a significant association between aripiprazole and SD based on real-world data. The study suggests that different AAPs have varying levels of association with SD, and the D2, D3, and 5-HT1A receptor occupancy may contribute to potential mechanisms. The findings of this study warrant further validation of more studies and clinical causality assessment.

Priapism caused by partial deficiency of tetrahydrobiopterin through hypofunction of the sympathetic neurons in sepiapterin reductase gene-disrupted mice

6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor for aromatic L-amino acid hydroxylases, including tyrosine hydroxylase (TH), alkylglycerol monooxygenase, and three types of nitric oxide (NO) synthases (NOS). Sepiapterin reductase (SPR) catalyzes the third step of BH4 biosynthesis. SPR gene-disrupted (Spr-/- ) mice exhibit a dystonic posture, low body weight, hyperphenylalaninemia, and unstable hypertension with endothelial dysfunction. In this study, we found that Spr-/- mice suffered from a high incidence of severe priapism. Their erections persisted for months. The biopterin, BH4, and norepinephrine contents, and TH protein levels in the penile tissue of Spr-/- mice without and with priapism were significantly reduced compared to those of Spr+/+ mice. In contrast, their neural NOS (nNOS) protein levels were increased, and the cyclic guanosine monophosphate (cGMP) levels were remarkably elevated in the penises of Spr-/- mice with priapism. The symptoms were relieved by repeated administration of BH4. The biopterin, BH4, and norepinephrine contents were increased in penile homogenates from BH4-supplemented Spr-/- mice, and the TH protein levels tended to increase, and their nitrite plus nitrate levels were significantly lower than those of vehicle-treated Spr-/- mice and were approximately the same as vehicle- and BH4-supplemented Spr+/+ mice. Thus, we deduced that the priapism of Spr-/- mice is primarily caused by hypofunction of the sympathetic neurons due to cofactor depletion and the loss of TH protein and, further, dysregulation of the NO/cGMP signaling pathway, which would be caused by disinhibition of nNOS-containing neurons and/or abnormal catabolism of cyclic nucleotides is suggested.

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.

Loxapine-Induced Priapism: A Case Report and Review of the Literature on Antipsychotic-Induced Priapism

In this case report, a patient with schizophrenia experienced recurrent priapism while undergoing treatment of acute psychosis. This necessitated a review of the emergent treatment of priapism and discussion of the difficulties in treating priapism in a patient with acute psychosis. Therefore, this case report explores multiple possible etiologies of priapism within the realm of psychiatric care, reviews the proposed mechanisms of medication-induced priapism, and considers the psychopharmacological concepts that pertain to antipsychotic selection in the context of antipsychotic-induced priapism.

Recurrent Priapism From Cabergoline and Bromocriptine in a Hypogonadal Man With Prolactinoma

Dopamine agonists are generally well tolerated and represent the first-line therapy for prolactinomas. We report a case of a 20-year-old man with a macroprolactinoma who developed recurrent priapism with cabergoline and bromocriptine. Transsphenoidal pituitary adenoma resection was done with normalization of the prolactin level. Priapism is a rare side effect of dopamine agonists that warrants discontinuation of therapy. Patients should be educated about this potential side effect at the time of prescribing the medication.

Safety of antipsychotic drugs: A systematic review of disproportionality analysis studies

Antipsychotic drugs are commonly prescribed, mainly for the treatment of schizophrenia and other psychotic disorders. Disproportionality analysis of pharmacovigilance data from national and international databases have been recently utilized to investigate the side-effect profiles of antipsychotics and have provided unique insights of their safety. Among several national and international spontaneous reporting databases the databases of the World Health Organization (VigiBase), of the European Medicines Agency (EudraVigilance) and the US Food and Drug Administration (FAERS) incorporate millions of Individual Case Safety Reports. The aim of our study was to systematically review published disproportionality analyses on antipsychotic drugs, in order to summarize the current state of methodology and potential strengths of this analysis while highlighting safety signal generated for these pharmacological group. PubMed was searched using a search algorithm combining terms for antipsychotic drugs and disproportionality analysis. A total of 39 articles were found to be eligible corresponding to 38 original disproportionality studies. Different measures of disproportionality were used in each study: reporting odds ratio (ROR), proportional reporting ratio (PRR), empirical Bayes geometric mean (EBGM) and the information component (IC). Despite the inherent limitations of the pharmacovigilance databases disproportionality analysis provides complemented evidence from RCTs on the safety of antipsychotics, especially regarding participants often excluded from RCTs, such as pregnant and breastfeeding women, children and participants with drug abuse, comorbidities or concomitant medications.

A very rare case of priapism under aripiprazole in a patient followed for bipolar disorder: A CARE-compliant report

INTRODUCTION AND IMPORTANCE

Priapism is a urological emergency characterized by abnormally prolonged, painful and irreducible erection. It occurs without a sexual stimulation and habitually exceeds 6 h. About a half of iatrogenic priapisms are believed to be associated with antipsychotics. Until to date, very few cases of aripiprazole-associated priapism were reported.

CASE PRESENTATION

In this case report, we present the clinical findings of a 40-year-old patient that developed priapism after treatment with aripiprazole after his hospitalization for an episode of clinical mania following treatment discontinuation for bipolar I disorder. The management was successful and priapism was resolved spontaneously.

CLINICAL DISCUSSION

Despite its low affinity to alpha-1 adrenergic receptors, aripiprazole may be associated with priapism. Several potential factors involved in the pathogenesis of this adverse event have been reported in the literature including history of priapism in a different class of neuroleptics and consumption of psychoactive drugs which are the principal factors found in our case.

CONCLUSION

Priapism may occur even during treatment with antipsychotics that have a low affinity to alpha1-adrenergic receptors. All patients on antipsychotics should be informed about the risk of this rare but serious adverse event.

A Review of Antipsychotics and Priapism

INTRODUCTION

Pharmacologically induced priapism is now the most common cause of priapism, with approximately 50% of drug-related priapism being attributed to antipsychotic usage. The majority of pharmacologic priapism is believed to result in ischemic priapism (low flow), which may lead to irreversible complications, such as erectile dysfunction. It is imperative that prescribing physicians be aware of potentially inciting medications.

OBJECTIVES

To identify medications, specifically antipsychotics, associated with priapism and prolonged erections and understand the rates and treatment of these side effects.

METHODS

A PubMed search of all articles available on the database relating to priapism, prolonged erections, and antipsychotics was performed.

RESULTS

Various typical and atypical antipsychotic drugs (APDs) have been implicated in pharmacologically induced priapism. In addition to dopaminergic and serotoninergic receptors, APDs have affinities for a wide array of other receptors in the central nervous system, including histaminergic, noradrenergic, and cholinergic receptors. Although the exact mechanism is unknown, the most commonly proposed mechanism of priapism associated with APDs is α-adrenergic blockade in the corpora cavernosa of the penis. Priapism appears in only a small fraction of men using medications with α1-receptor-blocking properties, indicating differential sensitivities to the α-blocking effect among men, and/or additional risk factors that may contribute to the development of priapism. The best predictor for the subsequent development of priapism is a past history of having prolonged and painless erections. The acute management algorithm of APD-induced priapism is the same as for other causes of low-flow priapism.

CONCLUSION

Clinicians should educate patients treated with antipsychotics about the potential for priapism and its sequelae including permanent erectile dysfunction. Appropriate patient education will raise awareness, encourage early reporting, and help reduce the long-term consequences associated with priapism through early intervention. Hwang T, Shah T,Sadeghi-NejadH. A Review of Antipsychotics and Priapism. Sex Med Rev 2021;9:464-471.

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.

Intractable acute ischaemic priapism occurring secondary to newly commenced olanzapine

We present a case of intractable acute ischaemic priapism occurring secondary to newly commenced olanzapine. It demonstrates rapid intervention in a stepwise approach aiming to restore penile flaccidity in order to prevent chronic damage to the corpora cavernosa. After an unsuccessful conservative approach, our patient underwent two formal distal penile shunt procedures with no effective penile detumescence. Subsequently, bilateral proximal penile shunts were performed comprising a right corpus cavernosum to corpus spongiosum anastomosis and a left saphenous vein to left corpus cavernosum anastomosis. The patient remained an inpatient for observation, and detumescence was gradually achieved over several days after this procedure. However, follow-up revealed erectile dysfunction, and it was explained to the patient that he was unlikely to achieve further erections and that a penile implant was the only realistic option.

Detecting and Managing Adverse Effects of Antipsychotic Medications: Current State of Play

Antipsychotics are some of the most frequently prescribed medications not only for psychotic disorders and symptoms but also for a wide range of on-label and off-label indications. Because second-generation antipsychotics have largely replaced first-generation antipsychotics as first-line options due to their substantially decreased risk of extrapyramidal side effects, attention has shifted to other clinically concerning adverse events associated with antipsychotic therapy. The focus of this article is to update the nonextrapyramidal side effects associated with second-generation antipsychotics. Issues surrounding diagnosis and monitoring as well as clinical management are addressed.

Aripiprazole-induced priapism

Priapism is a urologic emergency representing a true disorder of penile erection that persists beyond or is unrelated to sexual interest or stimulation. A variety of psychotropic drugs are known to produce priapism, albeit rarely, through their antagonistic action on alpha-1 adrenergic receptors. We report such a case of priapism induced by a single oral dose of 10 mg aripiprazole, a drug with the least affinity to adrenergic receptors among all atypical antipsychotics. Polymorphism of alpha-2A adrenergic receptor gene in schizophrenia patients is known to be associated with sialorrhea while on clozapine treatment. Probably, similar polymorphism of alpha-1 adrenergic receptor gene could contribute to its altered sensitivity and resultant priapism. In future, pharmacogenomics-based approach may help in personalizing the treatment and effectively prevent the emergence of such side effects.

Risperidone, quetiapine and chlorpromazine may have induced priapism in an adolescent

Priapism is the prolonged, painful erection of penile tissue not accompanied by sexual arousal. Priapism has been established as a rare adverse drug reaction to drugs such as antipsychotics, psychostimulants, antidepressants, and mood stabilizers. Immediate intervention is needed to prevent destructive and irreversible complications, such as erectile dysfunction, disfigurement, inability of the penis to stay erect, and related social/emotional problems. Antipsychotic-induced priapism may result from the alpha receptor occupancy property of those drugs. We report the case of a 13-year-old suffering from attention deficit-hyperactivity disorder plus conduct disorder with priapism related to antipsychotics. Episodes occurred with risperidone plus methylphenidate, quetiapine plus methylphenidate, and chlorpromazine alone.

Recurrent priapism from therapeutic quetiapine

Priapism is rarely related to use of non-erectile related medications. The objective was to educate about the multiple possible causes of priapism and to provide treatment recommendations for the different types of priapism. We present the case of a 43-year-old African American male with a history of schizoaffective disorder who presented to our emergency department multiple times over a three year period with priapism, each episode related to the ingestion of quetiapine. Following penile aspiration and intercavernosal injection of phenylephrine, this patient had resolution of his priapism. This case demonstrates an unusual case of recurrent priapism.

Paliperidone Palmitate for Schizoaffective Disorder: A Review of the Clinical Evidence

INTRODUCTION

Despite being frequently diagnosed, there has been very limited study of efficacious treatments for schizoaffective disorder. Paliperidone had been approved for the treatment of schizoaffective disorder, and a recently completed relapse prevention study of the use of a once-monthly injectable paliperidone formulation has also led to an indication for that preparation to treat schizoaffective disorder.

METHODS

To review the efficacy and tolerability of paliperidone for schizoaffective disorder, we conducted a systematic literature search of studies of paliperidone in the treatment of schizoaffective disorder, and briefly reviewed evidence regarding the somewhat controversial nature of that diagnostic entity.

RESULTS

We located several studies of the use of paliperidone extended release in the treatment of schizoaffective disorder, but only one completed study of the use of paliperidone palmitate, which demonstrated efficacy in preventing relapse. Three other studies are currently recruiting participants. Efficacy and tolerability were similar to the profile of oral paliperidone in the treatment of individuals with schizophrenia. These results were similar for both individuals treated with paliperidone palmitate alone, and for those treated with paliperidone palmitate with adjunctive mood stabilizers and/or antidepressants. The use of paliperidone palmitate does not require initial co-administration of oral paliperidone, has relatively little risk of drug-drug interactions, and its pharmacokinetics are favorable for once-monthly administration, an important treatment option for individuals with psychotic disorders, who may often be non-adherent to effective medication regimens.

CONCLUSION

Paliperidone palmitate is an approved treatment for schizoaffective disorder, and can be efficacious with or without commonly employed adjunctive treatments.

Priapism and clozapine use in a patient with hypochondriacal delusional syndrome

Priapism is a urological emergency that results in a penile or clitoral engorgement, having several triggers by the use of medications, including psychiatric drugs, such as antipsychotics and antidepressants. The most common priapism presentation is the ischemic type that can result in the fibrosis of corporus cavernosus, with a significant risk of persistent erectile dysfunction. It is believed that, in the case of antipsychotic use, priapism is mediated by an imbalance in alpha-1-adrenergic blocking, with large variation affinity for alpha-1-adrenergic receptors among antipsychotics. This case report contributes to the study of this rare but severe side effect. Priapism can limit both treatment adherence and the reproductive future of our patients. We describe a case report of a patient with a delusional hypochondriac syndrome who had multiple priapism episodes using clozapine 50 mg/daily. In conclusion, we make brief comments on priapism management, a hard clinical dilemma.

The influence of atypical antipsychotic drugs on sexual function

Human sexuality is contingent upon many biological and psychological factors. Such factors include sexual drive (libido), physiological arousal (lubrication/erection), orgasm, and ejaculation, as well as maintaining normal menstrual cycle. The assessment of sexual dysfunction can be difficult due to the intimate nature of the problem and patients' unwillingness to discuss it. Also, the problem of dysfunction is often overlooked by doctors. Atypical antipsychotic treatment is a key component of mental disorders' treatment algorithms recommended by the National Institute of Health and Clinical Excellence, the American Psychiatric Association, and the British Society for Psychopharmacology. The relationship between atypical antipsychotic drugs and sexual dysfunction is mediated in part by antipsychotic blockade of pituitary dopamine D2 receptors increasing prolactin secretion, although direct correlations have not been established between raised prolactin levels and clinical symptoms. Variety of mechanisms are likely to contribute to antipsychotic-related sexual dysfunction, including hyperprolactinemia, sedation, and antagonism of a number of neurotransmitter receptors (α-adrenergic, dopaminergic, histaminic, and muscarinic). Maintaining normal sexual function in people treated for mental disorders can affect their quality of life, mood, self-esteem, attitude toward taking medication, and compliance during therapy.

A case of priapism with risperidone

Priapism is a urologic emergency defined as a prolonged, possibly painful, penile erection. There are several known causes of priapism including psychotropic medications. One of the mechanisms by which antipsychotics are believed to induce priapism is through alpha-1 antagonism. This is case of a 50-year-old male with a history of schizophrenia with previous priapism related to trazodone, who presents with new onset priapism associated with risperidone. In this case, the treatment of priapism includes discontinuation of the offending agent and drainage of the corpus cavernosum twice along with intracavernosal phenylephrine injections. It is important to educate patients on priapism as a possible side effect of medications. It is also important to consider previous episodes of medication-induced priapism when prescribing psychotropic medications as this may increase the patient's future risk of priapism.

Priapism associated with iloperidone: a case report

Priapism is a known side effect of antipsychotics. The causal mechanism seems to be mediated through α1-adrenergic receptor blockade which many antipsychotics are known to possess. We present the first detailed case of iloperidone-induced priapism in a patient with bipolar disorder with psychotic features. His case highlights some of the important risk factors clinicians should consider when using iloperidone, as it may be the highest-risk antipsychotic for causing priapism given it is a very potent blocker of the alpha-adrenergic receptor.

[Antipsychotic-induced priapism and management challenges: a case report]

INTRODUCTION

Priapism is a persistent, and often painful, penile erection, lasting more than 3 hours, not usually associated with sexual stimuli. It is a urological emergency that can cause serious complications. Drugs are responsible of the onset of 25 to 40% of cases of priapism. Several classes of medication are involved: antidepressants, antihypertensives, anticoagulants, alpha-blockers and some psychoactive substances (alcohol, cocaine, cannabis...). However, about 50% of drug related priapism is due to antipsychotics (AP). Clinicians should be aware of this rare side effect because of the severity of its complications and the difficulty of its management, especially in non-stabilized psychotic patients.

CASE REPORT

We report a case of a 22-year-old male Moroccan patient, diagnosed with schizophrenia, who had been admitted for the first time to a psychiatric hospital for management of a psychotic episode. First, he received 15 mg per day of haloperidol, and seven days later he developed priapism. The patient was immediately referred for urological care. Aspiration and irrigation of the corpora cavernosa was proposed, but could not be performed because of patient refusal, and the erection resolved spontaneously after 10 hours. Haloperidol was stopped, and four days later the patient was switched to 10mg per day of olanzapine. After 10 days of treatment, he developed a second episode of priapism, and olanzapine was also stopped. A cavernosal aspiration-irrigation was performed in emergency; which resulted in the partial detumescence of the penis. Two days later, and despite therapeutic abstention, the patient presented another episode of priapism. The indication of a revascularization of the corpora cavernosa was proposed, but again the patient refused the surgery. Finally, the patient was administered 400mg/day of amisulpride, with a favorable outcome. Priapism disappeared after a month with the installation of fibrosis and partial loss of erectile function.

DISCUSSION

The precise mechanisms of the role of AP in the occurrence of priapism are not all known and a multifactor etiology seems the most likely. Neuromuscular hypothesis is the most mentioned, involving the blocking action of alpha1-adrenergic receptors of the corpora cavernosa for which most of AP have an affinity. The occurrence of priapism in a psychotic patient, especially during periods of decompensation, raises a number of challenges for the medical staff. First, the non-recognition by the patient of this side effect, and its potentially severe consequences. Second, the absence of link between dose and duration of AP treatment on one side, and the onset of priapism on the other, which makes it hard to predict. The third challenge is the choice and initiation of another AP. The literature reveals many cases of priapism in both conventional and atypical AP, the presence of a predisposition to this type of incident has been reported. However, few authors have focused on alternatives to provide for these patients. Amisulpride is currently the only molecule that does not have alpha-adrenergic affinity and is therefore preferred in these cases.

CONCLUSION

Priapism is a rare but serious adverse event of AP medication. Informing patient about the risk of priapism would help to report it early and prevent erectile dysfunction. Switching to another AP with less alpha1-blocking properties is generally recommended.

A case report of priapism caused by ziprasidon

Priapism is defined as having prolonged (more than 6 h), and usually painful penile erection that occurs without a sexual desire or arousal. Only a very few priapism cases caused by ziprasidone are reported in the literature. In this case report we aimed to present a prolonged penile erection due to use of ziprasidone.

Priapism induced by boceprevir-CYP3A4 inhibition and α-adrenergic blockade: case report

A 44-year-old white man presented to the emergency department with a 3-day history of priapism requiring a surgically performed distal penile shunt. A drug-drug interaction is the suspected cause whereby CYP3A4 inhibition by boceprevir led to increased exposures of doxazosin, tamsulosin, and/or quetiapine, resulting in additional α-adrenergic blockade.

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: comorbid factors and treatment outcomes in a contemporary series

Objective. The goal of this study is to describe comorbid characteristics in patients who have priapism, and their treatment outcomes. Methods. Chart review was undertaken on men who had a diagnosis of priapism from a tertiary medical center, from 2000-2010. Men with priapism due exclusively to the use of prescription erectile aids and medications were not included in the review. Results. We identified 79 patients with the priapism. The most common type of priapism was the low flow variant. High flow priapism was identified in 2 patients. The most common general comorbid condition associated with priapism was mental illness (including substance abuse), which was present in 56% of the patients. Neurogenic priapism accounted for 19% of the total priapism events. Psychopharmaceutical agents and recreational drugs were commonly associated with ischemic priapism. Acute complications of priapism treatment were not common, but long-term complications, especially erectile dysfunction, were frequent. Conclusions. We describe the characteristics and outcomes of a large group of patients with priapism. Our experience at a tertiary care center indicates that mental illness, including substance abuse disorders, is a highly prevalent comorbid condition in men who experience priapism. Consistent with previous reports, erectile dysfunction is the most common complication from priapism and its treatment, occurring in the majority of men.

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.

Drug safety evaluation of ziprasidone

INTRODUCTION

Ziprasidone is a second-generation antipsychotic approved for the treatment of schizophrenia and bipolar disorder. The purpose of this review is to assess the overall safety profile of ziprasidone, including its risk for prolonging the electrocardiogram (ECG) QT interval.

AREAS COVERED

This paper is a review of product labeling and English language reports located through PubMed and information available on regulatory agency websites, with a focus on the safety and tolerability of ziprasidone.

EXPERT OPINION

Although ziprasidone can prolong the ECG QT interval, this has not resulted in increases in sudden death or cardiac sudden death as noted in a large, simple trial and supported by almost a decade of real-world use in the US. Ziprasidone's principal advantage over some other second-generation antipsychotics has been its overall favorable weight and metabolic profile. Similar to most second-generation antipsychotics, ziprasidone has a lower propensity for extrapyramidal side effects and hyperprolactinemia compared to first-generation antipsychotics.