What medications are associated with priapism?

Medications Associated with Priapism

Multiple medication classes can cause priapism, including antipsychotics, antidepressants, antihypertensives, anticoagulants, and vasoactive agents used for erectile dysfunction treatment. 1 Priapism is a urological emergency that requires prompt recognition and treatment to prevent permanent erectile dysfunction.

Common Medication Classes Associated with Priapism

Antipsychotics

• Approximately 50% of drug-related priapism cases are attributed to antipsychotic medications 2
• Both typical and atypical antipsychotics can cause priapism through α1-adrenergic blockade in the corpora cavernosa 2, 3
• Risk appears related to the medication's α1-adrenergic receptor affinity
• Among conventional antipsychotics, chlorpromazine and thioridazine have the highest α1-adrenergic affinity and most frequently reported association with priapism 3
• Atypical antipsychotics including risperidone, olanzapine, and clozapine have been reported to cause priapism 3

Antidepressants

• Several antidepressant classes are implicated:
  • Selective Serotonin Reuptake Inhibitors (SSRIs): paroxetine, sertraline, fluoxetine, citalopram 1
  • Tricyclic antidepressants: clomipramine 1
  • Other antidepressants: trazodone (particularly high risk) 4, 5
• Trazodone carries a specific warning in its FDA label regarding priapism risk 4
• Sertraline and other SSRIs list priapism as a rare adverse event 6

Vasoactive Agents for Erectile Dysfunction

• Intracavernous injection therapy agents: alprostadil, papaverine, prostaglandin E1, phentolamine 1
• PDE5 inhibitors like sildenafil carry warnings about priapism risk, particularly in patients with anatomical deformation of the penis or conditions predisposing to priapism 7

Other Medications

• Antihypertensives 1
• Anticoagulants 1
• Recreational substances: alcohol, marijuana, cocaine 1, 8

Risk Factors and Mechanisms

Mechanism of Medication-Induced Priapism

• Most commonly caused by α1-adrenergic blockade in the corpora cavernosa, which inhibits normal detumescence 2, 3
• Medications with higher α1-adrenergic affinity pose greater risk
• Individual susceptibility varies significantly, suggesting additional risk factors 2

Patient Risk Factors

• History of previous episodes of priapism or prolonged erections 2
• Underlying conditions:
  • Sickle cell disease
  • Multiple myeloma
  • Leukemia
  • Anatomical deformation of the penis (angulation, cavernosal fibrosis, Peyronie's disease) 4, 7

Clinical Considerations

Timing of Priapism Development

• Can occur shortly after starting medication
• May develop after long-term stable use without dosage changes
• Can be triggered when adding another medication to the regimen 5

Warning Signs and Patient Education

• Patients taking high-risk medications should be educated about:
  • Signs and symptoms of priapism
  • The need to seek immediate medical attention for erections lasting >4 hours 4, 7
  • Potential consequences of delayed treatment (irreversible erectile dysfunction)

Management Approach

Immediate Actions

• Discontinue the suspected causative medication
• Urological emergency referral for erections lasting >4 hours
• Standard management of ischemic priapism includes:
  • Intracavernous injection of an alpha-adrenergic sympathomimetic agent
  • Aspiration/irrigation of the corpora cavernosa
  • Surgical shunting procedures if necessary 1

Medication Switching Considerations

• For patients requiring continued treatment with psychotropic medications:
  • Consider agents with lower α1-adrenergic affinity
  • Amisulpride has been suggested as an alternative antipsychotic with minimal α1-adrenergic affinity 9
  • Monitor closely when initiating any new medication

Prevention of Recurrence

• For patients with recurrent ischemic priapism, preventative strategies may include:
  • PDE5 inhibitors (tadalafil or sildenafil) on a regimented schedule
  • Ketoconazole with prednisone (with liver function monitoring)
  • Pseudoephedrine
  • Cyproterone acetate (not available in US) 1

Important Cautions

• Priapism is a urological emergency requiring immediate attention
• Delay in treatment beyond 4-6 hours can lead to permanent erectile dysfunction
• Patients with sickle cell disease require concurrent management of both the priapism and the underlying condition 1
• Hormonal treatments for recurrent priapism may impair fertility and sexual function 1