Cocaine and ephedrine-induced priapism: case reports and investigation of potential adrenergic mechanisms.
OBJECTIVE
To investigate the direct effect of ephedrine and cocaine on neurogenic contraction of penile trabecular smooth muscle. We also provide three case reports of patients who developed priapism secondary to using either cocaine or nonprescription weight loss formulations containing ephedrine. The use/abuse of cocaine has been associated with priapism. In addition, anecdotal evidence suggests that priapism may result from ephedrine use. However, the effects of cocaine and ephedrine on adrenergic regulation of cavernosal tissue and the potential role of sympathetic dysregulation in the development of priapism have not been studied.


METHODS
Isolated rabbit penile cavernosal tissue strips in organ bath preparations were subjected to electrical field stimulation (EFS) at varying frequencies (5 to 40 Hz) in the absence or presence of ephedrine (60 microg/mL) or cocaine (10 microM). Tissues were then subjected to EFS every 30 minutes for up to 20 hours.


RESULTS
Ephedrine and cocaine initially caused contractions in cavernosal tissue strips that persisted for several hours. EFS-induced contractions became attenuated over time in tissues treated with ephedrine or cocaine. Eventually, the contractile responses to EFS were not distinguishable from the basal tone, although the tissues remained responsive to exogenous phenylephrine.


CONCLUSIONS
Functional activation of alpha-adrenergic receptors on trabecular smooth muscle does not appear to be impaired with prolonged cocaine or ephedrine exposure. However, chronic use of cocaine or ephedrine may deplete norepinephrine from sympathetic nerve terminals, leading to priapism.
Munarriz
Ricardo
R
Department of Urology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
Hwang
Jonathan
J
Goldstein
Irwin
I
Traish
Abdulmaged M
AM
Kim
Noel N
NN
D000316:Adrenergic alpha-Agonists / Q000009:adverse effects*; D000328:Adult; D000818:Animals; D019440:Anti-Obesity Agents / Q000009:adverse effects*; D003042:Cocaine / Q000009:adverse effects*; D019970:Cocaine-Related Disorders / Q000209:etiology* / Q000503:physiopathology; D004338:Drug Combinations; D029790:Ephedra sinica / Q000009:adverse effects*; D004809:Ephedrine / Q000009:adverse effects*; D007172:Erectile Dysfunction / Q000139:chemically induced; D006801:Humans; D007511:Ischemia / Q000139:chemically induced; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D004366:Nonprescription Drugs / Q000009:adverse effects; D010413:Penis / Q000098:blood supply; D011317:Priapism / Q000139:chemically induced* / Q000503:physiopathology; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology
D000316:Adrenergic alpha-Agonists; D019440:Anti-Obesity Agents; D004338:Drug Combinations; D004366:Nonprescription Drugs; D011942:Receptors, Adrenergic, alpha; D004809:Ephedrine; D003042:Cocaine