Showing posts with label Men's Health. Show all posts
Showing posts with label Men's Health. Show all posts

Wednesday, March 23, 2011

Clinical Aspects of Priapism

Introduction


Priapism is defined as an abnormal persistent erection of the penis. It is an involuntary prolonged erection unrelated to sexual stimulation and unrelieved by ejaculation. As with many medical emergencies, the saying "time is tissue" holds true for priapism. This condition is a true urologic emergency, and early intervention allows the best chance for functional recovery.

Pathophysiology

Priapism is the result of persistent engorgement of the corpora cavernosa of the penis, originating from a disturbance in the mechanisms that control normal penile detumescence, depicted in the image below. In most cases, the ventral corpora spongiosum and glans penis remain flaccid.


Two types of priapism are generally described.
           ^Arterial high-flow priapism usually is secondary to a rupture of a cavernous artery and unregulated flow into the lacunar spaces. This rare type of priapism is usually not painful and results from penetrating penile trauma or a blunt perineal injury.
           ^Low-flow priapism is usually due to full and unremitting corporeal veno-occlusion where venous stasis and deoxygenated blood pools within the cavernous tissue. Prolonged veno-occlusive priapism results in fibrosis of the penis and a loss of the ability to achieve an erection. Significant changes at the cellular level are noted within 24 hours in veno-occlusive priapism, whereas arterial priapism is not associated with fibrotic change.


Frequency


United States

In one study, 38-42% of adult patients with sickle cell disease reported at least one episode of priapism.
 International
The overall incidence of priapism is 1.5 cases per 100,000 person-years, which increases to 2.9 cases per 100,000 person-years for men older than 40 years.

Mortality/Morbidity


  • Priapism is painful at onset. Corporeal fibrosis due to persistent priapism can result in deep-tissue infections of the penis.
  • The major chronic morbidity associated with all types of priapism is persistent erectile dysfunction and impotence.
  • The duration of symptoms is the most important factor affecting outcome. A recent Scandinavian study reported that 92% of patients with priapism for less than 24 hours remained potent, while only 22% of patients with priapism that lasted longer than 7 days remained potent.

Race

No racial predilection exists. Sickle cell disease, which predisposes to the development of priapism, occurs more frequently in the African American population.

Sex

Priapism is primarily a disease of males. Priapism of the clitoris has been reported but is extremely rare.

Age


  • Priapism has been described at nearly all ages, from infancy through old age. A bimodal distribution between 5 and 10 years in children and 20-50 years in adults is noted. 
  • Younger groups are more often associated with sickle cell disease, while older groups tend to be secondary to pharmacologic agents.

Clinical


History

Patients with priapism report a persistent erection. The symptoms depend on the type of priapism and the duration of engorgement.

  • Low-flow, ischemic-type priapism is generally painful, although the pain may disappear with prolonged priapism.
  • High-flow, nonischemic priapism is generally not painful. This type of priapism is associated with blunt or penetrating injury to the perineum. It may manifest in an episodic manner.
  • Aspects of history are as follows:  
    • Erection: Duration of longer than 4 hours is consistent with priapism.
    • Duration of pain
    • Similar prior episodes
    • Genitourinary (GU) trauma
    • Medical history (eg, sickle cell disease [SCD]): Onset occurs during sleep, when relative oxygenation decreases.
    • Medication and/or recreational drug use, especially the antidepressant trazodone, intracavernosal injections of prostaglandin E1 used to treat impotence, and illicit cocaine injection into the penis
    • History of malignancy (prostate cancer)
    • Penile prosthesis: The permanent erection that occurs with some penile prostheses may mimic priapism.
    • Recent urologic surgery
  • Aspects of history in high-flow priapism are as follows:
    • Not painful
    • May be sexually active
    • Straddle injury usually the initiating event
    • Chronic recurrent presentation
    • Generally not caused by medication
  • Aspects of history of low-flow priapism are as follows:
    • Painful
    • Inactive sexually and without desire
    • No history of trauma
    • Usually presents to emergency department (ED) within hours
    • Associated with substance abuse or vasoactive penile injections
    • Rarely caused by leukemia, fat embolism, acute spinal cord injury, or (extremely rare) cancer metastases to the corporeal bodies

Physical


  • Presence of priapism should be confirmed by the finding of an erect or semierect penis. The ventral glans and corpus spongiosum are rarely rigid.
  • Carefully examine for evidence of trauma or unreported injection sites to the genital region.
  • Examine the patient for evidence of an underlying condition that may predispose to priapism.
  • Piesis sign - Perineal compression with thumb in young children causes prompt detumescence in high-flow priapism.

Causes


  • Medications
    • Only rare case reports of selective cyclic guanosine monophosphate (cGMP) inhibitors such as sildenafil have been associated with priapism. In fact, several case reports suggest sildenafil as a means to treat priapism and may be able to prevent full-blown episodes from occurring in patients with sickle cell disease.
    • Some patients may use injectable medications to induce an erection. In these patients, excessive use may produce priapism. Examples of agents used to induce an erection include papaverine, phentolamine, and prostaglandin E1.
    • Many psychotropic medications such as chlorpromazine, trazodone, quetiapine, and thioridazine have been associated with priapism. The newer agents are not immune to this complication. Priapism has been described with citalopram, a selective serotonin reuptake inhibitor.
    • Rebound hypercoagulable states with anticoagulants such as heparin and warfarin have been associated. Hydralazine, metoclopramide, omeprazole, hydroxyzine, prazosin, tamoxifen, and androstenedione for athletic performance enhancement.
    • Cocaine, marijuana, and ethanol abuse - The complication has been described in patients using ecstasy.
  • Thromboembolic
    • Sickle cell disease and thalassemia
    • Leukemia and multiple myeloma
  • Trauma (pelvic, genital, or perineal)
  • Neoplastic (may be primary or metastatic)
  • Neurologic
  • Infection
    • Recent infection with Mycoplasma pneumoniae (Mechanism is thought to be a hypercoagulable state induced by the infection.)
    • Malaria
  • Other causes


Sources:
http://www.netdoctor.co.uk/sexandrelationships/priapism.htm
http://emedicine.medscape.com/article/777603-overview
http://emedicine.medscape.com/article/437237-overview


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Tuesday, September 28, 2010

Libido and Aphrodisiacs (II)

 II. Aphrodisiacs

=are any of various forms of stimulation thought to arouse sexual excitement. Aphrodisiacs may be classified in two principal groups:

  • (1) psycho-physiological (visual, tactile, olfactory, aural)
  • (2) internal (stemming from food, alcoholic drinks, drugs, love potions, medical preparations).
      Despite long-standing literary and popular interest in internal aphrodisiacs, almost no scientific studies of them have been made. Scientific research is limited to occasional tests of drugs or hormones for the cure of male impotence. Most writings on the subject are little more than unscientific compilations of traditional or folkloric material. Of the various foods to which aphrodisiac powers are traditionally attributed, fish, vegetables, and spices have been the most popular throughout history. In none of these foods, however, have any chemical agents been identified that could effect a direct physiological reaction upon the genitourinary tract, and it must be concluded that the reputation of various supposedly erotic foods is based not upon fact but upon folklore.
         It has been suggested that man’s universal attribution of libidinous effects to certain foods originated in the ancient belief in the therapeutic efficacy of signatures: if an object resembled the genitalia, it possessed, so it was reasoned, sexual powers. Thus the legendary aphrodisiac powers of ginseng root and powdered rhinoceros horn.
         With the exception of certain drugs such as alcohol or marijuana, which may lead to sexual excitation through disinhibition, modern medical science recognizes a very limited number of aphrodisiacs.

Testosterone

Libido is clearly linked to levels of sex hormones, particularly testosterone. When a reduced sex drive occurs in individuals with relatively low levels of testosterone (e.g., post-menopausal women or men over age 60 ) ,testosterone supplements will often increase libido. Approaches using a number of precursors intended to raise testosterone levels have been effective in older males, but have not fared well when tested on other groups.
Yohimbine
Yohimbine is the main alkaloid of Yohimbe. Yohimbe, but not Yohimbine, is often popularly referred to as a "weak MAO inhibitor" although no sources are cited for this. Pharmaceutical preparations of yohimbine do not indicate that the drug, which is approved in the US for treatment of impotence (under such brand names as Yocon,Yohimex, Aphrodyne and Viritab), is an MAO inhibitor. Its main action is as an alpha-adrenergic antagonist, by which yohimbine may increase genital blood-flow and both sexual sensitivity and excitation in some people. Preparations of yohimbe bark are available over-the-counter and should be used with caution. The unrefined yohimbe bark contains several active alkaloids besides yohimbine. Side effects can include rapid pulse, sweating, and anxiety reactions in susceptible people. Pharmaceutical preparations of yohimbine can also produce these side effects at higher doses, but are available in standardized doses which allow the patient to dose in a controlled fashion. Some patients report a cumulative pro-sexual effect using the drug over time.

Bremelanotide

Some compounds that activate the melanocortin receptors MC3-R and MC4-R in the brain are effective aphrodisiacs. One compound from this class, bremelanotide, formerly known as PT-141, is undergoing clinical trials for the treatment of sexual arousal disorder and erectile dysfunction. It is intended for both men and women. Preliminary results have proven the efficacy of this drug, however development was briefly suspended due to a side effect of increased blood pressure observed in a small number of trial subjects who administered the drug intra-nasally. On August 12, 2009, Palatin, the company developing the drug, announced positive results (none of the previous heightened blood pressure effects were observed) of a phase I clinical study where trial subjects were instead administered the drug subcutaneously. Palatin is concurrently developing a related compound they call PL-6983.

Melanotan II

Melanotan II, bremelanotide's precursor has been demonstrated to have aphrodisiac properties.
PEA
There is some debate in lay circles as to whether a chemical called phenylethylamine present in chocolate is an aphrodisiac. There is some evidence to support the theory that phenethylamine release in the brain may be involved in sexual attraction and arousal but this compound is quickly degraded by the enzyme MAO and so it is unlikely that any significant concentrations would reach the brain when phenethylamine is taken orally.

Crocin

As per a new study, Crocin has demonstrated the properties of an aphrodisiac in rats.This is supported by pilot tests that demonstrate the efficacy of Saffron as an aphrodisiac.

Alkyl nitrites

Alkyl nitrites, (poppers), have a long history of use as a sexual enhancement aid, going back about fifty years. According to the text "Isobutyl nitrite and Related Compounds", many researchers agree that the alkyl nitrite may be a true aphrodisiac in the sense of promoting and enhancing sexual response.

Other drugs

Stimulants affecting the dopamine system such as cocaine and amphetamines (e.g. methamphetamine, aka crystal meth) are frequently associated with hyperarousal and hypersexuality, though both may impair sexual functioning, particularly with long term use.
Some directly acting dopamine agonists may also cause increased libido, although they can also cause various side effects. Pramipexole is the only dopamine agonist used in medicine as an aphrodisiac, and is sometimes prescribed to counteract the decrease in libido associated with SSRI antidepressant drugs. The older dopamine agonist apomorphine has been used for the treatment of erectile dysfunction, but is of poor efficacy and has a tendency to cause nausea. Other dopamine agonists such as bromocriptine and cabergoline may also be associated with increased libido, as can the dopamine precursor L-Dopa, but this is often part of a spectrum of side effects which can include mood swings and problem gambling and so these drugs are not prescribed for this purpose.
The libido-enhancing effects of dopamine agonists prescribed for other purposes has led to the development of a number of more selective compounds such as flibanserin, ABT-670 and PF-219,061, which have been developed specifically for the treatment of sexual dysfunction disorders, although none of them have yet passed clinical trials.

Drugs not considered aphrodisiacs

     Some psychoactive substances such as alcohol, cannabis, methaqualone, GHB and MDMA can increase libido and sexual desire. However these drugs are not aphrodisiacs in the strict sense of the definition, as they do not consistently produce aphrodisiac effects as their main action. However, these drugs are sometimes used to increase sexual pleasure and to reduce sexual inhibition.
Anti-erectile dysfunction drugs, such as Viagra and Levitra, are not considered aphrodisiacs because they do not have any direct effect on the libido, although increased ability to attain an erection may be interpreted as increased sexual arousal by users of these drugs.


Aphrodisiac foods and herbs

Some natural items purported to be aphrodisiacs when ingested or applied to the body.

Some newly introduced exotic foods often acquire such a reputation, at least until they become more familiar; for example:
  • Asparagus In 19th-century France, bridegrooms were served three courses of the vegetable at their prenuptial dinner
  • Bananas The sap of the red banana is considered an aphrodisiac in Central America
  • Tomatoes (allegedly to the French term pomme d'amour as a misrendering of pomme de Maure)
  • Truffles
  • Strawberries


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