Yohimbine vs Muira puama *
in the treatment of erectile dysfunction
The term "impotence" has traditionally been used to signify the inability of the male to attain and maintain erection of the penis sufficient to permit satisfactory sexual intercourse. Impotence, in most circumstances, is more precisely referred to as erectile dysfunction as this term differentiates itself from loss of libido, premature ejaculation, or inability to achieve orgasm.1
An estimated 10 to 20 million men suffer from erectile dysfunction. This number is expected to increase dramatically as the median age of the population increases. Currently, erectile dysfunction is thought to affect over 25% of men over the age of 50. 1,2
Although the frequency of erectile dysfunction increases with age, it must be stressed that aging itself is not a cause of impotence. Although the amount and force of the ejaculate as well as the need to ejaculate decrease withage, the capacity for erection is retained. Men are capable of retaining their sexual virility well into their 80's.
Erectile dysfunction may be due to organic or psychogenicfactors. In the overwhelming majority of cases the cause is organic, ie., it is due to some physiological reason. In fact, in men over the age of 50, organic causes are responsible for erectile dysfunction in over 90%.3 In the past, a man with impotence who was able to have nighttime or early morning erections was thought to have psychogenic impotence. However, it is now recognized that this is not a reliable indicator.2
Yohimbine
The only FDA approved medicine for impotence is yohimbine an alkaloid isolated from the bark of the yohimbe tree (pausinystalia johimbe) native to tropical West Africa. Yohimbine hydrochloride increases libido, but its primary action is to increase blood flow to erectile tissue. Yohimbine is a selective alpha-2 receptor antagonist Contrary to a popular misconception, yohimbine has no effects on testosterone levels.
When used alone, yohimbine is successful in 34% to 43% of cases. 4,5 It is effective in both psychogenic and organic causes of impotence. The standard close of yohimbine is 15 to 20 mg per day, however, higher doses, up to 42mg of yohimbine, may prove to be more effective.
To illustrate the benefits to be expected in clinical practice, let's examine the results from one of the more recent doubleblind studies. In the study, 82 men with erectile dysfunction selected from a Veterans Administration population with a high incidence of diabetes and vascular disease underwent a multifactorial evaluation, including determination of penile brachial blood pressure index, cavernosography, sacral evoked response, testosterone and prolactin determination, sexual dysfunction inventory and arousal test.
After one month of treatment with a maximum of 42.0 mg oral yohimbine hydrochloride daily 14% of the patients experienced restoration of full and sustained erections, 20% reported a partial response to the therapy and 65% reported no improvement. In comparison, only three patients reported a positive effect in the placebo group. Maximum effect with yohimbine takes two to three weeks to manifest itself. Yohimbine was active in some patients with arterial insufficiency and a unilateral sacral reflex arc lesion, and in one with low serum testosterone levels. The 34% response is somewhat encouraging given the study population.
Side effects often make yohimbine very difficult to utilize. Yohimbine can induce anxiety, panic attacks, and hallucinations in some individuals. Other side effects include elevations in blood pressure and heart rate, dizziness, headache, and skin flushing. Yohimbine should not be used in individuals with kidney disease, women, and individuals with psychological disturbances
Although crude yohimbe bark preparations are available commercially, use of pure yohimbine hydrochloride is preferred. There are no commercial sources of yohimbe bark that are available to physicians or in health food stores which actually state the level of yohimbine per dosage. Without knowing the content of yohimbine, it is virtually impossible to prescribe an effective and consistent dosage. Because of the yohimbine content of yohimbe bark, the FDA classifies yohimbe as an unsage herb.
Muira puama
Preliminary research indicates one of the best herbs to use for erectile dysfunction or lack of libido may be Muira puama (also known as potency wood). This shrub is native to Brazil and has long been used as a powerful aphrodisiac and nerve stimulant in South American folk medicine. 6 A recent study has validated its safety and effectiveness in improving libido and sexual function in some patients.
At the Institute of Sexology in Paris, France, under the supervision of one of the world's foremost authorities on secual function, Dr, Jacques Waynberg, a clinical study with 262 patients complaining of lack of secual desire and the inability to attain or maintain an erection demonstrated Muira puama extract to be effective in many cases.7 Within two weeks, at a daily dose of 1 to 1.5 grams of the extract (4:1), 62% of patients with loss of libido claimed that the treatment had dynamic effect while 51% of patients with "erection failures" felt that Muira puama was of benefit. These results are extremely promising and seem to indicate that Muira puama may provide better results that yohimbine without side effects.
Presently, the mechanism of action of Muira puama is unknown. From the preliminary information, it appears that it works on enhancing both psychological and physical aspects of sexual function Future research will undoubtedly shed additional light on this extremely promising herb for erectile dysfunction.
References:
1.NIE Consensus Conference Panel on Impotence: Impotence, JAAAMA 270:83-90,1993
2.Lener SE.Melnum A and Chost GJ: a review of erectile dysfunction: New insights and more questions. Journal of Urology149:1216-55,1993
3.Motley JE Management of impotence. Postgraduate Medicine 93:65-72,1991.
4.SussetJG ,et al: Effect of yohimbine hydrochloride on erectile impotence: A double-blindstudy. J. Urology 141:1360-3,1989.
5.Mareales A, et ol: Is yohimbine effective in the treatment of organic impotence? Results of a controlled trial J.Urology 137:1165-72,1987.
6.Duie JA: Handbook of Medicinal Herbs. CRC Press, Boca Raton, FL1985.
7.Waynberg J: Aphrodisiacs: Contributions to the clinical validation of the traditional use of Psych opetalum guyanna. Presented at The Erst International Congress on Ethnopharmaoology', Strasbourg, France June 5-9,1990 (SussetJG et aL Effect of Yohimbine hydrochloride on erectile impotence, a double-blind study. ). Urol 141(6):1360-3,1989.*
CAUSES OF IMPOTENCE
Organic (85%)
Vascular insufficiency
Atherosclerosis
Pelvic surgery
Pelvic trauma
Venous shunting
Drugs
Antihistamines
Antihypertensives
Anticholinergics
Antidepressants
Antipsychotics
Tranquilizers
Others
Alcohol and tobacco
Endocrine disorders
Diabetes
Hypothyroidism
Decreased male sex
hormones
Elevated prolactin levels
High serum estrogen levels
Diseases or trauma to male sexual organs
Diseases of the penis
Prostate disorders
Neurological diseases
Pelvic trauma
Pelvic surgery
Multiple sclerosis
Psychologic (10%)
Psychiatric Illness
Stress
Performance anxiety Depression
Unknown (5%)
GAIA SYMPOSIUM PROCEEDINGS 1993*
NATUROPATHIC HERBAL MEDICINE "Herbal Healing Wisdom for the Future"
May 29,31,1993 Muira Puama
Muira puama, aka potency wood (Ptychopetalum olacoides), is a shrub native to Brazil that has long been used as a powerful aphrodisiac and nerve stimulant in folk medicine. A recent clinical study has validated its safety and effectiveness improving libido and sexual function in men.
At the Institute of Sexology in Paris, France, a clinical study with 262 patients complaining of lack of sexual desire and the inability to attain or maintain an erection demonstrated Muira puama extract (4:1), to be effective in many cases. Within two weeks, at a daily dose of 1 to 15 grams of extract, 62% of patients with loss of libido claimed that the treatment had dynamic effect while 51% of patients with "erection failures" felt that Muira puama was of benefit.
Presently, the mechanism of action of Muira puama is unknown. Future research will undoubtedly shed additional light on this extremely promising herb for i
