Yohimbine is an
alkaloidAlkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
with
stimulantStimulants are psychoactive drugs which induce temporary improvements in either mental or physical function or both. Examples of these kinds of effects may include enhanced alertness, wakefulness, and locomotion, among others...
and
aphrodisiacAn aphrodisiac is a substance that increases sexual desire. The name comes from Aphrodite, the Greek goddess of sexuality and love. Throughout history, many foods, drinks, and behaviors have had a reputation for making sex more attainable and/or pleasurable...
effects found
naturallyNatural resources occur naturally within environments that exist relatively undisturbed by mankind, in a natural form. A natural resource is often characterized by amounts of biodiversity and geodiversity existent in various ecosystems....
in
Pausinystalia yohimbePausinystalia yohimbe , formerly known as Corynanthe yohimbe, is a psychoactive plant which contains the tryptamine alkaloid yohimbine. It is widely distributed over-the-counter as an herbal aphrodisiac.- References :...
(Yohimbe). It is also found naturally in
Rauwolfia serpentinaRauvolfia serpentina, or 'snakeroot' or 'sarpagandha' is a species of flowering plant in the family Apocynaceae.-Medicinal uses:It is one of the 50 fundamental herbs used in traditional Chinese medicine, where it has the name shégēn mù or yìndù shémù .Rauwolfia serpentina contains a number of...
(Indian Snakeroot),
Alchornea floribundaAlchornea floribunda is a plant native to Sudan, Uganda, Cameroon, Central African Republic, the Republic of Congo, Equatorial Guinea , Gabon, São Tomé and Príncipe, the Democratic Republic of Congo, Côte d'Ivoire, Ghana, Guinea, Liberia, Nigeria and Sierra Leone...
(Niando), along with several other active alkaloids. Yohimbine has been used as both an
over-the-counterOver-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
dietary supplementA dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...
in
herbal extractTincture is a liquid solution of herbs and a fluid menstruum, usually ethanol. The dried or fresh herbs are combined with alcohol, then the solid matter is removed leaving only the oils of the herbs mixed with the alcohol...
form and
prescriptionA prescription medication is a licensed medicine that is regulated by legislation to require a medical prescription before it can be obtained. The term is used to distinguish it from over-the-counter drugs which can be obtained without a prescription...
medicineMedicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
in pure form for the
treatmentThis is a list of types of therapy .* Adventure therapy* Animal-assisted therapy* Aquatic therapy* Aromatherapy* Art and dementia* Art therapy* Authentic Movement* Behavioral therapy* Bibliotherapy* Buteyko Method* Chemotherapy...
of
sexual dysfunctionSexual dysfunction or sexual malfunction refers to a difficulty experienced by an individual or a couple during any stage of a normal sexual activity, including desire, arousal or orgasm....
. Yohimbine was explored as a remedy for type 2 diabetes in animal and human models carrying polymorphisms of the α
2A-adrenergic receptor gene.
Sexual
The
NIHThe National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...
states that yohimbine hydrochloride is the standardized form of yohimbine that is available as a prescription medicine in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and has been shown in human studies to be effective in the treatment of male impotence.
Yohimbine Hydrochloride, USP—a standardized form of yohimbine—is a prescription medicine that has been used to treat erectile dysfunction. Controlled studies suggest that it is not always an effective treatment for impotence, and evidence of increased sex drive (libido) is anecdotal only.
Yohimbine blocks the pre- and post-synaptic alpha-2 adrenoceptors. Blockade of post-synaptic alpha-2 adrenoceptors leads to minor corpora cavernosa smooth muscle relaxation. In fact the majority of adrenoceptors in the corpora cavernosa are alpha-1. Blockade of pre-synaptic alpha-2 adrenoceptors leads to increased release of neurotransmitters in the Central Nervous System and in the corpora cavernosa penis such as nitric oxide, noradrenaline and dopamine. Whether Nitric Oxide released in the corpora cavernosa has a relaxing effect, noradrenaline has a much powerful constricting effect by stimulating the unblocked alpha-1 adrenoceptors. Concomitant use of an alpha-1 blocking agent will prevent constriction caused by the increased adrenergic stimulation.
Pausinystalia Yohimbe (Yohimbe) doesn't contain just Yohimbine. It contains around 55 other alkaloids and Yohimbine accounts for 1% to 20% of total alkaloids. Among them Corynanthine is an alpha-1 adrenoceptor blocker. Hence the use of Yohimbe extract in sufficient dosages may provide concomitant alpha-1 and alpha-2 adrenoceptors blockade and thus may better enhance erections then Yohimbine alone.
Yohimbine has been shown to be effective in the reversal of sexual satiety and exhaustion in male rats. Yohimbine has also been shown to increase the volume of ejaculated semen in dogs, with the effect lasting at least five hours after administration. Yohimbine has been shown to be effective in the treatment of orgasmic dysfunction in men.
Fat loss
According to one study, oral yohimbine supplementation may actuate significant fat loss in athletes. Numerous bodybuilding supplement companies sell formulations of yohimbine for
transdermalTransdermal is a route of administration wherein active ingredients are delivered across the skin for systemic distribution. Examples include transdermal patches used for medicine delivery, and transdermal implants used for medical or aesthetic purposes....
delivery to effect a local reduction of
adipose tissueIn histology, adipose tissue or body fat or fat depot or just fat is loose connective tissue composed of adipocytes. It is technically composed of roughly only 80% fat; fat in its solitary state exists in the liver and muscles. Adipose tissue is derived from lipoblasts...
, although the experimental evidence for its efficiency is limited.
Other uses
Yohimbine has also been used for the treatment of sexual side effects caused by some antidepressants (SSRIs), female hyposexual disorder, as a blood pressure boosting agent in autonomic failure,
xerostomiaXerostomia is the medical term for the subjective complaint of dry mouth due to a lack of saliva. Xerostomia is sometimes colloquially called pasties, cottonmouth, drooth, or doughmouth. Several diseases, treatments, and medications can cause xerostomia. It can also be exacerbated by smoking or...
, and as a probe for noradrenergic activity.
The addition of yohimbine to
fluoxetineFluoxetine is an antidepressant of the selective serotonin reuptake inhibitor class. It is manufactured and marketed by Eli Lilly and Company...
or
venlafaxineVenlafaxine is an antidepressant of the serotonin-norepinephrine reuptake inhibitor class. First introduced by Wyeth in 1993, now marketed by Pfizer, it is licensed for the treatment of major depressive disorder , as a treatment for generalized anxiety disorder, and comorbid indications in...
has also been found to potentiate the antidepressant action of both of these agents.
Yohimbine has been used to facilitate recall of traumatic memories in the treatment of post traumatic stress disorder (PTSD). Use of yohimbine outside therapeutic settings may not be appropriate for persons suffering from PTSD.
In pharmacology, yohimbine is used as a probe for α
2-adrenoceptor.
In
veterinary medicineVeterinary Medicine is the branch of science that deals with the prevention, diagnosis and treatment of disease, disorder and injury in non-human animals...
, yohimbine is used to reverse
anesthesiaAnesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
from the drug
xylazineXylazine is a drug that is used for sedation, anesthesia, muscle relaxation, and analgesia in animals such as horses, cattle and other non-human mammals. An analogue of clonidine, it is an agonist at the α2 class of adrenergic receptor....
in small and large animals.
Pharmacology
Yohimbine has high affinity for the
α2-adrenergic receptorThe alpha-2 adrenergic receptor is a G protein-coupled receptor associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well...
, moderate affinity for the
α1-adrenergicThe alpha-1 adrenergic receptor is a G protein-coupled receptor associated with the Gq heterotrimeric G-protein. It consists of three highly homologous subtypes, including α1A-, α1B-, and α1D-adrenergic...
, 5-HT
1A, 5-HT
1B, 5-HT
1D, 5-HT
1F, 5-HT
2B, and D
2 receptors, and weak affinity for the 5-HT
1E, 5-HT
2A, 5-HT
5A, 5-HT
7, and D
3 receptors. It behaves as an
antagonistA receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
at α
1-adrenergic, α
2-adrenergic, 5-HT
1B, 5-HT
1D, 5-HT
2A, 5-HT
2B, and D
2, and as a
partial agonistPartial agonists bind and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist...
at 5-HT
1A. Its
intrinsic activitiesIntrinsic activity or efficacy refers to the relative ability of a drug-receptor complex to produce a maximum functional response. This must be distinguished from the affinity, which is a measure of the ability of the drug to bind to its molecular target, and the EC50, which is a measure of the...
at the other sites listed are unclear/unknown, but it is probably mostly antagonistic at them.
Production
Yohimbine is the principal alkaloid of the bark of the West African evergreen
Pausinystalia yohimbePausinystalia yohimbe , formerly known as Corynanthe yohimbe, is a psychoactive plant which contains the tryptamine alkaloid yohimbine. It is widely distributed over-the-counter as an herbal aphrodisiac.- References :...
(formerly
Corynanthe yohimbe), family
RubiaceaeThe Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...
(Madder family). There are 31 other yohimbane alkaloids found in Yohimbe. In Africa, yohimbe has traditionally been used as an
aphrodisiacAn aphrodisiac is a substance that increases sexual desire. The name comes from Aphrodite, the Greek goddess of sexuality and love. Throughout history, many foods, drinks, and behaviors have had a reputation for making sex more attainable and/or pleasurable...
. However, it is very important to note that while the terms
yohimbine,
yohimbine hydrochloride, and
yohimbe bark extract are related, they are not interchangeable.
The main active chemical present in yohimbe bark is yohimbine HCl (indole alkaloid), found in the bark of the Pausinystalia yohimbe tree.
However, the levels of yohimbine that are present in yohimbe bark extract are variable and often very low. Therefore, although yohimbe bark has been used traditionally to reduce male erectile dysfunction, there is not enough scientific evidence to form a definitive conclusion in this area.
The tree is currently threatened with extinction in its native habitat due to international demand. Its conservation is difficult because the bioactivity of the tree has led many Western governments to declare it a proscribed species.
Adverse effects
Yohimbine has significant side effects, such as anxiety reactions. According to the Mayo Clinic, yohimbine can be dangerous if used in excessive amounts.
Higher doses of oral yohimbine may create numerous side effects, such as
rapid heart rateTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
, high blood pressure, overstimulation,
insomniaInsomnia is most often defined by an individual's report of sleeping difficulties. While the term is sometimes used in sleep literature to describe a disorder demonstrated by polysomnographic evidence of disturbed sleep, insomnia is often defined as a positive response to either of two questions:...
and/or sleeplessness. Some effects in rare cases were panic attacks, hallucinations, headaches,
dizzinessDizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, and
skin flushingFor a person to flush is to become markedly red in the face and often other areas of the skin, from various physiological conditions. Flushing is generally distinguished, despite a close physiological relation between them, from blushing, which is milder, generally restricted to the face, cheeks or...
.
More serious adverse effects may include seizures and
renal failureRenal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
. Yohimbine should not be consumed by anyone with
liverLiver disease is a broad term describing any single number of diseases affecting the liver.-Diseases:* Hepatitis, inflammation of the liver, caused mainly by various viruses but also by some poisons , autoimmunity or hereditary conditions...
, kidney,
heart diseaseHeart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
, or a psychological disorder.
The
therapeutic indexThe therapeutic index is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes death or toxicity ....
of yohimbine is quite low; the range between an effective dose and a dangerous dose is very narrow. This may also lead to precipitation of panic disorder type reactions.
Yohimbine in combination with
modafinilModafinil is an analeptic drug manufactured by Cephalon, and is approved by the U.S. Food and Drug Administration for the treatment of narcolepsy, shift work sleep disorder, and excessive daytime sleepiness associated with obstructive sleep apnea...
is frequently associated with nausea, dangerous acute rapid heart beat, and acute increased blood pressure. Yohimbine exhibits some degree of MAOI activity while
modafinilModafinil is an analeptic drug manufactured by Cephalon, and is approved by the U.S. Food and Drug Administration for the treatment of narcolepsy, shift work sleep disorder, and excessive daytime sleepiness associated with obstructive sleep apnea...
has been shown to increase levels of various monamines, and therefore could result in severe risk of dangerous side effects.
See also
- Ajmalicine
Ajmalicine, also known as δ-yohimbine or raubasine, is an antihypertensive drug used in the treatment of high blood pressure. It has been marketed under numerous brand names including Card-Lamuran, Circolene, Cristanyl, Duxil, Duxor, Hydroxysarpon, Iskedyl, Isosarpan, Isquebral, Lamuran, Melanex,...
- Corynanthine
Corynanthine, also known as rauhimbine, is an alkaloid found in the Rauwolfia and Pausinystalia genera of plants. It is one of the two diastereoisomers of yohimbine, the other being rauwolscine...
- Rauwolscine
Rauwolscine, also known as isoyohimbine, α-yohimbine, and corynanthidine, is an alkaloid found in various species within the genera Rauwolfia and Pausinystalia . It is a stereoisomer of yohimbine...
- Reserpine
Reserpine is an indole alkaloid antipsychotic and antihypertensive drug that has been used for the control of high blood pressure and for the relief of psychotic symptoms, although because of the development of better drugs for these purposes and because of its numerous side-effects, it is rarely...
- Deserpidine
Deserpidine is an antihypertensive drug related to reserpine.-References:...
- Rescinnamine
Rescinnamine is an angiotensin-converting enzyme inhibitor used as an antihypertensive drug.It is an alkaloid obtained from Rauwolfia serpentina and other species of Rauwolfia....
External links