Yohimbe and Nausea

In West Africa, the bark of the tall, evergreen Pausinystalia yohimbe tree has been used as an aphrodisiac and treatment for sexual dysfunction for generations. The bark contains over 30 pharmacologically active chemicals known as alkaloids, the most potent of which is known as yohimbine. Although yohimbine was approved as a pharmaceutical treatment for erectile dysfunction in 1938, the other alkaloids have not been as extensively researched. Many of these chemicals act as sedatives, tranquilizers, or central nervous system stimulants, and can have moderate to severe side effects. While the drug yohimbine has been mostly supplanted by safer, next-generation treatments for impotence, extracts of yohimbe bark are still commonly used in alternative medicine. Due to the possibility of nausea or more serious side effects, it is recommended that you talk to your doctor before taking products containing yohimbe.

Mechanism

Yohimbe has no effects on testosterone of the male glandular system. The effects of yohimbe on male erectile tissue are believed to be accomplished predominantly through central nervous system activity. Yohimbine acts as a presynaptic alpha2-adreonoreceptor blocker, which increases the nervous system activity needed for erection. Paradoxically, the same alkaloid also acts as a stimulant by increasing the production of noradrenaline, decreasing appetite and increasing your heart rate and blood pressure. While drugs that cause stimulation or sedation through this pathway can cause nausea, the combination of both makes nausea much more likely. According to the Memorial Sloan-Kettering Cancer Center, yohimbe also causes the body to divert blood to cavernous tissue such as the genitals.

Other Active Alkaloids

Although yohimbine is the plant's most potent alkaloidal constituent, it is possible that some of yohimbe's other chemicals contribute to its action. Both corynantheine and dicorynantheine are central nervous system sedatives and tranquilizers, as is ajmaline. By promoting parasympathetic nervous system activity over sympathetic activity, these alkaloids may further promote genital tissue erection. Taken alone, each of these chemicals may also cause nausea, so it would be safe to assume that formulations containing the whole herb may produce more nausea than those containing pure yohimbine.

Side Effects and Contraindications

Other side effects produced by yohimbe may include headache, restlessness, anxiety, difficulty sleeping, loss of appetite, hypertension, and racing heart. If you suffer from high blood pressure, kidney disease, or heart disease, do not take yohimbe. Yohimbe may also decrease the time needed to achieve orgasm by increasing genital sensitivity and reflex excitability in nerves in the sacral region. This nerve stimulation may also produce the sensation of pins-and-needles, tingling, or shivers in the spine or lower back.

Drug Interactions

Although yohimbine HCl is mentioned by MayoClinic.com as a specific treatment for psychogenic impotence, yohimbe has been known to interact dangerously with a number of antidepressant medications. If you are taking either tricyclic or monoamine oxidase inhibiting antidepressants, you should not take yohimbe. This may result in a fatal drug interaction, according to the Memorial Sloan-Kettering Cancer Center. Due to its stimulant properties, yohimbe should not be combined with other stimulants. According to MayoClinic.com, both the antidepressant bupropion and the stimulant methamphetamine can be considered toxic when combined with yohimbe.