Glaucoma is a condition in which retinal cells die off progressively in a characteristic pattern from pressure buildup in the eyeball, resulting in vision loss and sometimes blindness. However, different people experience vision loss at different levels of intraocular pressure. While high blood pressure, or hypertension, is not directly related to intraocular pressure, some studies have found a correlation between variation in blood pressure and accelerated retinal degeneration in glaucoma patients. Although no research currently exists on the effects of yohimbe in patients with glaucoma, its blood-pressure-increasing side effects are well known. Talk to your doctor before taking any product containing yohimbe.
Use of Yohimbe
The tall, West African evergreen Pausinystalia yohimbe has been used for hundreds of years in the treatment of impotence. Its bark contains more than 30 biologically active alkaloids, many of which act as sedatives, tranquilizers or stimulants. Although little research exists on most of these alkaloids, yohimbine HCl has been used in Western medicine since its approval to treat erectile dysfunction in 1938. Yohimbine HCl, considered yohimbe's principal active constituent, has been largely supplanted by safer pharmaceutical treatments for male sexual dysfunction, although at times, it is still recommended for psychogenic impotence.
Yohimbe Pharmacology
Yohimbe is both a Ca2+ channel blocker and a presynaptic alpha2-adreonreceptor antagonist. It is believed to increase the blood supply to male erectile tissue by paradoxically increasing both sympathetic and parasympathetic nervous system activity. The increase in sympathetic activity is accomplished by stimulating the release of noradrenaline, increasing feelings of energy and excitation, while simultaneously elevating blood pressure. This mechanism of action is quite different from that of the most commonly prescribed pharmaceutical treatments for erectile dysfunciton, sildenafil and tadalafil, which work by inhibiting phosphodiesterase type 5, or PDE5.
Glaucoma Research
Although some research suggests that chronic high blood pressure might contribute to the development of glaucoma, the most worrying research concerns fluctuations in blood pressure. According to Jaewan Choi of the University of Ulsan College of Medicine, major fluctuations in blood pressure over the course of the day can be considered the most consistent clinical risk factor for retinal degeneration in glaucoma patients. Considering yohimbe's hypertensive effects, it might be unwise to take yohimbe if you are suffering from glaucoma.
Side Effects and Contraindications
Because yohimbe is associated with an increase in blood pressure, you should not take it if you have been diagnosed with heart disease or hypertension. According to the National Center for Complementary and Alternative Medicine, yohimbe might also cause elevated heart rate, nausea, vomiting, dizziness, headaches, anxiety or insomnia, according to the National Center for Complementary and Alternative Medicine. Reports of kidney failure have surfaced among some patients taking high doses of yohimbe over long periods of time, so you should not take yohimbe if you are suffering from kidney disease. Consult your doctor if you are considering taking yohimbe, as it might interact with a number of different medications.
References
- University of Maryland Medical Center: Dictionary of Cancer Terms -- Norepinephrine
- Mayo Clinic; "Erectile Dysfunction Herbs: A Natural Treatment for ED?"; Mayo Clinic staff; September 2010
- "Investigative Ophthalmology and Visual Science"; "Circadian Fluctuation of Mean Ocular Perfusion Pressure Is a Consistent Risk Factor for Normal-Tension Glaucoma"; Jaewan Choi et al; November 2007
- "Oftalmologia"; "Daily and Nightly Fluctuation of Intraocular Pressure and Blood Pressure in Glaucoma and Non-Glaucoma Patients"; D. Chiselita; January 2008
