This is a derivative of the plant Hypericum perforatum used for the treatment of mild depression. It can be obtained as a tea, capsule, or oil. St. John’s wort contains several active ingredients that have a variety of effects on neurochemical signals in the central nervous system. It has undergone significant scientific testing including double blind clinical trials and is widely used in Germany.
Garlic: Garlic is commonly used among hypertensive patients because of its reputed benefit in reducing cardiovascular disease and lowering BP. Other claims for the benefits of garlic have included cancer prevention and anti-inflammation.
Yohimbine: This is a prescription drug that has been available for about 30 years and has long been known to be present in the bark of a West African tree. The bark product contains several alkaloids including yohimbine that may be present in varying amounts. Yohimbine is a presynaptic a2-adrenergic blocking agent and possibly a monoamine oxidase inhibitor. It also has other effects on the autonomic nervous system. Although not available as an over-the-counter product, it can be found in herbal and supplement stores and is promoted as treatment for erectile dysfunction.
Licorice: It is marketed for the treatment of stomach disorders and is associated with a form of pseudoaldosteronism manifesting as weight gain, hypertension, hypokalemia, and metabolic alkalosis. The implicated substance is glycyrrhizic acid that inhibits 11-ß-hydroxysteroid dehydrogenase33 and hence increased levels of cortisol that combine with the mineralocorticoid receptor (an acquired apparent mineralocorticoid excess). The disorder reverses within a few days on cessation of intake of licorice but may be associated with hypertensive encephalopathy34 and chronic refractory hypertension.35,36
However, It is essential for all physicians treating hypertension to obtain a history of any herbal, dietary, or supplement use from all patients. Because of the potency of the effect of grapefruit juice on several drugs used in hypertensive patients, specific questioning is needed about this. The number and complexities of such substances and their possible interactions with cardiovascular drugs make it imperative that a written or electronic reference source be immediately available for consultation. Serious consideration should be given to having all patients attending a hypertension clinic discuss use of any such products with their physician before intake. Case reports and case series of hypertensive emergencies and serious cardiovascular complications illustrate the serious adverse effects that may occur. More vigilance is needed in monitoring the use of herbals, supplements, and other nontraditional medications in the hypertensive population.
