Ma Huang

NATURAL PRODUCTS

Ma-Huang (Ephedra sinica)

Ma-Huang is used to help with cough, bronchitis, asthma, and as a stimulant to help stay awake. Several well known companies are marketing and promoting ephedrine from natural sources, under various enticing brand names, as an aid in weight loss by increasing metabolism. It has been called Natural Fen-Phen and Herbal Ecstasy. Prescription ephedrine has been used to treat asthma and its potent CNS stimulatory effects were used to treat narcolepsy, but its use has been limited, due to side effects and safer alternatives. Ephedrine was one of the ingredients in the prescription drug, Marax, in which it was used as a bronchodilator in the treatment of asthma. Ma-Huang contains multiple isomers of ephedrine, including pseudoephedrine, norpseudoephedrine, and norephedrine, which are all sympathomimetic stimulants. Consequently, Ma-Huang can increase blood pressure and cardiac output, which can be dangerous in people with hypertension or cardiac disease. Caution should be exercised with Ma-Huang products, due to purity and safety issues. In some cases, actual dosages may not be what is reflected on the label.

The FDA has approved phenylpropanolamine, not ephedrine, for use as an appetite suppressant in both prescription and over-the-counter (OTC) drugs. It causes less CNS stimulation than ephedrine, but otherwise is approximately equal in potency to ephedrine. The chemical structure of phenylpropanolamine is quite similar to that of ephedrine. As for the use of ephedrine preparations as an aid in weight loss programs, if one looks at controlled studies of its prescription counterparts, long term weight loss effects require it to be taken continuously. Additionally, as with other weight loss products, its effectiveness is enhanced by a solid exercise program and dietary modifications.

Ephedrine preparations for weight loss are not magic bullets. They work primarily as appetite suppressants and significantly less as metabolic stimulants, even though they are marketed as having a "thermogenic effect."

Taking ephedrine-based weight loss preparations with other ephedrine containing products, to help stay awake while driving, can significantly worsen the side effects seen. Such combinations should be avoided and can be dangerous. Likewise, taking ma huang with other products containing sympathomimetics, such as pseudoephedrine may result in an increase in adverse reactions.

Ma Huang is contraindicated in hypertension, closed angle glaucoma, pheochromocytoma, thyrotoxicosis, cerebral vascular disease, cardiac disease, and pregnancy. Drug interactions include digoxin; antihypertensives, including beta blockers, alpha blockers, and guanethidine related products; oxytocin (used in obstetrics to increase uterine contractions); monoamine oxidase inhibitors (MAOI) for depression, like Parnate and Nardil; and phenothiazine drugs. Ma Huang use should be avoided by anybody taking these drugs. There should be at least a 2 week period between stopping an MAOI drug like Parnate and starting Ma Huang, to prevent severe increases in blood pressure. Ma Huang should also be avoided by people taking tricyclic antidepressants, because it can lead to a further increase in blood pressure. Consider ma huang very dangerous in any of these conditions.

Ephedrine is excreted in the urine. Ordinarily this wouldn't be a problem, but in people with impaired renal (kidney) function, the metabolites are not cleared from the body as well as in a person with normal renal function. People with kidney disease should discuss the use of Ma Huang and its recommended dosage with their physician prior to using it.

Studies have shown that ephedrine can cause urinary retention, especially in men with benign prostatic hypertrophy. Ma Huang should be avoided in such cases. Men using saw palmetto to treat benign prostatic hypertrophy and taking Ma Huang may find that the saw palmetto is less effective or may no longer work.

Unlike several other catecholamine sympathomimetics, ephedrine is not metabolized by catechol- O-methyl-transferase (COMT) and monoamine oxidase, the primary enzymes responsible for metabolizing such molecules. Thus it has a significantly longer duration of action. Complicating things further is that tachyphylaxis (a rapidly decreasing response to the drug after only a few doses) can occur with ephedrine. Increasing the dose, in such cases, to get the desired effect may be unsafe and should be avoided.

A single adult dose of ephedrine alkaloid of 15 - 30 mg with a maximum of 300 mg per day is reported in the literature. Most dietary supplement manufacturers are recommending a maximum daily ephedrine alkaloid consumption of no more than 100 mg and no more than 25 mg per serving or dose. Product labeling may be of no value, because some products do not provide the amount to take or list any safety warnings. According to the FDA, Ma Huang doses should be separated by at least 6 hours, due to the duration of action of each dose and to prevent accumulation of ephedrine in the body. The percentage of ephedrine in Ma Huang preparations varies, but many manufacturers report approximately 6% of the herbal extract contains ephedrine. If one was to assume this to be correct, a marketed serving size containing 320 mg Ma Huang would contain 19.2 mg ephedrine, as well as a percentage of pseudoephedrine and other variants as mentioned earlier. At issue here is that the FDA has been monitoring and assessing the number of adverse reactions, due to herbal ephedrine preparations, and has been trying to address the problem with labeling changes and serving size limitations.

The FDA is recommending ephedrine intake be limited to no more than 8 mg in a 6 hour period and not to exceed 24 mg per day, in order to decrease the number of adverse reactions. And the FDA has recommended ephedrine use be limited to 7 days or less. Such a short term use would preclude ephedrine use as a diet aid. The FDA currently limits ephedrine in pharmaceuticals to not exceed 150 mg per day. The FDA is currently reviewing ephedrine in dietary supplements and has retracted their dietary supplement limitations pending further review.

When taken appropriately, Ma Huang may provide an alternative to other treatment options in some people, but due to safety concerns, it may be best to avoid it. Dosing may prove difficult, because depending on the quality of the preparation and patient variability, the amount of Ma-Huang that must be taken to reach an effective single adult dose is quite variable. In addition, some preparations contain vitamins and other stimulants, such as caffeine. Combinations of ephedrine with other stimulants will result in an enhanced effect and an increase in adverse reactions. Such combination products may be unsafe.

Some truck stops and travel plazas sell several different ephedrine alkaloid products to help drivers stay awake. Labeled doses have ranged up to 325 mg per capsule or tablet. The Federal Government is trying to control the sale of ephedrine because it can be used in the manufacture of methamphetamine. In California and other states, ephedrine cannot be sold to anyone younger than 18 years old and the quantity sold cannot exceed 9 grams per transaction. Violations are a misdemeanor.

Legal Info: Solumedia is not responsible for errors or omissions. The information provided on the natural product pages is only a guideline based on current literature and the pharmacological action of these products. It should not be used as the sole source of information on these products. Many of the drug interactions listed are not found in current literature but are based on likely interactions due to the actions of the interacting drugs. It is recommended that a qualified and licensed healthcare professional be consulted for additional information. Although the information provided is from reliable sources, Solumedia has no liability. This information is provided only as a service.

This page was last updated on 04/29/05.