Ephedra sinica

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References

Astrup A,Toubro S. Thermogenic, metabolic, and cardiovascular responses to ephedrine and caffeine in man. Int J Obes Relat Metab Disord 1993 Feb;17 Suppl 1:S41-43
Abstract: To develop an appropriate combination of ephedrine and caffeine consisting of clinically relevant doses, we examined the acute thermogenic, metabolic, and cardiovascular effects of different doses of caffeine (C) and ephedrine (E) given separately and in combination to normal subjects. The thermogenic effect after E+C (20 mg/200mg) was larger than that of any other combinations, and E and C exerted a supra- additive synergism on thermogenesis and systolic blood pressure, while being without effect on diastolic blood pressure. The combination also had pronounced effects on glucose metabolism by increasing plasma glucose, insulin and C-peptide concentrations. During chronic treatment the effect of E+C on energy expenditure is maintained, while side effects subside because tolerance develops to its hemodynamic and metabolic effects. During dietary energy restriction E+C promotes fat loss and preserves fat-free mass, which may contribute to its chronic effect on energy balance. In conclusion, the hemodynamic and side effects to E+C are transient during chronic treatment, while the effect on energy expenditure persists. The compound also possesses repartitioning properties, which may be useful in the treatment of obesity.

Backer R, Tautman D, Lowry S, Harvey CM, Poklis A. Fatal ephedrine intoxication. J Forensic Sci 1997 Jan;42(1):157-159.
Abstract: A 28-year-old white female with a history of two prior suicide attempts was found dead in her home by her common law husband. Autopsy findings were unremarkable except for partially dissolved ephedrine tablets in the stomach contents. Quantitation of ephedrine was by gas chromatography/mass spectrometry (GC/MS) following liquid/liquid extraction from alkaline samples and pentafluoropropionic acid derivatization. Significant toxicological finding included ephedrine; blood, 11 mg/L; liver, 24 mg/kg; kidney, 14 mg/kg; brain, 8.9 mg/kg; and amitriptyline; blood, 0.33 mg/kg; liver 7.8 mg/kg. The ephedrine values found far exceed those associated with therapeutic administration and are consistent with the few reported cases of severe ephedrine intoxication. The cause of death was determined to be fatal ephedrine intoxication and manner of death suicide.

Bensky, Gamble A, Kaptchuck T. Chinese Herbal Medicine: Materia Medica. Revised Edition. Seattle: Eastland Press, 1993.

Blumenthal M, Busse WR, Goldberg A, et al, eds. The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998.

Brooks SM, Sholiton LJ, Werk EE Jr, Altenau P. The effects of ephedrine and theophylline on dexamethasone metabolism in bronchial asthma. J Clin Pharmacol 1977 May-Jun;17(5-6):308-318.
Abstract: The effect of ephedrine (nine patients) and theophylline (seven patients) on dexamethasone metabolism was studied before and after three weeks of drug therapy in 16 asthmatics. Five patients were studied similarily but treated with placebo. After treatment with ephedrine, there was a mean decrease in plasma dexamethasone half-life (t1/2) of 132 minutes, or 36 per cent (P less than 0.025), and mean increase in metabolic clearance rate (MCR) of 148 liters/day, or 42 per cent (P less than 0.001). Increase in the excretion of urinary radioactivity, predominantly in the conjugated fractions, was noted. In contrast, theophylline and placebo therapy resulted in no significant changes in dexamethasone t1/2 or MCR. The rate of urinary excretion of radioactivity was reduced after theophylline treatment. Since ephedrine accelerates labeled dexamethasone clearance while theophylline does not, caution is necessary when prescribing ephedrine for asthmatics requiring long-term therapy with dexamethasone and probably other corticosteroids. It would appear from the present investigation that theophylline is a more appropriate bronchodilator for these patients.

Bruno A, Nolte KB, Chapin J. Stroke associated with ephedrine use. Neurology 1993 Jul; 43(7):1313-1316.
Abstract Several sympathomimetic agents have been associated with ischemic and hemorrhagic stroke. Ephedrine, a sympathomimetic drug that has a high potential for abuse and can be readily obtained without a prescription in unrestricted quantities, has rarely been associated with stroke. We report ephedrine-related stroke in three patients. One patient developed a thalamic infarct after ingesting known quantities of ephedrine as street-purchased "speed" for weight loss. Two patients had fatal intracranial hemorrhages after ingesting unknown quantities of ephedrine; one of them had a history of drug abuse, and one lacked a history of ephedrine use or drug abuse. Ephedrine appears to predispose to both ischemic and hemorrhagic stroke. The mechanisms responsible for the different cerebrovascular complications remain to be proven. Restriction of ephedrine availability should be considered.

Cockings JG, Brown M. Ephedrine abuse causing acute myocardial infarction. Med J Aust 1997 Aug 18;167(4):199-200.
Abstract: "On the street", the more expensive illegal psychostimulants, such as cocaine or amphetamine, may be mixed with or substituted for cheaper drugs such as ephedrine-with added risk to the user. We report diffuse myocardial injury in a 25-year-old man who presented with pulmonary oedema after intravenously injecting himself with ephedrine, believing it to be amphetamine.

D'Arcy PF. Traditional Chinese medicines: safety hazards. Adverse Drug React Toxicol Rev 1999 Jun;18(2):53-57.

Gurley BJ, Gardner SF, White LM,Wang PL. Ephedrine pharmacokinetics after the ingestion of nutritional supplements containing Ephedra sinica (ma huang). Ther Drug Monit 1998 Aug;20(4):439-445.
Abstract: Nutritional supplements containing Ephedra sinica (ma huang), a botanical source of ephedrine alkaloids, have been linked to several episodes of ephedrine toxicity and at least 17 deaths, yet these products remain unregulated. Ten subjects were enrolled in a randomized, crossover studyaimed at characterizing the pharmacokinetics of ephedrine after the ingestion of three commercially available ma huang products compared with a 25-mg ephedrine capsule. Pharmacokinetic parameters for botanical ephedrine were similar to those for synthetic ephedrine hydrochloride. Gender-based comparisons of Vss/F and CL/F revealed higher values for women than for men (Vss/F, 3.49 +/- 1.04 vs 2.98 +/- 0.73 l/kg; CL/F, 0.48 +/- 0.11 vs 0.37 +/- 0.11 l/hour x kg). The current study suggests that the increased incidence of ma huang toxicity does not stem from differences in the absorption of botanical ephedrine compared with synthetic ephedrine; rather, it results from accidental overdose often prompted by exaggerated off-label claims and a belief that "natural" medicinal agents are inherently safe.

Hikino H, Ogata K, Konno C, Sato S. 1983. Hypotensive actions of ephedradines, macrocyclic spermine alkaloids of Ephedra roots. Planta Med 1983 Aug;48(4):290-293.

Hsu H. Oriental Materia Medica, Taiwan, R.O.C.: OHAI 1986.
 
Huang KC. The Pharmacology of Chinese Herbs, Ann Arbor, MI: CRC Press 1993.

Ling M; Piddlesden SJ; Morgan 1995. A component of the medicinal herb ephedra blocks activation in the classical and alternative pathways of complement. Clin Exp Immunol 1995 Dec;102(3):582-588
ABSTRACT: Extracts of the herb Ephedra sinica have long been used in traditional Chinese medicine for the treatment of, among other conditions, acute nephritis. In preliminary studies it was shown that extracts of ephedra caused inhibition of complement in vitro. We thus set out to isolate the active component(s) of this herb, to examine the complement- inhibiting capacity in sera from different species, and to characterize the mechanism(s) by which it inhibits complement. Aqueous extraction of the herb followed by fractionation using thin layer chromatography (TLC) demonstrated that complement-inhibiting activity resided within a single band, hereafter termed the complement-inhibiting component (CIC), which represents an as yet uncharacterized polyanionic carbohydrate molecule. TLC-purified CIC inhibited the classical complement pathway in all species tested (human, pig, guinea pig, rat and rabbit). Using erythrocyte intermediates and sera specifically depleted of individual components it was apparent that CIC inhibited C2. This finding was confirmed using purified human C2, CIC causing a dose-dependent loss of C2 haemolytic activity. At much higher doses, CIC also showed some inhibiting effect in the terminal pathway, and this was shown to be due to inhibition of C9. In the alternative pathway CIC also showed inhibitory activity, although its site of action in this pathway remains unresolved. In Chinese medicine the herb is taken orally, though no studies of complement levels in patients taking the herb have been reported. Preliminary data indicate that oral administration in rats causes a partial inhibition of serum complement activity. Given the current enthusiasm for complement inhibition as a therapy for inflammatory diseases, this non-toxic, naturally occurring agent might be of therapeutic value.

Jubiz W, Meikle AW. Alterations of glucocorticoid actions by other drugs and disease states. Drugs 1979 Aug;18(2):113-121.
Abstract: Glucocorticoids are used in physiological and pharmacological amounts in the management of a variety of clinical conditions. Concomitant utilisation of other drugs or the presence of some diseases may affect the physiological action of the steroid in the tissues. Phenytoin, phenobarbitone, ephedrine and rifampicin accelerate the metabolism of glucocorticoids thereby decreasing their biological activity. A similar phenomenon occurs in patients with hyperthyroidism. In contrast, glucocorticoid action is enhanced in hypothyroid patients and in those with hepatic damage as the result of a defect in the clearance of the hormone from blood. In turn, glucocorticoids antagonise the effects of cholinesterase inhibitors and ganglion blocking agents. The above mentioned effects should be kept in mind whenever glucocorticoids are utilised in the diagnosis and management of endocrine or non-endocrine conditions.

Kalix P. The pharmacology of psychoactive alkaloids from ephedra and catha. J Ethnopharmacol 1991 Apr;32(1-3):201-208.
Abstract: Ever since the introduction of the alkaloid ephedrine as an anti- asthmatic, the CNS stimulatory effects of this sympathomimetic have been a problem in therapy. Indeed, the use of ephedrine is not only limited by its cardiovascular effects, but also by the occurrence of insomnia, restlessness and anxiety. Exceptionally, ephedrine may even induce toxic psychosis, and the possibility of this side effect has recently received renewed attention. Besides ephedrine, the ephedra plant contains some norpseudoephedrine. This substance is also called cathine, because it is a major alkaloid of Catha edulis or khat, a plant that is widely used as a stimulant in certain countries of East Africa and of the Arab Peninsula. The effects of khat have been explained formerly by those of cathine; some time ago, however, the labile alkaloid cathinone was discovered in khat. This substance is the keto-analog of cathine; it is therefore more lipophilic and penetrates easily to its sites of action in the central nervous system. Indeed, cathinone has been found to be a highly potent CNS stimulant and it is now known to be the main psychoactive constituent of khat; the results of various in vitro and in vivo studies indicate that cathinone must be considered a natural amphetamine. In confirmation of this view, it has recently been demonstrated that cathinone has in humans marked euphorigenic and psychostimulant effects. As the case may be, these findings may lead, together with epidemiological data, to a reconsideration of the use of khat as a stimulant and social drug.

Mills SY. The Essential Book of Herbal Medicine. Arkana, NY. 1991.

MMWR. Adverse events associated with ephedrine-containing products--Texas, December 1993-September 1995. Morb Mortal Wkly Rep 1996 Aug 16;45(32):689-693
Abstract: During December 1993-September 1995, the Bureau of Food and Drug Safety, Texas Department of Health (TDH), received approximately 500 reports of adverse events in persons who consumed dietary supplement products containing ephedrine and associated alkaloids (pseudoephedrine, norephedrine, and N-methyl ephedrine). This total included reports by individuals and reports identified by the Bureau of Epidemiology, TDH, in a review of records from the six centers of the Texas Poison Center Network. Reported adverse events ranged in severity from tremor and headache to death in eight ephedrine users and included reports of stroke, myocardial infarction, chest pain, seizures, insomnia, nausea and vomiting, fatigue, and dizziness. Seven of the eight reported fatalities were attributed to myocardial infarction or cerebrovascular accident. This report describes three patients in which the recommended dosage for the dietary supplements reportedly was not exceeded, summarizes results from ongoing investigations, and underscores the potential health risks associated with the use of products containing ephedrine.

Molenaar PC, Biewenga JE, Van Kempen GT, De Priester JA. Effect of ephedrine on muscle weakness in a model of myasthenia gravis in rats. Neuropharmacology 1993 Apr;32(4):373-6
Abstract: In addition to therapy with anticholinesterases, ephedrine is sometimes used to improve muscle strength in myasthenia gravis, with variable results. The efficacy of ephedrine was tested in rats with a alpha- bungarotoxin-induced model of myasthenia gravis. The rats showed a drooping lower lip and impaired capability of drinking. Injections of neostigmine caused an improvement of the position of the lip. Ephedrine caused some improvement. However, ephedrine had no effect, either on the lower lip or on water consumption, when the sleep-wake cycle was reversed and the rats had their active period during day time. It was concluded that the effect of ephedrine was unspecific and probably due to arousal from drowsiness. The results suggest, therefore, that the variability of the effect of ephedrine in myasthenic patients is unrelated to neuromuscular transmission per se but rather due to a difference in susceptibility to arousal.

Moore M. Mormon Tea, In: Medicinal Plants of the Pacific West. Santa Fe, NM: Red Crane Books, 1993

Nikaido T, et al. 1990. [The study on Chinese herbal medicinal prescription with enzyme inhibitory activity. III. The study of mao-to with adenosine 3',5'- cyclic monophosphate phosphodiesterase] Yakugaku Zasshi (1990 Jul) 110(7):504-508. [Published in Japanese]
Abstract: Mao-to, a Chinese herbal medicinal prescription was studied for the inhibitory activity of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase. The inhibitory activity for this enzyme depended mainly on Ephedra herb and Glycyrrhiza in this prescription. Apricot kennel acted as a mitigatory component for Ephedra herb in cAMP phosphodiesterase inhibitory test. In ephedrine and the related compounds the inhibitory activity of cAMP phosphodiesterase was not shown.

Nikaido T, Iizuka S, Okada N, Kuge T, Ohmoto T. 1992 [The study of Chinese herbal medicinal prescription with enzyme inhibitory activity. VI. The study of makyo-kanseki-to with adenosine 3',5'-cyclic monophosphate phosphodiesterase] Yakugaku Zasshi (1992 Feb) 112(2):124-128. [Published in Japanese]
Abstract: A Chinese herbal medicinal prescription, Makyo-kanseki-to, was studied for the inhibitory activity of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase. The effect for the inhibitory activity of cAMP phosphodiesterase by combination with constituent crude drugs of the prescription was studied. Gypsum acted as a mitigatory component for Ephedra herb and Glycyrrhiza in cAMP phosphodiesterase inhibition test.

Noguchi M, Kubo M, Naka Y. [Studies on the pharmaceutical quality evaluation of crude drug preparations used in Orient medicine "Kampoo". IV. Behavior of alkaloids in ephedra herb mixed with other crude drugs under decoction processes]. Yakugaku Zasshi. 1978 Jul;98(7):923-928. [Article in Japanese]

Powell T, Hsu FF, Turk J, Hruska K. Ma-huang strikes again: ephedrine nephrolithiasis. Am J Kidney Dis 1998 Jul;32(1):153-159
Abstract: Ephedrine and its metabolites are naturally occurring alkaloids that can be derived from evergreens worldwide and have been used as medicinals for hundreds of years. Because they have "real" pharmacological alpha and beta catecholamine effects and are "natural" products, the alternative medicine industry has popularized them for multiple uses, including asthma, weight loss, energy and sexual enhancement, and euphoria. Several recent reviews have documented the dangerous nature of using these "drugs" unsupervised, including multiple deaths, and the FDA is currently reviewing ephedrine's use in the alternative medicine industry. We report a new toxicity, ephedrine nephrolithiasis, in a patient using an energy supplement, Ma-Huang extract, which contains ephedrine. Although previously not reported, the Louis C. Herring and Company kidney stone database show that this is an endemic complication of ephedrine with hundreds of previous episodes. Using gas chromatography (GC) mass spectrometry, we were able to positively identify the chemical structure of our patient's stone, as well as other similar stones from Louis Herring, as containing ephedrine, norephedrine, and pseudoephedrine.

Shufman NE, Witztum E,Vass A. [Ephedrine psychosis] Harefuah 1994 Sep;127(5-6):166-8, 215.
Abstract: Ephedrine has both alpha- and beta-adrenergic activity, and both direct and indirect effects on receptors. Its stimulatory effects on the central nervous system are more prolonged, though less potent, than those of adrenalin. It raises blood pressure both by increasing cardiac output and inducing peripheral vasoconstriction. It is still commonly used as a bronchodilator. However, since prolonged use leads to decreased effectiveness, patients tend to increase the dose themselves. The clinical picture of ephedrine psychosis resembles that induced by amphetamines: primarily a paranoid psychosis with delusions of persecution and auditory and visual hallucinations in a setting of unclouded consciousness. We present a 57-year-old woman who had been taking a usual dose of ephedrine for bronchial asthma (50 mg 3 times a day) for more than 30 years. When her husband died she developed depression, for which she tried to use ephedrine as an antidepressive, increasing the dose to 500 to 1000 mg a day over the course of half a year. She developed paranoid psychosis with delusions of persecution and auditory hallucinations, despite a clear sensorium. Recovery was rapid after ephedrine was gradually reduced to 200 mg a day and a small dose (200 mg) of the neuroleptic thioridazine was added.

Sieb JP, Engel AG.Ephedrine: effects on neuromuscular transmission. Brain Res 1993 Sep 24;623(1):167-167.
Abstract: (-)-Ephedrine has been used in the treatment of patients with myasthenia gravis. To investigate the possible effects of ephedrine on neuromuscular transmission, canine intercostal muscle endplates were studied by microelectrode techniques. At concentrations less than 10(- 4) M, ephedrine had no effect on neuromuscular transmission. At a concentration of 10(-4) M, ephedrine increased the quantal content of the endplate potential by 21%. The presynaptic store of acetylcholine quanta available for immediate release was unchanged, but the probability of quantal release was increased by 16%. At this concentration, ephedrine decreased the amplitude of the miniature endplate potential by 38%. In the presence of 10(-3) M ephedrine, the miniature endplate potentials and currents became undetectable. The kinetic properties of the acetylcholine receptor channel were studied by analysis of acetylcholine-induced endplate current noise. At 10(-4) M, ephedrine reduced the channel conductance by 43% but had no effect on the open time. At 5 x 10(-4) M, ephedrine reduced the channel conductance by 84% and increased the open time by 23 percent.

Threlkeld DS, ed. Central nervous system drugs, antidepressants, monoamine oxidase inhibitors. In: Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997.

Toubro S, Astrup AV, Breum L, Quaade F. Safety and efficacy of long-term treatment with ephedrine, caffeine and an ephedrine/caffeine mixture. Int J Obes Relat Metab Disord 1993 Feb;17 Suppl 1:S69-72.
Abstract: In a randomized, placebo-controlled, double blind study, 180 obese patients were treated by diet (4.2 MJ/day) and either an ephedrine/caffeine combination (20mg/200mg), ephedrine (20mg), caffeine (200mg) or placebo 3 times a day for 24 weeks. 141 patients completed this part of the study. All medication was stopped between week 24-26 in order to catch any withdrawal symptoms. From week 26 to 50, 99 patients completed treatment with the ephedrine/caffeine compound in an open trial design, resulting in a statistically significant (p = 0.02) weight loss of 1.1kg. In another randomized, double-blind, placebo- controlled 8 week study on obese subjects we found the mentioned compound showed lean body mass conserving properties. We conclude that the ephedrine/caffeine combination is effective in improving and maintaining weight loss, further it has lean body mass saving properties. The side effects are minor and transient and no withdrawal symptoms have been found.

Tricker AR, Wacker CD, Preussmann R. Nitrosation products from the plant Ephedra altissima and their potential endogenous formation. Cancer Lett 1987 May;35(2):199-206.
Abstract: The plant species Ephedra is commonly used in both folk medicine and for the preparation of health teas. Nitrosation of a tea made from Ephedra altissima yielded N-nitrosoephedrine (NEP), N- nitrosopseudoephedrine (NPEP), N-nitrosoproline (NPRO), N- nitrosomethylbenzylamine (NMBA), trace quantities of 2 unidentified non- volatile nitrosamines and the new nitroso compound 2-(N-nitroso-N- methylamino)propiophenone (NMAP). Incubation of a tea extract at 37 degrees C and pH 2.0 under conditions simulating the normal fasting stomach with a constant nitrite concentration (25 microM) for 1 h produced NEP, NPEP, NMAP and NPRO. The synthesis and preliminary results for the mutagenic effect of NMAP on the reversion of Salmonella typhimurium strains TA100 and TA1535 in the Ames test are reported.

White LM,Gardner SF, Gurley BJ, Marx MA, Wang PL, Estes M. Pharmacokinetics and cardiovascular effects of ma-huang (Ephedra sinica) in normotensive adults. J Clin Pharmacol 1997 Feb;37(2):116-122.
Abstract: The purpose of this study was to evaluate heart rate and blood pressure responses to a commercially available source of ma-haung, a natural source of the sympathomimetic substance, ephedrine, and to evaluate the pharmacokinetic properties of the product in normotensive, healthy adults. On day 1, twelve study participants were monitored with an ambulatory blood pressure device between hours 7 and 20. On day 2, they ingested four capsules of powdered ma-huang at hours 8 and 17 while again wearing the monitor between hours 7 and 20. Serial plasma samples were obtained and concentrations of ephedrine were analyzed by high- performance liquid chromatography. Pharmacokinetic parameters of ephedrine were determined from plasma concentration-time profiles. The ephedrine alkaloid content of each capsule was also determined by high- performance liquid chromatography. Six participants experienced a statistically significant increase in heart rate, but the effects on blood pressure were variable. The half-life, volume of distribution, clearance, and maximum concentration in plasma of ephedrine in the ma- huang product were similar to values previously reported for a 20 mg, immediate-release ephedrine tablet. Values for the absorption rate were considerably lower and time to reach maximum concentration was longer for the capsules, compared with the standard tablet. Variability in alkaloid content of ephedrine was low and yielded a mean dose of ephedrine at 19.4 mg; pseudoephedrine at 4.9 mg; and methylephedrine at 1.2 mg for a four-capsule dose. In summary, ma-haung had variable effects on blood pressure and increased heart rate in healthy, normotensive adults. Pharmacokinetic parameters for ephedrine were in agreement with those previously reported; however, the absorption rate was much slower after ingestion of ma-huang.

Zhang JS, Tian Z, Lou ZC. [Quality evaluation of twelve species of Chinese Ephedra (ma huang)] Yao Hsueh Hsueh Pao1989;24(11):865-871. [Article in Chinese]
Abstract: The contents of six Ephedra alkaloids, namely ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine and methyl-pseudoephedrine, in 12 species of Chinese Ephedra collected in 24 districts were determined by high performance liquid chromatography (HPLC). Zorbax CN column (25 cm x 4.6 mm I.D.) was used and the temperature of column oven was 23-25 degrees C. Dibutylamine phosphate solution 0.0009 mol/L (pH 2.2) was used as the mobile phase at flow rates: 0.8 ml/min for the first 7 minutes, raised to 1.5 ml/min in 30 sec and maintained for 16 minutes. The alkaloids eluted were detected at wave-length 210 nm. The results showed that ephedrine and pseudoephedrine are the main components in these Ephedra herbs, but the contents of the six Ephedra alkaloids vary greatly with the plant species. The contents of total alkaloids are higher and ephedrine is the main component in samples derived from Ephedra sinica, E. equisetina, E. monosperma and E. intermedia var. tibetica; but in E. intermedia and E. lomatolepis, the content of pseudoephedrine is higher than that of ephedrine. Methylephedrine content is higher in E. intermedia var. tibetica produced in Xizang (Tibet) and in E. sinica produced in north-eastern China than that in other species. The results also showed that the samples derived from E. przewalskii and E. lepidosperma contain so little alkaloids (less than 0.1%) that they are considered not suitable to be used as the drug Ma Huang. It is of interest that the cultivated Ephedra sinica showed lower alkaloids content compared with that growing wild.