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Pronunciation | /ɪˈfɛdrɪn/ or /ˈɛfɪdriːn/ |
Trade names | Akovaz, Corphedra, Emerphed, others |
Other names | (−)-Ephedrine; (1R,2S)-Ephedrine; (1R,2S)-β-Hydroxy-N-methylamphetamine; (1R,2S)-β-Hydroxy-N-methyl-α-methyl-β-phenethylamine |
AHFS/Drugs.com | Ephedrine: Monograph HCl: Monograph Sulfate: Monograph |
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Routes of administration | By mouth, intravenous (IV), intramuscular (IM), subcutaneous (SC) |
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Bioavailability | 88% [6] |
Protein binding | ~24–29% (5–10% to albumin) [7] [8] [9] |
Metabolism | Largely unmetabolized [6] [10] |
Metabolites | • Norephedrine [6] [10] |
Onset of action | Oral: 15–60 minutes [11] IM : 10–20 minutes [11] IV : Rapid [11] |
Elimination half-life | 6 hours [6] |
Duration of action | Oral: 2–4 hours IV/IM: 60 minutes |
Excretion | Mainly urine (60% unchanged) [6] |
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ECHA InfoCard | 100.005.528 |
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Formula | C10H15NO |
Molar mass | 165.236 g·mol−1 |
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Ephedrine is a central nervous system (CNS) stimulant and sympathomimetic agent that is often used to prevent low blood pressure during anesthesia. [11] It has also been used for asthma, narcolepsy, and obesity but is not the preferred treatment. [11] It is of unclear benefit in nasal congestion. [11] It can be taken by mouth or by injection into a muscle, vein, or just under the skin. [11] Onset with intravenous use is fast, while injection into a muscle can take 20 minutes, and by mouth can take an hour for effect. [11] When given by injection, it lasts about an hour, and when taken by mouth, it can last up to four hours. [11]
Common side effects include trouble sleeping, anxiety, headache, hallucinations, high blood pressure, fast heart rate, loss of appetite, and urinary retention. [11] Serious side effects include stroke and heart attack. [11] While likely safe in pregnancy, its use in this population is poorly studied. [12] [13] Use during breastfeeding is not recommended. [13] Ephedrine works by inducing the release of norepinephrine and hence indirectly activating the α- and β-adrenergic receptors. [11] Chemically, ephedrine is a substituted amphetamine and is the (1R,2S)-enantiomer of β-hydroxy-N-methylamphetamine. [14]
Ephedrine was first isolated in 1885 and came into commercial use in 1926. [15] [16] It is on the World Health Organization's List of Essential Medicines. [17] It is available as a generic medication. [11] It can normally be found in plants of the Ephedra genus. [11] [18] Over-the-counter dietary supplements containing ephedrine are illegal in the United States, [11] with the exception of those used in traditional Chinese medicine, where its presence is noted by má huáng. [11] [18]
Ephedrine is a non-catecholamine sympathomimetic with cardiovascular effects similar to those of adrenaline/epinephrine: increased blood pressure, heart rate, and contractility. Like pseudoephedrine it is a bronchodilator, with pseudoephedrine having considerably less effect. [19] [20]
Ephedrine may decrease motion sickness, but it has mainly been used to decrease the sedating effects of other medications used for motion sickness. [21] [22]
Ephedrine is also found to have quick and long-lasting responsiveness in congenital myasthenic syndrome in early childhood and also even in adults with a novel COLQ mutation. [23]
Ephedrine is administered by intravenous boluses. Redosing usually requires increased doses to offset the development of tachyphylaxis, which is attributed to the depletion of catecholamine stores. [19]
Ephedrine promotes modest short-term weight loss, [24] specifically fat loss, but its long-term effects are unknown. [25] In mice, ephedrine is known to stimulate thermogenesis in the brown adipose tissue, but because adult humans have only small amounts of brown fat, thermogenesis is assumed to take place mostly in the skeletal muscle. Ephedrine also decreases gastric emptying. Methylxanthines such as caffeine and theophylline have a synergistic effect with ephedrine for weight loss. This led to the creation and marketing of compound products. [26] One of them, known as the ECA stack, contains ephedrine with caffeine and aspirin. It is a popular supplement taken by bodybuilders seeking to cut body fat before a competition. [27] A 2021 systematic review found that ephedrine led to a 2 kilograms (4.4 lb) weight loss greater than placebo, raised heart rate, and reduced LDL and raised HDL, with no statistically significant difference in blood pressure. [28]
Ephedrine is available as a prescription-only pharmaceutical drug in the form of an intravenous solution, under brand names including Akovaz, Corphedra, Emerphed, and Rezipres as well as in generic forms, in the United States. [29] [30] It is also available over-the-counter in the form of 12.5 and 25 mg oral tablets for use as a bronchodilator and as a 0.5% concentration nasal spray for use as a decongestant. [30] The drug is additionally available in combination with guaifenesin in the form of oral tablets and liquids. [30] Ephedrine is provided as the hydrochloride or sulfate salt in pharmaceutical formulations. [29] [30]
Ephedrine should not be used in conjunction with certain antidepressants, namely norepinephrine-dopamine reuptake inhibitors (NDRIs), as this increases the risk of symptoms due to excessive serum levels of norepinephrine.
Bupropion is an example of an antidepressant with an amphetamine-like structure similar to ephedrine, and it is an NDRI. Its action bears more resemblance to amphetamine than to fluoxetine in that its primary mode of therapeutic action involves norepinephrine and to a lesser degree dopamine, but it also releases some serotonin from presynaptic clefts. It should not be used with ephedrine, as it may increase the likelihood of side effects.
Ephedrine should be used with caution in patients with inadequate fluid replacement, impaired adrenal function, hypoxia, hypercapnia, acidosis, hypertension, hyperthyroidism, prostatic hypertrophy, diabetes mellitus, cardiovascular disease, during delivery if maternal blood pressure is >130/80 mmHg, and during lactation. [31]
Contraindications for the use of ephedrine include: closed-angle glaucoma, phaeochromocytoma, asymmetric septal hypertrophy (idiopathic hypertrophic subaortic stenosis), concomitant or recent (previous 14 days) monoamine oxidase inhibitor (MAOI) therapy, general anaesthesia with halogenated hydrocarbons (particularly halothane), tachyarrhythmias or ventricular fibrillation, or hypersensitivity to ephedrine or other stimulants.[ citation needed ]
Ephedrine should not be used at any time during pregnancy unless specifically indicated by a qualified physician and only when other options are unavailable. [31]
Ephedrine is a potentially dangerous natural compound; as of 2004 [update] the US Food and Drug Administration had received over 18,000 reports of adverse effects in people using it. [32]
Adverse drug reactions (ADRs) are more common with systemic administration (e.g. injection or oral administration) compared to topical administration (e.g. nasal instillations). ADRs associated with ephedrine therapy include [33]
Overdose of ephedrine may result in sympathomimetic symptoms like tachycardia and hypertension.[ citation needed ]
Ephedrine with monoamine oxidase inhibitors (MAOIs) like phenelzine and tranylcypromine can result in hypertensive crisis.[ citation needed ]
Compound | NE | DA | 5-HT | Ref | ||
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Dextroamphetamine (S(+)-amphetamine) | 6.6–7.2 | 5.8–24.8 | 698–1765 | [36] [37] | ||
S(–)-Cathinone | 12.4 | 18.5 | 2366 | [38] | ||
Ephedrine ((–)-ephedrine) | 43.1–72.4 | 236–1350 | >10000 | [36] | ||
(+)-Ephedrine | 218 | 2104 | >10000 | [36] [38] | ||
Dextromethamphetamine (S(+)-methamphetamine) | 12.3–13.8 | 8.5–24.5 | 736–1291.7 | [36] [39] | ||
Levomethamphetamine (R(–)-methamphetamine) | 28.5 | 416 | 4640 | [36] | ||
(+)-Phenylpropanolamine ((+)-norephedrine) | 42.1 | 302 | >10000 | [38] | ||
(–)-Phenylpropanolamine ((–)-norephedrine) | 137 | 1371 | >10000 | [38] | ||
Cathine ((+)-norpseudoephedrine) | 15.0 | 68.3 | >10000 | [38] | ||
(–)-Norpseudoephedrine | 30.1 | 294 | >10000 | [38] | ||
(–)-Pseudoephedrine | 4092 | 9125 | >10000 | [38] | ||
Pseudoephedrine ((+)-pseudoephedrine) | 224 | 1988 | >10000 | [38] | ||
Notes: The smaller the value, the more strongly the substance releases the neurotransmitter. See also Monoamine releasing agent § Activity profiles for a larger table with more compounds. | ||||||
Ephedrine, a sympathomimetic amine, acts on part of the sympathetic nervous system (SNS). The principal mechanism of action relies on its indirect stimulation of the adrenergic receptor system by increasing activation of α- and β-adrenergic receptors via induction of norepinephrine release. [40] The presence of direct interactions with α-adrenergic receptors is unlikely but still controversial. [41] [20] [42] [43] L-ephedrine, and particularly its stereoisomer norpseudoephedrine (which is also present in Catha edulis ) has indirect sympathomimetic effects and due to its ability to cross the blood–brain barrier, it is a CNS stimulant similar to amphetamines, but less pronounced, as it releases norepinephrine and dopamine in the brain. [44]
The oral bioavailability of ephedrine is 88%. [6] The onset of action of ephedrine orally is 15 to 60 minutes, via intramuscular injection is 10 to 20 minutes, and via intravenous infusion is within seconds. [11]
Its plasma protein binding is approximately 24 to 29%, with 5 to 10% bound to albumin. [7] [8] [9]
Ephedrine is largely not metabolized. [6] Norephedrine (phenylpropanolamine) is an active metabolite of ephedrine formed via N-demethylation. [6] [10] About 8 to 20% of an oral dose of ephedrine is demethylated into norephedrine, about 4 to 13% is oxidatively deaminated into benzoic acid, and a small fraction is converted into 1,2-dihydroxy-1-phenylpropane. [10]
Ephedrine is eliminated mainly in urine, with 60% (range 53–79%) excreted unchanged. [6] [10]
The elimination half-life of ephedrine is 6 hours. [6] Its duration of action orally is 2 to 4 hours and via intravenous or intramuscular injection is 60 minutes.[ citation needed ]
The elimination of ephedrine is dependent on urinary pH. [10]
Ephedrine, or (−)-(1R,2S)-ephedrine, also known as (1R,2S)-β-hydroxy-N-methyl-α-methyl-β-phenethylamine or as (1R,2S)-β-hydroxy-N-methylamphetamine, is a substituted phenethylamine and amphetamine derivative. It is similar in chemical structure to phenylpropanolamine, methamphetamine, and epinephrine (adrenaline). It differs from methamphetamine only by the presence of a hydroxyl group (–OH). Chemically, ephedrine is an alkaloid with a phenethylamine skeleton found in various plants in the genus Ephedra (family Ephedraceae). It is most usually marketed as the hydrochloride or sulfate salt. [45]
It has an experimental log P of 1.13, while its predicted log P values range from 0.9 to 1.32. [14] [6] [46] The lipophilicity of amphetamines is closely related to their brain permeability. [47] For comparison to ephedrine, the experimental log P of methamphetamine is 2.1, [48] of amphetamine is 1.8, [49] [48] of pseudoephedrine is 0.89, [50] of phenylpropanolamine is 0.7, [51] of phenylephrine is -0.3, [52] and of norepinephrine is -1.2. [53] Methamphetamine has high brain permeability, [48] whereas phenylephrine and norepinephrine are peripherally selective drugs. [54] [55] The optimal log P for brain permeation and central activity is about 2.1 (range 1.5–2.7). [56]
Ephedrine hydrochloride has a melting point of 187−188 °C. [57]
The racemic form of ephedrine is racephedrine ((±)-ephedrine; dl-ephedrine; (1RS,2SR)-ephedrine). [58] A stereoisomer of ephedrine is pseudoephedrine. [58] Derivatives of ephedrine include methylephedrine (N-methylephedrine), etafedrine (N-ethylephedrine), cinnamedrine (N-cinnamylephedrine), and oxilofrine (4-hydroxyephedrine). [58] Analogues of ephedrine include phenylpropanolamine (norephedrine) and metaraminol (3-hydroxynorephedrine). [58]
The presence of an N-methyl group decreases binding affinities at α-adrenergic receptors, compared with norephedrine. Ephedrine, though, binds better than N-methylephedrine, which has an additional methyl group at the nitrogen atom. Also, the steric orientation of the hydroxyl group is important for receptor binding and functional activity. [42]
Ephedrine exhibits optical isomerism and has two chiral centres, giving rise to four stereoisomers. By convention, the pair of enantiomers with the stereochemistry (1R,2S) and (1S,2R) is designated ephedrine, while the pair of enantiomers with the stereochemistry (1R,2R) and (1S,2S) is called pseudoephedrine.
The isomer which is marketed is (−)-(1R,2S)-ephedrine. [59]
In the outdated D/L system (+)-ephedrine is also referred to as D-ephedrine and (−)-ephedrine as L-ephedrine (in which case, in the Fisher projection, the phenyl ring is drawn at the bottom). [59] [60]
Often, the D/L system (with small caps) and the d/l system (with lower-case) are confused. The result is that the levorotary l-ephedrine is wrongly named L-ephedrine and the dextrorotary d-pseudoephedrine (the diastereomer) wrongly D-pseudoephedrine.
The IUPAC names of the two enantiomers are (1R,2S)- respectively (1S,2R)-2-methylamino-1-phenylpropan-1-ol. A synonym is erythro-ephedrine.
Ephedrine may be quantified in blood, plasma, or urine to monitor possible abuse by athletes, confirm a diagnosis of poisoning, or assist in a medicolegal death investigation. Many commercial immunoassay screening tests directed at the amphetamines cross-react appreciably with ephedrine, but chromatographic techniques can easily distinguish ephedrine from other phenethylamine derivatives. Blood or plasma ephedrine concentrations are typically in the 20–200 μg/L range in persons taking the drug therapeutically, 300–3000 μg/L in abusers or poisoned patients, and 3–20 mg/L in cases of acute fatal overdosage. The current World Anti-Doping Agency (WADA) limit for ephedrine in an athlete's urine is 10 μg/mL. [61] [62] [63] [64]
Ephedrine in its natural form, known as máhuáng (麻黄) in traditional Chinese medicine, has been documented in China since the Han dynasty (206 BC – 220 AD) as an antiasthmatic and stimulant. [65] In traditional Chinese medicine, máhuáng has been used as a treatment for asthma and bronchitis for centuries. [66]
In 1885, the chemical synthesis of ephedrine was first accomplished by Japanese organic chemist Nagai Nagayoshi based on his research on traditional Japanese and Chinese herbal medicines.
The industrial manufacture of ephedrine in China began in the 1920s, when Merck began marketing and selling the drug as ephetonin. Ephedrine exports from China to the West grew from 4 to 216 tonnes between 1926 and 1928. [67]
Ephedrine was first introduced for medical use in the United States in 1926. [32]
It was introduced in 1948 in Vicks Vatronol nose drops (now discontinued) which contained ephedrine sulfate as the active ingredient for rapid nasal decongestion.
Ephedrine is the generic name of the drug and its BAN . [58] [45] [68] Its DCF is ephédrine while its DCIT is efedrina. [45] [68] In the case of the hydrochloride salt, its generic name is ephedrine hydrochloride and this is its USAN , BANM , and JAN . [58] [45] [68] In the case of the sulfate salt, its generic name is ephedrine sulfate or ephedrine sulphate and the former is its USAN while the latter is its BANM . [58] [45] [68] A synonym of ephedrine sulfate is isofedrol. [58] These names all refer to the (1R,2R)-enantiomer of ephedrine. [58] [45] The racemic form of ephedrine is known as racephedrine and this is its INN and BAN , while the hydrochloride salt of the racemic form is racephedrine hydrochloride and this is its USAN . [69]
As a phenethylamine, ephedrine has a similar chemical structure to amphetamines and is a methamphetamine analog having the methamphetamine structure with a hydroxyl group at the β position. Because of ephedrine's structural similarity to methamphetamine, it can be used to create methamphetamine using chemical reduction in which ephedrine's hydroxyl group is removed; this has made ephedrine a highly sought-after chemical precursor in the illicit manufacture of methamphetamine.
The most popular method for reducing ephedrine to methamphetamine is similar to the Birch reduction, in that it uses anhydrous ammonia and lithium metal in the reaction. The second-most popular method uses red phosphorus and iodine in the reaction with ephedrine. Moreover, ephedrine can be synthesized into methcathinone via simple oxidation. As such, ephedrine is listed as a table-I precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances . [70]
Ephedrine has been used as a performance-enhancing drug in exercise and sports. [41] [71] [72] [73] It can increase heart rate, blood pressure, and cardiac contractility as well as act as a psychostimulant. [41] Ephedrine is often used in combination with caffeine for performance-enhancing purposes. [72] [73]
In chemical synthesis, ephedrine is used in bulk quantities as a chiral auxiliary group. [74]
In saquinavir synthesis, the half-acid is resolved as its salt with l-ephedrine.
In January 2002, Health Canada issued a voluntary recall of all ephedrine products containing more than 8 mg per dose, all combinations of ephedrine with other stimulants such as caffeine, and all ephedrine products marketed for weight-loss or bodybuilding indications, citing a serious risk to health. [75] Ephedrine is still sold as an oral nasal decongestant [76] in 8 mg pills as a natural health product, with a limit of 0.4 g (400 mg) per package, the limit established by the Controlled Drugs and Substances Act as it is considered as Class A Precursor. [77]
In 1997, the FDA proposed a regulation on ephedra (the herb from which ephedrine is obtained), which limited an ephedra dose to 8 mg (of active ephedrine) with no more than 24 mg per day. [78] This proposed rule was withdrawn, in part, in 2000 because of "concerns regarding the agency's basis for proposing a certain dietary ingredient level and a duration of use limit for these products." [79] In 2004, the FDA created a ban on ephedrine alkaloids marketed for reasons other than asthma, colds, allergies, other disease, or traditional Asian use. [80] On April 14, 2005, the U.S. District Court for the District of Utah ruled the FDA did not have proper evidence that low dosages of ephedrine alkaloids are actually unsafe, [81] but on August 17, 2006, the U.S. Court of Appeals for the Tenth Circuit in Denver upheld the FDA's final rule declaring all dietary supplements containing ephedrine alkaloids adulterated, and therefore illegal for marketing in the United States. [82] Furthermore, ephedrine is banned by the NCAA, MLB, NFL, and PGA. [83] Ephedrine is, however, still legal in many applications outside of dietary supplements. Purchasing is currently limited and monitored, with specifics varying from state to state.
The House passed the Combat Methamphetamine Epidemic Act of 2005 as an amendment to the renewal of the USA PATRIOT Act. Signed into law by President George W. Bush on March 6, 2006, the act amended the US Code (21 USC 830) concerning the sale of products containing ephedrine and the closely related drug pseudoephedrine. Both substances are used as precursors in the illicit production of methamphetamine, and to discourage that use the federal statute included the following requirements for merchants who sell these products:
The law gives similar regulations to mail-order purchases, except the monthly sales limit is 7.5 g.
As a pure herb or tea, má huáng, containing ephedrine, is still sold legally in the US. The law restricts/prohibits its being sold as a dietary supplement (pill) or as an ingredient/additive to other products, like diet pills.
Ephedrine and all Ephedra species that contain it are considered Schedule 4 substances under the Poisons Standard. A Schedule 4 drug is considered a Prescription Only Medicine, or Prescription Animal Remedy – Substances, the use or supply of which should be by or on the order of persons permitted by State or Territory legislation to prescribe and should be available from a pharmacist on prescription under the Poisons Standard.
In South Africa, ephedrine was moved to schedule 6 on 27 May 2008, [84] which makes pure ephedrine tablets prescription only. Pills containing ephedrine up to 30mg per tablet in combination with other medications are still available OTC, schedule 1 and 2, for sinus, head colds, and influenza.
Ephedrine was freely available in pharmacies in Germany until 2001. Afterward, access was restricted since it was mostly bought for unindicated uses. Similarly, ephedra can only be bought with a prescription. Since April 2006, all products, including plant parts, that contain ephedrine are only available with a prescription. [85]
Ephedrine is obtained from the plant Ephedra sinica and other members of the genus Ephedra, from which the name of the substance is derived. Raw materials for the manufacture of ephedrine and traditional Chinese medicines are produced in China on a large scale. As of 2007, companies produced for export US$13 million worth of ephedrine from 30,000 tons of ephedra annually, or about ten times the amount used in traditional Chinese medicine. [86]
Most of the l-ephedrine produced today for official medical use is made synthetically as the extraction and isolation process from E. sinica is tedious and no longer cost-effective. [87] [ unreliable source? ]
Ephedrine was long thought to come from modifying the amino acid L-phenylalanine. [90] L-Phenylalanine would be decarboxylated and subsequently attacked with ω-aminoacetophenone. Methylation of this product would then produce ephedrine. This pathway has since been disproven. [90] A new pathway proposed suggests that phenylalanine first forms cinnamoyl-CoA via the enzymes phenylalanine ammonia-lyase and acyl CoA ligase. [88] The cinnamoyl-CoA is then reacted with a hydratase to attach the alcohol functional group. The product is then reacted with a retro-aldolase, forming benzaldehyde. Benzaldehyde reacts with pyruvic acid to attach a 2-carbon unit. This product then undergoes transamination and methylation to form ephedrine and its stereoisomer, pseudoephedrine. [89]
Stimulants are a class of drugs that increase the activity of the brain. They are used for various purposes, such as enhancing alertness, attention, motivation, cognition, mood, and physical performance. Some of the most common stimulants are caffeine, nicotine, amphetamines, cocaine, methylphenidate, and modafinil.
Pseudoephedrine, sold under the brand name Sudafed among others, is a sympathomimetic medication which is used as a decongestant to treat nasal congestion. It has also been used off-label for certain other indications, like treatment of low blood pressure. At higher doses, it may produce various additional effects including stimulant, appetite suppressant, and performance-enhancing effects. In relation to this, non-medical use of pseudoephedrine has been encountered. The medication is taken by mouth.
Ephedra is a medicinal preparation from the plant Ephedra sinica. Several additional species belonging to the genus Ephedra have traditionally been used for a variety of medicinal purposes, and are a possible candidate for the soma plant of Indo-Iranian religion. It has been used in traditional Chinese medicine, in which it is referred to as Ma Huang, for more than 2,000 years. Native Americans and Mormon pioneers drank a tea brewed from other Ephedra species, called "Mormon tea" and "Indian tea".
Methcathinone is a monoamine alkaloid and psychoactive stimulant, a substituted cathinone. It is used as a recreational drug due to its potent stimulant and euphoric effects and is considered to be addictive, with both physical and psychological withdrawal occurring if its use is discontinued after prolonged or high-dosage administration. It is usually snorted, but can be smoked, injected, or taken orally.
D-norpseudoephedrine, also known as cathine and (+)-norpseudoephedrine, is a psychoactive drug of the phenethylamine and amphetamine chemical classes which acts as a stimulant. Along with cathinone, it is found naturally in Catha edulis (khat), and contributes to its overall effects. It has approximately 7-10% the potency of amphetamine.
Clandestine chemistry is chemistry carried out in secret, and particularly in illegal drug laboratories. Larger labs are usually run by gangs or organized crime intending to produce for distribution on the black market. Smaller labs can be run by individual chemists working clandestinely in order to synthesize smaller amounts of controlled substances or simply out of a hobbyist interest in chemistry, often because of the difficulty in ascertaining the purity of other, illegally synthesized drugs obtained on the black market. The term clandestine lab is generally used in any situation involving the production of illicit compounds, regardless of whether the facilities being used qualify as a true laboratory.
Phenylpropanolamine (PPA), sold under many brand names, is a sympathomimetic agent which is used as a decongestant and appetite suppressant. It was previously commonly used in prescription and over-the-counter cough and cold preparations. The medication is taken by mouth.
Sympathomimetic drugs are stimulant compounds which mimic the effects of endogenous agonists of the sympathetic nervous system. Examples of sympathomimetic effects include increases in heart rate, force of cardiac contraction, and blood pressure. The primary endogenous agonists of the sympathetic nervous system are the catecholamines, which function as both neurotransmitters and hormones. Sympathomimetic drugs are used to treat cardiac arrest and low blood pressure, or even delay premature labor, among other things.
Phenylephrine, sold under the brand names Neosynephrine and Sudafed PE among others, is a medication used as a decongestant for uncomplicated nasal congestion in the form of a nasal spray or oral tablet, to dilate the pupil, to increase blood pressure given intravenously in cases of low blood pressure, and to relieve hemorrhoids as a suppository. It can also be applied to the skin.
The ECA stack is a drug combination used in weight loss and as a stimulant. ECA is an initialism for ephedrine, caffeine, and aspirin, with variants of it including the EC stack, which removes the aspirin for those who can not tolerate it. Dietary supplements based on or including elements of ECA were popular through the 1990s and early 2000s, but the marketing of ephedra- or ephedrine-containing stimulant combinations for weight loss and bodybuilding is now restricted or illegal in the United States and the Netherlands due to reports of heart attack, stroke, and death associated with these supplements.
Levmetamfetamine, also known as l-desoxyephedrine or levomethamphetamine, and commonly sold under the brand name Vicks VapoInhaler among others, is an optical isomer of methamphetamine primarily used as a topical nasal decongestant. It is used to treat nasal congestion from allergies and the common cold. It was first used medically as decongestant beginning in 1958 and has been used for such purposes, primarily in the United States, since then.
A cardiac stimulant is a drug which acts as a stimulant of the heart – e.g., via positive chronotropic action and/or inotropic action. They increase cardiac output.
Levoamphetamine is a stimulant medication which is used in the treatment of certain medical conditions. It was previously marketed by itself under the brand name Cydril, but is now available only in combination with dextroamphetamine in varying ratios under brand names like Adderall and Evekeo. The drug is known to increase wakefulness and concentration in association with decreased appetite and fatigue. Pharmaceuticals that contain levoamphetamine are currently indicated and prescribed for the treatment of attention deficit hyperactivity disorder (ADHD), obesity, and narcolepsy in some countries. Levoamphetamine is taken by mouth.
A norepinephrine releasing agent (NRA), also known as an adrenergic releasing agent, is a catecholaminergic type of drug that induces the release of norepinephrine (noradrenaline) and epinephrine (adrenaline) from the pre-synaptic neuron into the synapse. This in turn leads to increased extracellular concentrations of norepinephrine and epinephrine therefore an increase in adrenergic neurotransmission.
Substituted amphetamines, or simply amphetamines, are a class of compounds based upon the amphetamine structure; it includes all derivative compounds which are formed by replacing, or substituting, one or more hydrogen atoms in the amphetamine core structure with substituents. The compounds in this class span a variety of pharmacological subclasses, including stimulants, empathogens, and hallucinogens, among others. Examples of substituted amphetamines are amphetamine (itself), methamphetamine, ephedrine, cathinone, phentermine, mephentermine, tranylcypromine, bupropion, methoxyphenamine, selegiline, amfepramone (diethylpropion), pyrovalerone, MDMA (ecstasy), and DOM (STP).
Oxilofrine, sold under the brand names Carnigen and Suprifen among others, is a sympathomimetic medication which has been used as an antihypotensive agent and cough suppressant. It is taken by mouth.
Methylephedrine, sold under the brand name Metheph among others, is a sympathomimetic medication described as an antiasthmatic agent and used to treat coughing and nasal congestion. It is reported to be used in various over-the-counter cough and cold preparations throughout the world, including Japan.
Amphetamine and methamphetamine are central nervous system stimulants used to treat a variety of conditions. When used recreationally, they are colloquially known as "speed" or sometimes "crank". Amphetamine was first synthesized in 1887 in Germany by Romanian chemist Lazăr Edeleanu, who named it phenylisopropylamine. Around the same time, Japanese organic chemist Nagai Nagayoshi isolated ephedrine from the Chinese ephedra plant and later developed a method for ephedrine synthesis. Methamphetamine was synthesized from ephedrine in 1893 by Nagayoshi. Neither drug had a pharmacological use until 1934, when Smith, Kline & French began selling amphetamine as an inhaler under the trade name Benzedrine for congestion.
Amphetamine type stimulants (ATS) are a group of synthetic drugs that are chemical derivatives of the parent compound alpha-methylphenethylamine, also known as amphetamine. Common ATS includes amphetamine, methamphetamine, ephedrine, pseudoephedrine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxyethylamphetamine (MDEA). ATS when used illicitly has street names including ice, meth, crystal, crank, bennies, and speed. Within the group of amphetamine-type stimulants, there are also prescription drugs including mixed amphetamine salts, dextroamphetamine, and lisdexamfetamine.
Substituted β-hydroxyamphetamines, or simply β-hydroxyamphetamines, also known as phenylisopropanolamines, phenylpropanolamines, norephedrines, or cathinols, are derivatives of β-hydroxyamphetamine with one or more chemical substituents. They are substituted phenethylamines, phenylethanolamines (β-hydroxyphenethylamines), and amphetamines (α-methylphenethylamines), and are closely related to but distinct from the substituted cathinones (β-ketoamphetamines). Examples of β-hydroxyamphetamines include the β-hydroxyamphetamine stereoisomers phenylpropanolamine and cathine and the stereospecific N-methylated β-hydroxyamphetamine derivatives ephedrine and pseudoephedrine, among many others.
Metamfetamine acts in a manner similar to amfetamine, but with the addition of the methyl group to the chemical structure. It is more lipophilic (Log p value 2.07, compared with 1.76 for amfetamine),4 thereby enabling rapid and extensive transport across the blood–brain barrier.19
Lipophilicity was the first of the descriptors to be identified as important for CNS penetration. Hansch and Leo54 reasoned that highly lipophilic molecules will be partitioned into the lipid interior of membranes and will be retained there. However, ClogP correlates nicely with LogBBB with increasing lipophilicity and increasing brain penetration. For several classes of CNS active substances, Hansch and Leo54 found that blood-brain barrier penetration is optimal when the LogP values are in the range of 1.5-2.7, with a mean value of 2.1. An analysis of small drug-like molecules suggested that for better brain permeation46 and for good intestinal permeability55 the LogD values need to be greater than 0 and less than 3. In comparison, the mean value for ClogP for the marketed CNS drugs is 2.5, which is in good agreement with the range found by Hansch et al.22
Defendants-appellants, 459 F.3d 1033 (10th Cir. 2006)