Ephedrine hydrochloride
[CAS# 50-98-6]

Identification

• Classification: API >> Respiratory medication >> Asthma
• Name: Ephedrine hydrochloride
• Synonyms: (1R,2S)-(-)-Ephedrine hydrochloride; (-)-2-Methylamino-1-phenyl-propane-1-ol hydrochloride; alpha-[1-(Methylamino)ethyl]benzyl alcohol hydrochloride
• Molecular Formula: C₁₀H₁₅NO.HCl
• Molecular Weight: 201.69
• CAS Registry Number: 50-98-6
• EC Number: 200-074-6
• SMILES: C[C@@H]([C@@H](C1=CC=CC=C1)O)NC.Cl

Properties

• Solubility: 10mM (H2O)
• Melting point: 217-220 °C
• alpha: -34 ° (c=4, H2O)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302
• Safety Statements: P264-P270-P301+P317-P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Reproductive toxicity	Lact.	-	H362
Specific target organ toxicity - single exposure	STOT SE	2	H371
Reproductive toxicity	Repr.	1B	H360

Discovery and Applications

Ephedrine was first isolated from the ephedra plant in 1885 by Japanese chemist Nagai Nagayoshi. The hydrochloride form, C10H15NO·HCl, was later developed to improve its stability and solubility for pharmaceutical use. Structurally, ephedrine hydrochloride includes a benzene ring with hydroxyl (-OH) and amino (-NH2) groups on the side chains, which produce physiological effects.

Ephedrine hydrochloride is widely used for its bronchodilator and vasoconstrictor effects. It acts as a sympathomimetic, stimulating the sympathetic nervous system to increase the release of norepinephrine, which helps treat respiratory diseases. Ephedrine hydrochloride effectively relieves symptoms of asthma, bronchitis, and other respiratory diseases by relaxing bronchial muscles and dilating airways.

It is also used to combat hypotension. In anesthesia, it is used to control hypotension by constricting blood vessels and increasing cardiac output, ensuring stable blood flow during surgery.

Ephedrine hydrochloride stimulates alpha and beta adrenergic receptors by mimicking the effects of endogenous catecholamines. This causes bronchodilation, increased heart rate, and vasoconstriction. Its ability to cross the blood-brain barrier also helps to mildly stimulate the central nervous system, increasing alertness and energy levels.

Ephedrine hydrochloride is available in oral, injectable, and inhaled forms and is typically administered in doses of 15-60 mg every 4 to 6 hours to achieve decongestive and bronchodilatory effects. In emergency medicine, it can be given intravenously in small doses to rapidly raise blood pressure during acute hypotensive episodes.

Despite its medical benefits, ephedrine hydrochloride is strictly regulated due to its abuse in the production of methamphetamine and its stimulant effects, which can lead to dependence and adverse cardiovascular consequences. It is classified as a controlled substance in many countries, and sales are monitored and restricted to prevent abuse.

Potential side effects of ephedrine hydrochloride include increased heart rate, palpitations, hypertension, and insomnia. It is contraindicated in people with cardiovascular disease, hyperthyroidism, and those taking monoamine oxidase inhibitors (MAOIs).

References

1991. Thermogenic synergism between ephedrine and caffeine in healthy volunteers: A double-blind, placebo-controlled study. Metabolism: clinical and experimental, 40(3).
DOI: 10.1016/0026-0495(91)90117-f

1984. High-performance liquid chromatographic separation of the enantiomers of anti-inflammatory 2-arylpropionates: suitability of the method for in vitro metabolic studies. Journal of Chromatography A, 310.
DOI: 10.1016/s0021-9673(01)97855-0

1972. Quantum mechanical study of the conformational properties of phenethylamines of biochemical and medicinal interest. Journal of Medicinal Chemistry, 15(1).
DOI: 10.1021/jm00271a006