Ephedrine, also known as ephedrine, is an alkaloid with the chemical formula CtenHfifteenNO，Listed as Class I precursor chemicals[2]。
Ephedrine is clinically used for: ① prevention of bronchial asthma attack and alleviation of mild asthma attack, but not effective for acute severe asthma attack. ②Treat hypotension and chronic hypotension caused by subarachnoid anesthesia or epidural anesthesia. ③Treat nasal congestion caused by congestion and swelling of nasal mucosa.
Solubility: soluble in water, easily soluble in ethanol, ether, chloroform
Calculate chemical data
Reference value for drainage parameter calculation (XlogP): 0.9
Number of hydrogen bond donors: 2
Number of hydrogen bond receptors: 2
Number of rotatable chemical bonds: 3
Number of tautomers:
Topological molecular polar surface area (TPSA): 32.3
Number of heavy atoms: 12
Surface charge: 0
Complexity: 121
Number of isotope atoms: 0
Determine the number of atomic structure centers: 2
Number of uncertain atomic structure centers: 0
Determine the number of chemical bond structure centers: 0
Number of uncertain chemical bond structure centers: 0
Number of covalent bond units: 1
security information
Customs code: 2939490090
Hazard category code: R22
Safety instruction: S22;S25
purpose
Ephedrine is an adrenergic drug.It can excite sympathetic nerve, and its effect is longer than adrenaline;It can relax bronchial smooth muscle and contract blood vessels;It has significant central excitatory effect.It is mainly used in the treatment of habitual bronchial asthma and the prevention of asthma attacks in clinic. It is less effective than epinephrine in the treatment of severe bronchial asthma, but it is better than epinephrine in the treatment of nasal congestion and nasal congestion.
Pharmacopoeia standard
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identify
1. Take about 10mg of this product, add 1mL of water to dissolve it, add 2 drops of copper sulfate test solution and 1mL of 20% sodium hydroxide solution, and it will turn blue and purple;Add 1mL of ether, shake it and place it. The ether layer will turn purple red and the water layer will turn blue.
2. The infrared absorption spectrum of this product should be consistent with the control spectrum (spectrum set 387 figure).
3. Identification reaction of chlorides in the aqueous solution of this product (Appendix III).
inspect
Clarity of solution
Take 1.0g of this product, add 20mL of water to dissolve it, and the solution should be clear.
PH
Take 1.0g of this product, add 20mL of water to dissolve it, add 1 drop of methyl red indicator solution, if it turns yellow, add 0.10mL of sulfuric acid titrant (0.01mol/L), and it will turn red;If it turns light red, add 0.10ml of sodium hydroxide titrant (0.02mol/L), and the strain will turn yellow.
sulfate
Take 1.0g of this product and check it according to the law (Appendix IIIB). Compared with the control solution made of 1.0mL of standard potassium sulfate solution, it should not be more concentrated (0.010%).
Related substances
Take about 50mg of this product, put it into a 50mL measuring flask, add mobile phase to dissolve it and dilute it to the scale, shake it well, and use it as the test solution;Accurately measure 1mL, put it into a 100mL measuring bottle, dissolve it with mobile phase, dilute it to the scale, shake it up, and use it as the reference solution.Test according to the high performance liquid chromatography (Appendix V D), and use octadecylsilyl bonded silica gel as the filler;Take phosphate buffer solution (6.8g of potassium dihydrogen phosphate, 5mL of triethylamine, 4mL of phosphoric acid, add water to 1000mL, adjust the pH value to 3.0 ± 0.1 with dilute phosphoric acid or triethylamine) - acetonitrile (90:10) as mobile phase;The detection wavelength is 210nm.The number of theoretical plates shall not be less than 3000 according to the peak of ephedrine hydrochloride.Take 10 μ L of the reference solution, inject it into the liquid chromatograph, and adjust the detection sensitivity so that the peak height of the main component chromatographic peak is about 20% of the full range;Then precisely measure 10 μ L each of the test solution and the reference solution, inject them into the liquid chromatograph respectively, and record the chromatogram to twice the retention time of the main component peak.If there are impurity peaks in the chromatogram of the test solution, the sum of the impurity peak areas shall not be greater than 0.5 times (0.5%) of the main peak area of the reference solution.
Loss on drying
Take the product, dry it at 105 ℃ to constant weight, and the weight loss shall not exceed 0.5% (Appendix VIII L).
Ignition residue
Not more than 0.1% (Appendix Ⅷ N).
heavy metal
Take 1.0g of this product, add 23mL of water to dissolve it, add 2mL of acetate buffer (pH=3.5), and check according to the law (Appendix VIII, Method 1, H). The content of heavy metals should not exceed 20 parts per million.
Assay
Take about 0.15g of this product, weigh it accurately, add 10mL of glacial acetic acid, heat it to dissolve, add 4mL of mercury acetate test solution and 1 drop of crystal violet indicator solution, titrate it with perchloric acid titrant (0.1mol/L) until the solution appears emerald green, and correct the titration result with blank test.Every 1mL perchloric acid titrant (0.1mol/L) is equivalent to 20.17mg CtenHfifteenNO‧HCl。[1]
category
β2 Adrenergic receptor agonists.
Storage
Sealed storage.
Drug description
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pharmacology
It can directly activate the adrenergic receptor, or indirectly activate the adrenergic receptor by stimulating the adrenergic nerve endings to release norepinephrineαandβThe receptors all have excitatory effects: ① cardiovascular system: make skin, mucosa and visceral blood vessels shrink, and reduce blood flow;Coronary and cerebral vessels dilated and blood flow increased.After medication, blood pressure and pulse pressure increased.The cardiac contractility and cardiac output increased.As the blood pressure rises, the vagus nerve is reflexively excited, so the heart rate is unchanged or slightly slow. ②Bronchus: relax bronchial smooth muscle;hisα-The effect can also make the bronchial mucosa vasoconstriction, reduce congestion and edema, and help to improve small airway obstruction.However, long-term application may lead to excessive contraction of mucosal blood vessels, increase of capillary pressure, and aggravation of congestion and edema.In addition,αThe effect can also aggravate the spasm of bronchial smooth muscle. ③Central nervous system: excites the cerebral cortex and subcortical center, producing mental excitement, insomnia, restlessness and tremor.After oral administration, it is easy to be absorbed from the intestine, and can enter the cerebrospinal fluid through the blood brain barrier.VdIt is 3~4L/kg. After absorption, only a small amount of deaminating and oxidation occurs, and 79% of it is excreted in urine in its original form.The effect is weaker and longer than adrenaline,t1/23~4 hours.
Pharmacokinetics
Oral administration can be absorbed quickly and enter cerebrospinal fluid through blood-brain barrier.It takes 15-60 minutes after oral administration and lasts for 3-5 hours.t1/2When the urine pH is 5, it lasts for about 3 hours, and when the urine pH is 6.3, it lasts for about 6 hours.After absorption, only a small amount of it is deaminated and oxidized, and most of it is discharged from urine in its original form。
indication
1. Prevention of bronchial asthma attack and alleviation of mild asthma attack are not effective for acute severe asthma attack.
2. It is used for hypotension and chronic hypotension caused by subarachnoid anesthesia or epidural anesthesia.
3. Treat nasal congestion caused by congestion and swelling of nasal mucosa.
Usage and dosage
Due to different dosage forms and specifications, please read the drug manual carefully or follow the doctor's advice.
Adverse reactions
A large amount of long-term use can cause adverse reactions such as tremor, anxiety, insomnia, headache, palpitations, fever, sweating, etc.When taking it at night, often take sedative hypnotics such as phenobarbital to prevent insomnia.
contraindication
It is forbidden for patients with hyperthyroidism, hypertension, arteriosclerosis, angina pectoris, etc.
matters needing attention
1. Cross allergic reaction: people who are allergic to other sympathomimetic amine drugs, such as adrenaline, isoproterenol, etc., are also allergic to this product.
2. In case of headache, anxiety, tachycardia, dizziness, hyperhidrosis and other symptoms, the drug should be stopped or the dosage should be adjusted.
3. Repeated use of the drug in a short period of time can gradually weaken the effect (rapid tolerance phenomenon), and it can recover after several hours of drug withdrawal.If the drug is administered no more than 3 times a day, the tolerance is not obvious.
Drugs for pregnant and lactating women
1. This product is used to maintain blood pressure during caesarean section anesthesia, which can accelerate the heartbeat of the fetus. It should not be used when the maternal blood pressure exceeds 17.3/10.7kPa (130/80mmHg).
2. This product can be secreted into milk, and is forbidden for lactating women.
Children's medication
Children, 0.5~1mg/kg each time, three times a day.
Medication for elderly patients
This product can cause high blood pressure, dysuria, and mental excitement. The elderly should use it with caution.
Drug interaction
1. Ephedrine is used in combination with barbiturates, diphenhydramine and aminophylline to inhibit, antiallergic, anticholinergic, relieve bronchospasm and reduce gland secretion through the central nervous system of the latter.
2. It should not be used together with monoamine oxidase inhibitors such as Youjiangning to avoid high blood pressure.
3. When used together with adrenocortical hormone, this product can increase their metabolic clearance rate, and the dose of corticosteroid must be adjusted.
4. Urine alkalizers, such as antacids, calcium or magnesium carbonates, citrate, sodium bicarbonate, etc., affect the excretion of this product in the urine, increase the half-life of this product, and extend the action time, especially if the urine remains alkaline for several days or longer, most patients will cause ephedrine poisoning, and the dosage of this product should be adjusted.
5. When used in combination with alpha receptor blockers such as phentolamine, prazosin, tolazolin and phenthiazide, it can resist the pressor effect of this product.
6. The same use with general anesthetics such as chloroform, halothane and isoflurane can make the heart muscle more sensitive to sympathomimetic amine drugs, which may lead to ventricular arrhythmia. If they must be used together, the dosage of this product should be reduced.
7. When used together with tricyclic antidepressants such as maprotiline, it can reduce the pressor effect of this product
8. Combined with digitalis glycosides, it can cause arrhythmia.
9. When used together with ergometrine, ergotamine or oxytocin, it can aggravate vasoconstriction, leading to severe hypertension or peripheral tissue ischemia.
10. When used together with doxapram, the pressor effect of both can be enhanced。
