What Is Albuterol?

Salbutamol, a short-acting 2 adrenergic receptor agonist, is used as an asthma drug, which can effectively inhibit the release of allergenic substances such as histamine and prevent bronchospasm. Adding a small amount of salbutamol to livestock feed can increase the lean meat amount, meat exchange rate and reduce fat of livestock, but its toxicity is much higher than that of ractopamine with the same function. For bronchial asthma, asthmatic bronchitis, bronchospasm, emphysema and other symptoms.

Chinese name: Salbutamol
Foreign name: salbutamol; ventolin; proventil
Alias: Methyl tert-butyl adrenaline, salbutamol, etc.

Chemical Name: 1- (4-hydroxy-3-hydroxymethylphenyl)
Molecular formula: C13H21NO3
Molecular weight: 239.31
The main purpose: Relieve obstruction of lung diseases such as asthma

Introduction to salbutamol compounds

Salbutamol Basic Information

Chinese name: Salbutamol

Chinese alias: 1- (4-hydroxy-3-hydroxymethylphenyl-2- (tert-butylamino) ethanol; Shuchuanling; Chuanling; salbutamol; hydroxymethyl tert-butyl adrenaline; Shuchuanling Cough is good; Sorbamine; Aisha; Aalin; Quantening; Sham; Pingchuanling; Hypromone

English name: albuterol

English alias: 3,6-dihydroxy-1-methyl-5-oxo-3,5-dihydro-2H-indolium betaine; 3-HYDROXY-1-METHYL-5,6-INDOLINE-DIONE; Salbutamol free base; 3- hydroxy-1-methyl-2,3-dihydro-indole-5,6-dione; adraxone; Proventil; Saltanol; Ventolin

CAS number: 18559-94-9

Molecular formula: C ₁₃ H ₂₁ NO ₃

Molecular weight: 239.31100

Exact mass: 239.15200

PSA: 72.72000

LogP: 1.69690

Salbutamol physical property data

Density (g / mL, 25/4 ): Uncertain

Relative vapor density (g / mL, air = 1): uncertain

Melting point (ºC): 157-158

Boiling point (ºC, atmospheric pressure): uncertain

Boiling point (ºC, 5.2kPa): Uncertain

Refractive index: uncertain

Flash point (ºC): Uncertain

Specific rotation (º): Uncertain

Spontaneous ignition point or ignition temperature (ºC): uncertain

Vapor pressure (kPa, 25ºC): uncertain

Saturated vapor pressure (kPa, 60ºC): uncertain

Combustion heat (KJ / mol): uncertain

Critical temperature (ºC): Uncertain

Critical pressure (KPa): Uncertain

Logarithm of oil-water (octanol / water) partition coefficient: uncertain

Upper explosion limit (%, V / V): Uncertain

Lower explosion limit (%, V / V): Uncertain

Solubility: insoluble in chloroform or ether ^[1]

Its sulfate is white or almost white crystalline powder. Odorless and slightly bitter. Slightly soluble in water, soluble in ethanol, slightly soluble in ether.

Salbutamol molecular structure data

1. Molar refractive index: 67.76

2. Molar volume (m / mol): 207.6

3. Isotonic specific volume (90.2K): 550.0

4. Surface tension (dyne / cm): 49.2

5. Polarizability (10cm): 26.86 ^[1]

Calculated Chemical Data for Salbutamol

1. Reference value for calculation of hydrophobic parameters (XlogP): 0.3

2. Number of hydrogen-bonded donors: 4

3. Number of hydrogen bond acceptors: 4

4. Number of rotatable chemical bonds: 5

5. Number of tautomers: 3

6. Topological molecular polar surface area (TPSA): 72.7

7. Number of heavy atoms: 17

8. Surface charge: 0

9. Complexity: 227

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 1

13. Determine the number of chemical bond stereocenters: 0

14. Number of stereochemical center of chemical bond: 0

15. Number of covalent bond units: 1 ^[1]

Salbutamol Safety Information

Packing level: III

Hazard category: 6.1 (b)

Customs Code: 2922509090

Dangerous Goods Transport Code: UN 3249

Danger category code: R22

Safety instructions: S36

Dangerous goods mark: Xn ^[2]

Salbutamol use

It is used for the treatment of asthmatic bronchitis, bronchial asthma, and emphysema caused by bronchial spasm. It is made by p-hydroxyacetophenone through chloromethylation, esterification, bromination, amination, and hydrolysis, neutralization, and hydrogenation. .

It is used as lean meat in modern pork farming to increase lean meat production in pigs. Since 2002, it has been listed as a banned drug in the breeding industry and must not be added to livestock and poultry breeding.

Gynecology and obstetrics are traditionally used in the treatment of preterm labor, but have not been included in the drug labeling.

Salbutamol Drug Analysis

Method name: Salbutamol API-Determination of Salbutamol-Non-aqueous titration

Scope of application: This method uses titration to determine the content of albuterol in the albuterol drug substance.

This method is applicable to salbutamol APIs.

Principle of the method: After the test product is dissolved in glacial acetic acid, the crystal violet indicator solution is added, and the solution is titrated with perchloric acid titration solution until the solution is blue. The titration result is corrected by a blank test, and the salbutamol is calculated according to the amount of titrant used. content.

Reagent: 1. Glacial acetic acid

2. Perchloric acid titrant (0.1mol / L)

3. Crystal violet indicator liquid

4. Reference potassium hydrogen phthalate

equipment:

Sample preparation: 1. Perchloric acid titration solution (0.1mol / L)

Preparation: Take 750mL of anhydrous glacial acetic acid (calculated with water content, add 5.22mL of acetic anhydride per 1g of water), add 8.5mL of perchloric acid (70 ~ 72%), shake well, let cool, add an appropriate amount of anhydrous glacial acetic acid 1000mL, shake well and leave for 24 hours. If the test sample is easily acetylated, the water content of the solution must be determined by the moisture measurement method, and then the water content of the solution is adjusted to 0.01% ~ 0.2% with water and acetic anhydride.

Calibration: Take about 0.16g of standard potassium hydrogen phthalate dried to constant weight at 105 , accurately weigh, add 20mL of anhydrous glacial acetic acid to dissolve, add 1 drop of crystal violet indicator solution, and slowly titrate with this solution to Blue, and the titration results are corrected with a blank test. Each 1mL of perchloric acid titration solution (0.1mol / L) is equivalent to 20.42mg of potassium hydrogen phthalate. Calculate the concentration of this solution based on the consumption of this solution and the amount of potassium hydrogen phthalate taken.

2. Crystal violet indicator liquid

Take 0.5 g of crystal violet and add 100 mL of glacial acetic acid to dissolve.

Operation steps: Precisely weigh about 0.2g of the test sample, add 25mL of glacial acetic acid to dissolve, add 1 drop of crystal violet indicator solution, titrate with perchloric acid titrant (0.1mol / L) until the solution becomes blue, and titrate The results are corrected with a blank test. Each 1mL of perchloric acid titration solution (0.1mol / L) is equivalent to 23.93mg of C ₁₃ H ₂₁ NO ₃ .

Note: "Precision weighing" means that the weighed weight should be accurate to one thousandth of the weighed weight. "Precision measurement" means that the accuracy of measuring the volume should meet the accuracy requirements of the volume pipette in national standards ^[3] .

Salbutamol Pharmacopoeia Standard

Source (name), content (potency) of salbutamol

This product is 1- (4-hydroxy-3-hydroxymethylphenyl) -2- (tert-butylamino) ethanol. Calculated on dry basis, containing C ₁₃ H ₂₁ NO ₃ shall not be less than 98.5%.

Salbutamol traits

This product is a white crystalline powder; it is odorless and almost tasteless.

This product is soluble in ethanol, slightly soluble in water, and insoluble in ether.

Melting point

The melting point of this product (Appendix VIC of Part Two of the 2010 Pharmacopoeia) is 154 ~ 158 ° C, and it will decompose at the same time when melting.

Optical rotation

Take about 0.50g of this product, weigh it accurately, place it in a 25ml measuring bottle, add methanol to dissolve and dilute to the mark, shake well, and measure it according to law (Appendix VI E of Pharmacopoeia Part II of 2010 Edition). The optical rotation should be -0.10 ° to + 0.10 ° ^[4] .

Salbutamol identification

(1) Take about 20mg of this product, add 2ml of water to dissolve, add 2 drops of ferric chloride test solution, shake, the solution is purple, add sodium bicarbonate test solution, the solution turns orange-red.

(2) Take this product, add 0.1mol / L hydrochloric acid solution to make a solution containing about 0.08mg per 1ml, and measure it by ultraviolet-visible spectrophotometry (Appendix IVA of Pharmacopoeia Part II of the 2010 edition). It has a wavelength of 276nm. Maximum absorption.

(3) The infrared absorption spectrum of this product should be consistent with the reference spectrum (Appendix IV C of Part Two of the Pharmacopoeia, 2010 Edition) ^[4] .

Salbutamol test

Color of ethanol solution

Take 0.40g of this product, add 10ml of absolute ethanol, and heat in a warm water bath to dissolve, such as colorimetric solution with the same volume (take 0.5ml of yellow stock solution plus 10ml of absolute ethanol) (Appendix 2 of the Pharmacopoeia of the 2010 edition A first method) comparison must not be deeper.

Albuterone

Take 50.0mg of this product, accurately weigh it, place it in a 25ml measuring bottle, add 0.01mol / L hydrochloric acid solution to dissolve and dilute to the mark, shake well, and apply the UV-visible spectrophotometry (Appendix IV A of Part Two of the 2010 Pharmacopoeia), The absorbance measured at a wavelength of 310nm shall not be greater than 0.10 (0.2%).

relative substance

Take an appropriate amount of this product, add the mobile phase to dissolve and dilute it to make a solution containing about 2mg per 1ml as the test solution; take 1ml precisely, place it in a 100ml measuring bottle, dilute to the mark with the mobile phase, shake well, as Control solution. Another appropriate amount of terbutaline sulfate reference and salbutamol reference was added, dissolved in mobile phase and diluted to make a solution containing about 0.2mg per 1ml, as a system suitability test solution. Tested according to high performance liquid chromatography (Appendix VD of Part Two of the Pharmacopoeia, 2010 edition), using octylsilane bonded silica gel as filler; sodium heptane sulfonate solution [take 2.87 g of sodium heptane sulfonate and potassium dihydrogen phosphate 2.5g, add water to dissolve and dilute to 1000ml, adjust the pH to 3.65 with phosphoric acid solution (1 2)-acetonitrile (78:22) as mobile phase; detection wavelength is 220nm. The resolution of the salbutamol peak and terbutaline sulfate should meet the requirements. Take 20 l of the control solution and inject it into the liquid chromatograph to adjust the detection sensitivity so that the peak height of the main component chromatographic peak is about 25% of the full scale. Precisely measure 20 l each of the test solution and the control solution (injected within 12 hours after preparation), and inject them into the liquid chromatograph respectively, and record the chromatogram to 25 times the peak retention time of the main component. If there is an impurity peak in the chromatogram of the test solution, the area of a single impurity peak must not be greater than 0.3 times (0.3%) the area of the main peak of the control solution, and the sum of the area of each impurity peak must not be greater than the area of the main peak of the control solution (1.0%). Any peak less than 0.05 times the area of the main peak of the control solution in the chromatogram of the test solution was ignored ^[4] .

Loss on drying

Take this product and dry it at 105 to constant weight, and the weight loss shall not exceed 0.5% (Appendix L of Part Two of the Pharmacopoeia of 2010 Edition).

Residue on ignition

Must not exceed 0.1% (Appendix N of Part Two of the 2010 Pharmacopoeia).

boron

Take 50mg of this product, add carbonate solution (take 1.3g of anhydrous sodium carbonate and 1.7g of potassium carbonate, add water to make 100ml) 5ml, evaporate to dryness in a water bath, dry at 120 ° C, and quickly burn for organic destruction and destruction. After completion, let cool, add 0.5ml of water and 3ml of fresh 0.125% curcumin glacial acetic acid solution, let the residue dissolve at a slight temperature, let cool, add 3ml of sulfuric acid-glacial acetic acid solution (1: 1), mix well, and let stand for 30 minutes Transfer to a 100ml volumetric flask, dilute to the mark with ethanol, shake, filter, and take the filtrate. According to UV-Vis spectrophotometry (Appendix IV A of Pharmacopoeia Part II of 2010 Edition), measure the absorbance at a wavelength of 555nm. Another appropriate amount of boric acid was added, dissolved with water and quantitatively diluted to make a solution containing 5.72 g per 1 ml. A precise amount was taken from 2.5 ml, starting from adding 5 ml of carbonate solution, and the same operation. The absorbance of the test solution shall not be greater than the absorbance of the control solution (50 parts per million) ^[4] .

Determination of salbutamol

Take about 0.2g of this product, accurately weigh, add 25ml of glacial acetic acid to dissolve, add 1 drop of crystal violet indicator solution, titrate with perchloric acid titration solution (0.1mol / L) until the solution becomes blue, and then titrate the result Calibration with blank test. Each 1ml of perchloric acid titration solution (0.1mol / L) is equivalent to 23.93mg of C ₁₃ H ₂₁ NO _{3 ^[4]} .

Salbutamol Categories

2 epinephrine receptor agonist.

Salbutamol storage

Shaded and sealed.

Salbutamol preparation

Salbutamol aerosol

Salbutamol Version

The 2010 Edition of the Pharmacopoeia of the People's Republic of China ^[4]

Salbutamol Drug Description

Salbutamol Classification

Circulatory Drugs> Antiarrhythmic Drugs> Treatment of Bradycardia

Salbutamol dosage form

1. Each bottle has a total weight of 18g and contains 20mg of albuterol, which can be sprayed at 200 , and each spray is 0.1mg;

2. Aisha, aerosol: each contains 20mg of salbutamol. Can spray 200 , each spray 0.1mg. ;

3. Ai Ling, slow-release capsules: each capsule contains salbutamol 4mg, 8mg;

4. Salbutamol, aerosol: 0.14%, 14g each contains 28mg of salbutamol;

5. Quantenin, controlled-release tablets: each tablet contains salbutamol sulfate

Salbutamol pharmacological effects

It has high selectivity for airway smooth muscle 2 receptors, increased resistance to catechin oxygen methyltransferase and monoamine oxidase, prolonged action time, and has little excitatory effect on the heart. In vitro experiments, comparison of equal strength concentrations required for airway smooth muscle and myocardial effects, to obtain the drug selectivity index, with salbutamol as high as 250, terbutaline as 138, and isoproterenol and adrenaline as 1.4. According to the observation of patients, comparing the changes in forced expiratory volume (FEV1) and heart rate with intravenous salbutamol and isoproterenol for 1 second, a small dose of salbutamol at 0.1 g / kg can significantly increase FEV1. Fang accelerates heart rate, showing high selectivity, and isoproterenol can increase heart rate when the FEV1 dose is increased, and the selectivity is poor ^[5] .

Salbutamol pharmacokinetics

Salbutamol is not easily destroyed by sulfatase in the digestive tract and catechol oxygen methyltransferase in tissues, so salbutamol is effective orally, and the effect lasts longer. Oral bioavailability is 30%, effective 15 to 30 minutes after taking the drug, the peak time of plasma drug concentration is 2 to 4 hours, and the effect lasts more than 6 hours. Elimination half-life is 2.7 ~ 5h. Salbutamol 8mg controlled release tablets have been tested repeatedly by healthy volunteers, and 90% of the drugs are released at a stable rate of 0.8mg / h. The drug is constantly released, avoiding fluctuations in blood drug concentration. Drug release rate is not affected by pH, gastrointestinal motility, and food intake. When inhaled, most of the inhaled dose is swallowed and then absorbed by the gastrointestinal tract. The bioavailability of the aerosol is 10%, which takes effect 1 to 5 minutes after inhalation and reaches a peak in 1 hour. Salbutamol is mostly metabolized in the intestinal wall and liver, and less than 20% of the original drug enters the blood circulation. After salbutamol is taken orally, 80% is excreted from the urine within 3 days ^[5] .

Salbutamol indications

It is used for various types of bronchial asthma and various bronchial and pulmonary diseases with bronchospasm; obstetrics is used to prevent and treat premature delivery, and can relieve placental vasospasm and increase placental blood flow. For sinus bradycardia, sinus arrest, sinus atrial block, atrioventricular block and other slow arrhythmias and heart failure ^[5] .

Salbutamol contraindications

Those who are allergic to salbutamol are contraindicated.

Salbutamol dosage

1. Acute or intermittent medication: 1 to 2 sprays per inhalation; maintenance or preventive medication: 2 sprays each time, 3 to 4 times a day; prevention of sports asthma: 2 sprays before inhalation. Child dose is halved.

2. Xichuan aerosol: usage and dosage are the same as above.

3. Chuanning tablets: 2 ~ 4mg per adult, 3 ~ 4 times per day. Children 2 to 6 years old, 1 to 2 mg each time; 6 to 12 years old, 2 mg each time, 3 to 4 times a day; those older than 12 years old are the same as adults.

4. Long-acting asthma (Tantenin): 8mg each time, once every 12 hours.

5. Chuanning injection: subcutaneous or intramuscular injection for adults: 500 g each time; intravenous: 250 g slow bolus for persistent asthma.

6. Chulening atomized solution: 0.5 ~ 2ml spray or intermittent positive pressure inhalation.

7. Shuchuanling tablets: 2.4 ~ 4.8mg each time, 3 ~ 4 times a day. Obstetric application should be used alternately with other antispasmodics, 1 week is a course of treatment, and can be reused every 1 week. Oral: 2.4 mg each time, 3 to 4 times a day.

(1) The more common adverse reactions are: tremor, nausea, increased heart rate or abnormally strong heartbeat.

(2) Rare adverse reactions: dizziness, dizziness, dryness of the oropharynx.

(3) Premature manifestations of overdose poisoning: chest pain, dizziness, persistent severe headache, severe hypertension, persistent nausea and vomiting, sustained rapid heart rate increase or strong heart rate, emotional irritability, etc. ^[5]

Salbutamol drug interactions

(1) If other adrenaline receptor agonists are used at the same time, the effect can be increased, and the adverse reactions may be worsened.

(2) When combined with theophylline, it can increase the effect of relaxing bronchial smooth muscle. May also increase adverse reactions.

(3) The bronchiectasis of this product can be antagonized by propranolol, which is a -blocker, so it should not be used with propranolol.

Salbutamol Precautions

(1) A few people see side effects such as nausea, headache, dizziness, palpitations, and finger tremor. When the dose is too large, tachycardia and blood pressure fluctuations can be seen. General reduction is recovery, and should be discontinued in severe cases.

(2) Those who are allergic to other adrenergic receptor agonists may be cross-allergic to this product.

(3) Long-term medication can also develop tolerance, which not only reduces the efficacy, but also may exacerbate asthma.

(4) The nebulizer of this product is contraindicated in patients with allergy to projectile freon.

(5) -blockers such as propranolol can antagonize the bronchiectasis of this product, so it should not be combined.

(6) Patients with cardiovascular insufficiency, insufficient coronary blood supply, hypertension, diabetes, and hyperthyroidism should be used with caution.

Salbutamol poisoning

The bronchodilator effect of salbutamol (Chuanning, Shuchuanling, methamphetamine epinephrine) is equal to isoproterenol, and the effect lasts longer; the effect of increasing heart rate is only 1/10 of isoproterenol. For the treatment of bronchospasm in patients with bronchial asthma, asthmatic bronchitis and emphysema, oral or aerosol inhalation. Oral bioavailability is about 30%, which takes effect for 15 to 30 minutes and lasts for more than 6 hours; bioavailability of aerosol inhalation is about 10%, which takes effect for 1 to 5 minutes, and the maintenance time is 4 to 6 hours.

Clinical manifestation

1. The more common adverse reactions during treatment are finger tremor, nausea, headache, dizziness, increased heart rate or blood pressure fluctuations. Less common adverse reactions include dizziness, dizziness, and dryness of the oropharynx.

2. Signs of overdose poisoning: chest pain, dizziness, persistent and severe headache, severe hypertension, persistent nausea and vomiting, sustained rapid heart rate increase or strong heartbeat, premature ventricular contraction, and emotional irritability. Can cause hypokalemia, the strongest effect 4h after taking.

diagnosis

The main points of diagnosis of salbutamol poisoning are:

There is a history of salbutamol application and the above manifestations appear.

treatment

The salient points of salbutamol poisoning are:

1. When the dose is too large, tachycardia and blood pressure fluctuations occur. Generally, the reduction can recover, and in severe cases, the drug should be discontinued. This medicine should be stopped immediately when bronchospasm occurs due to repeated overuse.

2. When the effect of this medicine is not good, it is not advisable to increase this medicine excessively, and other agonistic bronchial 2 receptor drugs may be replaced as appropriate.

3. Agitation, tachycardia, and peripheral vasodilation can be treated with beta blockers or benzodiazepines ^[6] .

Salbutamol Expert Reviews

Salbutamol Salbutamol is a relatively long-term clinical application of 1 receptor agonist. It is convenient to take, has little local irritation, good safety, and has a positive effect. The compound preparation composed of salbutamol and tranilast can not only exert the rapid antiasthmatic effect of salbutamol, but also exert the antiallergic effect of tranilast, and can also prevent the drug resistance phenomenon of salbutamol in long-term use. The compound Tranilast capsules composed of them are effective in asthma, the degree of improvement of symptoms and signs, the improvement of lung function and anti-allergic effect are better than salbutamol, the adverse reaction rate is low, and the blood pressure, heart rate, hematopoietic function and liver and kidney function are low. No adverse reactions to the heart. In addition, it can reduce the stress of uterine muscles on stimulation, relax the uterus, inhibit uterine contraction, use pregnancy, and prevent threatened abortion. It has obvious effect of relaxing bronchial smooth muscle, and is often used clinically for bronchial asthma, chronic bronchitis, emphysema, etc. It can also relax the uterine smooth muscle by exciting receptors, and have a fetal-preventing effect. In addition, the 1 receptor has a weak effect, and the effect of increasing heart rate is only 1/2 of the isoproterenol, so it is also used clinically as an anti- bradycardia drug ^[5] .

Salbutamol for threatened preterm labor

Analysis of 126 cases of threatened preterm labor with Shuchuanling sulfate

Summary

Objective To investigate the clinical significance of Shuchuanling Sulfate sulfate in threatened preterm labor. To observe the frequency and intensity of contractions of 126 cases of threatened preterm oral Shuchuanling sulfate. Results After treatment of 126 women with threatened premature labor, contractions were significantly suppressed. Conclusion Shuchuanling sulfate can effectively treat threatened preterm labor. Key words Shuchuanling sulfate threatened premature uterine contraction frequency

1 clinical data

1.1 Definition of case selection of premature infants: In 1962, the WHO adopted the gestation week <37 weeks as the diagnostic criteria for preterm births [1]. The definition of premature delivery in China refers to those who give birth after 28 weeks of pregnancy and less than 37 weeks of pregnancy. Conditions diagnosed as threatened preterm labor: (1) pregnancy at 28 to 37 weeks; (2) fetal membrane intact; (3) uterine opening within 75px; (4) duration of uterine contraction not exceeding 30s, with a gap of more than 10min.

1.2 Incidence: From January 1998 to September 2002, a total of 913 cases were delivered in our hospital, of which 126 cases of pregnant women from 28 weeks to 37 weeks (196 to 258 days) were treated, accounting for 13.8% of the total number of delivery.

1.3 Age and the situation of pregnant women 1.3.1 See Table 1 for the age distribution of primiparas. Table 1 shows that the minimum age of a primipara is 19 years old and the maximum is 35 years old, with an average age of 24.7 years. There were a total of 112 primiparas, accounting for 88.9% of the number of preterm births. Table 1 Age distribution of primiparas (omitted)

1.3.2 The distribution of maternal age is shown in Table 2. Table 2 shows that there were 14 cases of women undergoing delivery, accounting for 12% of the total number of women. The average age of women undergoing delivery was 32 years. Table 2 Distribution of maternal age (omitted)

1.3.3 Complications Among 126 pregnant women with threatened premature labor, there were 29 cases of pregnancy with acute and chronic diseases such as pregnancy induced hypertension, accounting for 23%. Among them, there were 7 cases with pregnancy-induced hypertension, 8 cases with anemia, 6 cases with normal liver function, but two-and-half were "two-yang" or "three-yang"; four were twins; the other four. See Table 3. Table 3 Distribution of pregnancy complications

2 treatments

For pregnant women who have been diagnosed with threatened preterm delivery, the first oral administration of Shuchuanling Sulfate 4.8mg is observed for 15-20 minutes; if the frequency or intensity of contractions is weakened, take 4.8mg orally for Q6h and maintain this dose. If the contraction does not decrease after 30 minutes, then add 2.4 to 4.8 mg, and then continue to take 4.8 mg, Q6h, and at the same time, symptomatic treatment for other complications.

3 results

126 cases of threatened preterm pregnant women were admitted to hospital for regular treatment, and their contractions were significantly suppressed. The gestational age was maintained to 39.7 weeks on average, and only 3 cases were delivered in less than 1 week, accounting for 2.3%. The newborn weighed an average of 3.23kg. Compared with a random sample of 126 pregnant women in the same year, the average gestational age was 40.2 weeks, and the weight of the newborn was 3.27 g. There was no significant difference between the two (P> 0.5). There was no significant increase in the incidence of neonatal deformity and asphyxia.

4 Discussion

Shuchuanling sulfate belongs to the class of adrenergic -receptor stimulants, which mainly has 2 -receptor stimulating effect, relaxes uterine smooth muscle, and inhibits uterine smooth muscle contraction activity, thereby inhibiting contractions. Suchuanling sulfate sulfate is absorbed by the gastrointestinal tract after oral administration, and generally exerts its effect after 15 minutes. The plasma concentration reaches a peak within 2 to 2.5 hours and is maintained for 4 to 5 hours. Its half-life is 2.7 to 5 hours. 80% of metabolites are distributed in the plasma, 76%. It is excreted most by urine and lasts for 3 days.

To improve the efficacy, the cause of premature birth should be identified. Only threatened premature birth due to contraction of the uterus is effective, but it is not effective for premature birth caused by normal cervical, uterine body, premature rupture of the membrane, etc. [2]. The intensity of contraction should be closely observed during treatment. Adjust the dose. In order to maintain the drug concentration in the blood, it should be taken orally once every 6 hours, avoiding taking it 3 or 4 times daily. Su Chuan Ling Sulfate Tablets contain a small amount of 1 -receptor excitatory ingredients, which have less side effects than oral administration. Occasionally, palpitations and arrhythmias after taking the medicine can be supplemented with oryzanol 10mg to control autonomic disorders and prevent heart palpitations Aggravated and satisfactory results. In this group of 126 patients, 1 case of pregnant women was not forced to stop the drug midway.

There is no literature report on the damage to the fetus or the newborn after the medication. There are reports in the literature about long-term application. Occasionally, the fetal heart rate increases, and the newborn temporarily has hypoglycemia. No similar symptoms were seen in the newborns in this group ^{[7-9 ]} .