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Are you just using aminophylline for cough and asthma?

Aminophylline is used as a respiratory medicine practitioner’s magic weapon, and it is most commonly used in asthma, bronchitis, and chronic obstructive pulmonary disease in patients with anti-inflammatory and asthma. In fact, its use is not limited to this.

 

Aminophylline is a purine derivative, a complex salt of theophylline and diethylamine. The pharmacological action is mainly from theophylline, and the amine salt plays an important role in helping to increase its water solubility. Stronger alkalinity, greater water solubility and greater local irritation. It has a strong direct relaxation effect on airway smooth muscle and has the same effect on the central airway and the peripheral airway.

Mechanism

1. Suppression of phosphodiesterase activity slows the rate of intracellular cAMP degradation, and relatively elevated cAMP levels cause a special phosphorylation process that causes airways to expand.

2. Antagonizes adenosine receptors against endogenous adenosine-induced bronchoconstriction.

3. Promote endogenous epinephrine release, increase catecholamine levels, indirectly lead to smooth muscle relaxation.

4. Relatively elevated cAMP levels can inhibit the influx of extracellular Ca2+ and the release of intracellular Ca2+, resulting in bronchodilator-like effects.

5. Strengthen diaphragm contraction and eliminate respiratory muscle fatigue.

6. Excited breathing center, increase breathing depth.

7. Promote airway cilia movement and increase the speed of mucociliary transfer.

8. Improve myocardial contractility, dilate blood vessels, reduce pulmonary vascular and coronary vascular resistance, dilate blood vessels.

9. Anti-inflammatory: IL-2, IL-6, TNF-α and other inflammatory factors that inhibit the production or release of inflammatory cells, increase the release of anti-inflammatory IL-10, and reduce the inflammatory cascade.

10. Anti-allergic: reduce the low vascular permeability and reduce the body’s absorption of allergens.

11. Regulate immune function: inhibit T lymphocyte apoptosis.

Pharmacokinetic characteristics

Orally easy to absorb, bioavailability close to 100%, half-life of 1-2 hours, different dosage forms reach the peak plasma concentration time is also different: 1 fast absorption type peaked at 1-2h after oral administration, 2 slow release type after oral 4- At the peak of 6h, the sustained release agent reached its peak on the 31st at 8-12h. The scope of safety is very narrow, and blood drug concentrations above the therapeutic level can cause adverse reactions.

 

Clinical application

1 Bronchial Asthma
Oral aminophylline can reduce the severity of persistent asthma symptoms and reduce the frequency of attacks. For some inhaled or oral high-dose glucocorticoid treatment is ineffective or not sensitive to β2-agonists are effective treatment of this product. Oral aminophylline or controlled-release theophylline is suitable for mild-to-moderate asthma attacks and maintenance therapy. Orally controlled (relieved) release theophylline is particularly suitable for the control of nocturnal asthma symptoms. Intravenous administration is suitable for severe acute asthma attacks.

2 Chronic obstructive disease (COPD)
Low-dose theophylline treatment of chronic obstructive pulmonary disease, can induce a significant decrease in the total number of inflammatory cells and neutrophils, neutrophil chemotaxis is also reduced. Aminophylline also inhibits the exudation of plasma proteins caused by inflammatory stimuli to the airway. In addition, theophylline can enhance diaphragmatic function and strength, and increase blood flow to the diaphragm, which can prevent and reduce diaphragmatic fatigue in patients with chronic obstructive pulmonary disease. , Enhances hypoxic respiration drive, resists hypoxic respiratory depression and improves lung function.

3 pulmonary hypertension
Aminophylline can directly change the Ca2+ concentration in the pulmonary artery wall and reduce the Ca2+ outflow, inhibit the phosphodiesterase activity and relax the smooth muscle, reduce pulmonary vascular resistance and pulmonary artery, reduce pulmonary vascular extravasation, and eliminate pulmonary edema.

4 Bradyarrhythmias – Sick Sinus Syndrome (SSS)
Aminophylline as theophylline can promote the release of endogenous epinephrine and isoproterenol, and it acts on cardiac β receptors to strengthen myocardial contractility and speed up heart rate. In addition, aminophylline activates the catecholamine system, promotes sympathetic activation of the heart, inhibits vagus nerve, and increases heart rate. At the same time, theophylline is an adenosine antagonist that can competitively bind to the adenohypoxia receptor to affect the opening of the K+ channel, inhibit the outflow of K+, increase the intracellular K+ concentration, and increase the heart rate.

5 Acute fetal distress in the fetus
Aminophylline can increase uteroplacental blood flow by 21% to 45%, and can increase the permeability of placental blood vessels and the production of pulmonary surfactant. Combined with sodium bicarbonate can improve the fetal placental circulation, increase the diffusion of O2 and CO2 between mother and fetus, and the transport of H+ and HCO3-, so that the utilization of oxygen and sodium bicarbonate can be improved in a unit time, and the partial contractions are too strong. Play an effective role in inhibiting contractions, thereby improving the fetus’s hypoxia and acidosis, and improving fetal distress.

6 Prevention of asphyxia in preterm infants
The use of aminophylline during pregnancy can increase fetal lung surfactant, promote fetal lung maturation, and increase uteroplacental blood flow by 21% to 45%. Fetal myocardial contractility and cardiac output increase, thereby improving fetal hypoxia. status. Dexamethasone combined with aminophylline intravenous in pregnant women with threatened preterm birth can effectively reduce the incidence of asphyxia in preterm infants and neonatal ARDS.

7 Infantile bronchiolitis
Aminophylline can inhibit the activation of inflammatory cells in children with bronchiolitis and release of mediators, stabilize mast cells, prevent their degranulation and allergens caused by delayed-phase asthma response and subsequent airway reactions, and reduce Tracheal inflammatory response, reduce airway mucin sialylation, significantly improve the role of lung function in children. In addition aminophylline can increase ciliary epithelial cells of the airway ciliary, to promote the removal of secretions, it can reduce the small airway obstruction, especially for infants not suitable for inhaled therapy, can relax the bronchial smooth muscle spasm, reduce tracheal mucosal edema and Inflammation reduces mucus secretion, thereby controlling seizures and shortening the course of the disease.

8 Wake up after general anesthesia
Most intravenous anesthetics can play a role by regulating adenosine function, and aminophylline can compete with brain adenosine receptors, so that the brain sleep-wake system imbalance in neuronal content or affect the synaptic transmission, stimulate the central nervous system Induced wakefulness, shortened wake time.

9 Brain protection during extracorporeal circulation
In the open heart surgery, the cardiopulmonary bypass can stimulate the systemic inflammatory cascade, leading to the expression and release of TNF-α, IL-6, IL-8 and other inflammatory factors, promoting the formation of brain edema, destruction of blood-brain barrier, and degeneration and necrosis of neurons. Causes brain damage. The anti-inflammatory effects of low concentrations of aminophylline can reduce the heart’s ischemia-reperfusion injury during cardiopulmonary bypass, reduce brain damage, and play a very good role in brain protection.

10 Prevention of Kidney Damage Caused by Radiography Drugs
Hyperosmolar contrast drugs can increase intracellular sodium transport in the renal tubules after injection into the human body, causing adenosine production in the kidney and activating calcium-dependent vasoconstriction. The contrast agent increases the influx of calcium ions in the renal tubular cells, increases the concentration of intracellular calcium ions, and causes damage to renal tubular cells. Aminophylline intravenous infusion can better prevent the decrease of glomerular filtration rate caused by contrast drugs, decrease renal tubular damage, and prevent drug-induced renal failure by antagonizing the transport of adenosine and calcium ions.

11 Renal colic caused by urinary stones
Urinary system stones often cause urinary retention in the renal pelvis, ureteral obstruction, and then expand and stimulate the smooth muscle wall, so that increased excitability of the smooth muscle, and constantly strengthen the peristalsis, further stimulate the smooth muscles of the abnormal strong peristalsis, expansion and extrusion of the renal capsule # cause clinical Renal colic causes renal colic and produces a large number of inflammatory pain factors. Aminophylline indirectly inhibits the release of histamine, leukotrienes, and other inflammatory mediators through PDE activity, antagonizes prostaglandins, decreases the sensitivity of the body’s pain receptors to inflammatory stimuli, and increases the body’s pain threshold. In addition, aminophylline can increase adrenal secretion of adrenal medulla, promote the release of endogenous epinephrine and norepinephrine, and then relax the kidney, ureteral smooth muscle and relieve renal colic.

12 Sepsis
In patients with sepsis, there are capillary endothelial cell damage, increased vascular permeability, microcirculatory dysfunction, myocardial inhibition and effective circulating blood volume reduction, clinical manifestations are mostly systemic severe edema but at the same time there is insufficient circulating blood volume, early target treatment Later, some patients developed systemic edema and aggravated. Infusion of aminophylline can inhibit the activity of phosphodiesterase, increase the content of cyclic adenosine and cyclic guanosine, antagonize adenosine receptors, and inhibit the release and production of inflammatory factors. Therapeutic doses of aminophylline can release catecholamines from the adrenal medulla, increase blood catecholamine levels, and increase myocardial contractile function.

Precautions

1. The therapeutic dose and toxic dose are close to each other, and the safety range is relatively narrow. Improper use may cause poisoning and even death. The blood drug concentration should be dynamically monitored during application.

2. Blood pressure is significantly lower or the patient is banned with acute myocardial infarction.

3. The aminophylline intravenous preparation can not be exposed to the air, it will lead to oxidation yellowing, drug failure.

4 aminophylline greater gastrointestinal irritation, may have nausea, vomiting and other adverse reactions, should be taken after meals.

5. Adult oral dosage 0.1-0.2g per day, the total daily dose should not exceed 1g; children each 3-5mg/kg, no more than 3 times.

6. Avoid oral and intravenous administration.

7. Aminophylline as a strong alkaline drug, local irritation of intravenous medication, local swelling and pain after leakage, to be treated in time to prevent skin necrosis, intravenous medication should be observed.

8. The symptoms of poisoning appear in the course of medication, and should be stopped immediately. Once the symptoms and signs of shock such as palpitation, shortness of breath, irritability, blood pressure drop, and arrhythmia, etc. should be immediately rescued, use of adenosine to antagonize the cardiovascular caused by aminophylline The side effects of the system, oxygen, blood transfusion, correct hypokalemia, actively protect the nervous system, hemodialysis when the condition is serious…….

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