69-year-old Uncle Wang has chronic bronchitis and emphysema, recently due to colds, repeated dry cough and asthma for half a month, Uncle Wang thought that it would be good to eat aminophylline before, so he went to the pharmacy to buy a box of aminophylline tablets. After returning home, Uncle Wang felt that there must still be inflammation, so he put the anti-inflammatory drug roxithromycin and aminophylline prepared at home to eat together, did not expect to eat twice, Uncle Wang appeared nausea, vomiting, abdominal pain, headache, palpitation symptoms, went to the emergency department, electrocardiogram prompted ventricular arrhythmia, the doctor judged that aminophylline poisoning, emergency rescue, turn the crisis into safety.
Aminophylline this drug, ask the older people know that it is a medicine for asthma, this drug has a history of more than 70 years, many old slow branches and asthma patients may have taken this drug. However, neither the guidelines for bronchial asthma nor the copernic treatment guidelines are the first-line recommended medications. Why?
From the perspective of the mechanism of action, aminophylline has many effects. Manifested in:
1. It can relax the smooth muscle of the bronchi, relax the bronchi, and have a certain alleviating effect on the congestion and edema of the bronchial mucosa;
2. Increase the amount of heart discharge, have a certain cardiotonic effect, increase renal blood flow and glomerular filtration rate, and have a certain diuretic effect.
3. Theophylline drugs also have a certain role in dilating the coronary arteries, exciting the respiratory center and respiratory muscles.
4. It has the effect of expanding coronary arteries, exciting the respiratory center and respiratory muscles.
5. Immunomodulatory effect.
From the perspective of mechanism of action, aminophylline can be described as a very good asthma drug, which is good for the heart and kidneys, but the biggest disadvantage of this drug is that the therapeutic dose is very close to the poisoning dose, and its treatment window is very narrow. The effective blood concentration of aminophylline is maintained at 5-15ug/ml, and adverse reactions are easy to increase when it exceeds 20ug/ml, and may even cause theophylline poisoning. Whether there are adverse reactions to aminophylline, individual differences are very large, if long-term use or simultaneous use with other drugs, we must pay attention to monitoring the blood concentration of aminophylline.
Why does roxithromycin take it with aminophylline cause theophylline poisoning?
Many drugs will affect the clearance of aminophylline, and when these drugs are used at the same time, it is more likely to cause the blood concentration of theophylline in the body to increase, so that the probability of theophylline poisoning increases. It mainly includes the following types of drugs:
1. Some macrolides and quinolone antibacterial drugs
Macrolide antibiotics include erythromycin, roxithromycin, clarithromycin; fluoroquinolones such as enoxacin, ciprofloxacin, ofloxacin, levofloxacin, etc.; others, including clindamycin, lincomycin, etc., can reduce the clearance of theophylline in the body, increase its blood concentration, and thus be prone to theophylline poisoning, and the dose needs to be reduced when used in combination, and at least 1 hour apart.
2. Some antihypertensive drugs and drugs for the treatment of arrhythmias
Calcium antagonists diltiazem and verapamil, antiarrhythmic drugs propafenone, mexidine, and anthroporan, try to avoid combining with theophylline drugs when using these drugs, which may interfere with the metabolism of theophylline drugs in the liver, resulting in increased blood concentrations and poisoning.
3. H2 receptor antacpressants
When using the H2 receptor antacid inhibitor cimetidine, the use of aminophylline may lead to a decrease in the ability of the liver to metabolize aminophylline, causing its blood concentration to increase, and prone to symptoms of poisoning.
In addition, the use of theophylline drugs (aminophylline, doxofylline, compound methoxymethanine, etc.), try not to drink coffee or strong tea, theophylline drugs and caffeine have a mutual promotion of toxicity, the use of theophylline drugs and then drink coffee strong tea will accelerate the heart rate, aggravate the risk of arrhythmias.
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