What Factors Affect a Sufficient Azithromycin Dose?

Azithromycin is a semi-synthetic 15-membered macrolide antibiotic.

Chinese name: Azithromycin
Foreign name: Azithromycin

CAS: 83905-01-5
Other name: Erythromycin, Azithromycin
Molecular formula: C38H72N2O12

Azithromycin indications

Applicable to the following infections caused by sensitive bacteria: lower respiratory tract infections such as bronchitis and pneumonia; skin and soft tissue infections; acute otitis media; upper respiratory tract infections such as sinusitis, pharyngitis and tonsillitis (penicillin is a commonly used medicine for the treatment of streptococcal pharyngitis) It is also a commonly used drug for the prevention of rheumatic fever. Azithromycin can effectively remove streptococcus in the oropharynx, but there is no data on the efficacy of azithromycin in the treatment and prevention of rheumatic fever). Azithromycin can be used for simple genital infections caused by Chlamydia trachomatis in sexually transmitted diseases in men and women. Azithromycin can also be used for simple genital infections caused by non-multidrug resistant gonococci and soft chancrees caused by Haemophilus Duke (complication of Treponema pallidum should be excluded).

Azithromycin clinical application

Take it orally once a day, swallow the entire tablet, and take it with food. Azithromycin tablets are used to treat various infectious diseases. The treatment course and method of use are as follows: For sexually transmitted diseases caused by Chlamydia trachomatis, Haemophilus Duke or Neisseria gonorrhoeae, only a single oral administration of 1000 mg of this product is required. Treatment of other infections: the total dose is 1500mg, and the product is 500mg once a day for three days. Or the total dose is the same. Take 500mg on the first day and 250mg orally once a day on the 2nd to 5th.

Azithromycin adverse reactions

(1) Blood and lymphatic abnormalities: Transient neutropenia is occasionally seen in clinical trials, but there is no data suggesting an association with azithromycin. Ear and labyrinth disorders: Some patients have experienced hearing loss after taking azithromycin, including hearing loss, tinnitus, and / or deafness. According to surveys and studies, this phenomenon is related to the continuous high-dose use of this product by patients. Through follow-up of these patients, the hearing of most patients was found to be recoverable. (2) Gastrointestinal disorders: nausea, vomiting, diarrhea, loose stools, abdominal discomfort (pain or cramps), flatulence. (3) Hepatobiliary system abnormalities: abnormal liver function. 2. Skin and subcutaneous soft tissue abnormalities: allergic reactions including rash and angioedema. After marketing, other adverse events reported during the use of this product include: (1) infection and transplantation: candidiasis and vaginitis. (2) Blood and lymphatic system abnormalities: thrombocytopenia. (3) Immune system abnormalities: allergic reactions (rarely fatal). (4) Metabolic and nutritional abnormalities: anorexia. (5) Mental disorders: aggressive response, nervousness, anxiety, anxiety. (6) Nervous system abnormalities: dizziness, convulsions (similar to other macrolides), headache, increased activity, dullness, paresthesia, lethargy, fainting. Rare reports of taste / olfactory inversion and / or absence. But it is not clear whether it is related to medication. (7) abnormal ear and labyrinth: dizziness. (8) Cardiac abnormalities: palpitations and arrhythmias, including ventricular tachycardia (like other macrolides) have been reported; rare reports of prolonged QT interval and apical torsional ventricular tachycardia. However, the above adverse events have not been confirmed to be related to azithromycin. (9) Vascular abnormalities: hypotension. (10) Gastrointestinal disorders: vomiting / diarrhea (rarely dehydrated), indigestion, constipation, pseudomembranous enteritis, pancreatitis, and discoloration of the tongue (rare).

Azithromycin precautions

1. As with erythromycin and other macrolides, rare severe allergic reactions such as angioedema and allergies (rarely fatal) are rare. Some reactions caused by azithromycin can recur, requiring longer observation and treatment. 2. Because the liver is the main route of azithromycin clearance, caution should be exercised when azithromycin is used in patients with significant liver disease. 3. There have been reports of ergot poisoning in patients receiving ergot derivatives when taking certain macrolide antibiotics at the same time. Although there is no data indicating that ergot and azithromycin have interactions, due to the theoretical possibility of ergot poisoning, azithromycin and ergot derivatives should not be administered at the same time. 4. As with other antibiotic preparations, pay attention to observe the symptoms of double infection caused by non-sensitive bacteria including fungi. 5. Almost all antibacterial applications have reported reports of Clostridium difficile-associated diarrhea (CDAD), including azithromycin, whose severity can range from mild diarrhea to fatal enteritis. Antibacterial treatment can cause changes in the normal colonic flora, leading to the overgrowth of Clostridium difficile. Clostridium difficile toxin A and toxin B are related to the pathogenesis of CDAD. Highly toxic Clostridium difficile causes increased morbidity and mortality. These infections may be ineffective against antimicrobial therapy and may require colectomy. For all patients with diarrhea after antibiotic use, the possibility of CDAD must be considered. Since there have been reports of CDAD occurring more than 2 months after antimicrobial treatment, a careful medical history is required. 6. In patients with severe renal insufficiency (glomerular filtration rate <10ml / min), the systemic exposure of azithromycin increased by 33%. 7. It has been reported that the application of other macrolide antibiotics can cause cardiac repolarization and prolongation of the QT interval, which may lead to the risk of arrhythmia and torsional ventricular tachycardia. When patients are at increased risk of prolonged cardiac repolarization, azithromycin cannot be completely ruled out to have similar effects as described above. 8. There is no evidence that azithromycin has an effect on patients' ability to drive and operate machines.

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Azithromycin contraindications

Those who are allergic to azithromycin, erythromycin or any other macrolide are contraindicated.

Azithromycin drug interactions

The antacid drugs containing aluminum and magnesium can reduce the peak blood concentration of azithromycin oral preparations, but not the AUC value.

Oral azithromycin did not affect theophylline levels or pharmacokinetics in plasma after a single dose of theophylline intravenously. Given that the macrolides currently used can increase plasma theophylline concentrations, caution should be exercised when using azithromycin and theophylline and monitoring of theophylline levels.

Oral azithromycin does not affect prothrombin time with a single dose of benzylacetone. However, care should be taken when azithromycin and benzylacetone are administered to patients, and the prothrombin time should be monitored. Because in the clinic, the simultaneous use of macrolides and benzylacetone will increase the efficacy of anticoagulants.

When azithromycin is used with the following drugs, it is recommended to observe the patient closely:

Digoxin-Increases digoxin levels.

Ergotamine or Dihydroergotamine-Symptoms of acute ergot toxicity are severe peripheral vasospasm and dullness (sensory pain).

Triazolam-By reducing the degradation of triazolam, the pharmacological effect of triazolam is enhanced.

Cytochrome P450 system metabolizers-increase the levels of carbamazepine, terfenadine, cyclosporine, cyclohexidine, phenytoin, etc. in serum.