Zithromax is a macrolide antibiotic with a bacteriostatic effect. In high concentrations and in relation to highly sensitive microorganisms, it can have a bactericidal effect. It penetrates through the cell membrane of bacteria and reversibly binds to the subunit of 50S bacterial ribosomes. It inhibits the translocation of peptides from the acceptor site of the ribosome to the donor, inhibiting further protein synthesis.
Zithromax is active against:
- gram-positive bacteria: Streptococcus pyogenes, Streptococcus viridans, Streptococcus pneumoniae, Staphylococcus aureus, Corynebacterium diphtheriae, Corynebacterium minutissimum, Listeria monocytogenes;
- gram-negative bacteria: Bordetella pertussis, Legionella pneumophila, some strains of Haemophilus influenzae, Mycoplasma pneumoniae, as well as relative to Entaemoeba hystolitica, Chlamydia trachomatis, Treponema pallidum.
- gram-negative bacilli are resistant to the action of erythromycin: intestinal, Pseudomonas aeruginosa, as well as shigella, salmonella.
What Zithromax is used for?
- Infections of the respiratory tract, including SARS, infections of the ENT organs (tonsillitis, otitis media, sinusitis);
- Purulent-inflammatory diseases of the skin and its appendages;
- Legionnaires disease;
- Infections in dentistry and ophthalmology;
- Infections caused by microorganisms resistant to beta-lactam antibiotics, penicillin, tetracycline, chloramphenicol, streptomycin.
What do I need to tell the doctor before taking this medicine?
- Hypersensitivity to erythromycin or to any other component of the drug, to macrolides;
- Severe liver failure;
- Simultaneous use with terfenadine, astemizole, pimozide or cisapride, ergotamine, and dihydroergotamine.
What may interact with this medicine?
The combined use of Zithromax is contraindicated:
- astemizole or terfenadine, cisapride, pimozide: the risk of developing cardiotoxicity increases: prolongation of the QT interval, severe heart rhythm disturbances, including arrhythmias of the “torsade de pointes” type, cardiac arrest;
- ergotamine or dihydroergotamine: acute toxic reactions with vasospasm, dysesthesia are possible (erythromycin inhibits the metabolism of ergotamine and dihydroergotamine, increasing the vascular spasm associated with ergotamine).
The erythromycin biotransformation occurs mainly in the liver with the participation of the cytochrome P450 system. Erythromycin due to the effect on the activity of cytochrome P450 interacts with the following drugs:
- theophylline, aminophylline, caffeine: increases their concentration in blood serum and toxicity – it is necessary to reduce the doses of these drugs and control their concentration in blood serum;
- digoxin: increases absorption and its concentration in blood serum;
- cyclosporine: increases concentration and enhances its nephrotoxicity;
- carbamazepine: is able to reduce its hepatic metabolism, which allows reducing the dose of carbamazepine to 50% with the simultaneous use of drugs;
- phenytoin, alfentanil, methylprednisolone, benzodiazepines (such as triazolam, alprazolam), hexobarbital, valproic acid, tacrolimus, rifabutin, zopiclone, bromocriptine, cabergoline: increase the concentration and their toxicity – correction is necessary;
- disopyramide, quinidine, procainamide: may lengthen the QT interval or cause ventricular tachycardia;
- oral contraceptives: increases the risk of hepatotoxicity, reduces their effectiveness;
- antifungal drugs: it is possible to increase the risk of developing cardiotoxicity (lengthening the QT interval, paroxysmal ventricular tachycardia of the Pirouette type) and, as a result, cardiac arrest. The use of a combination of these drugs is contraindicated;
- anticoagulants (warfarin, Acenocoumarol): enhances their effects, which are more expressed in the elderly. Therefore, prothrombin time should be constantly monitored;
- HMG-CoA reductase inhibitors (for example, lovastatin, simvastatin): increases their concentration in the blood – increases the risk of rhabdomyolysis, which can usually develop after treatment with erythromycin;
- sildenafil (Viagra): enhances its systemic effect – it is necessary to reduce the dose of sildenafil;
- calcium channel blockers, such as felodipine, verapamil: slow down elimination and enhances their effect. There were reports of hypotension, bradyarrhythmias, lactic acidosis while taking them with erythromycin;
- zafirlukast: reduces its concentration in blood plasma;
- sulfonamides, tetracycline, streptomycin: increased action of erythromycin;
- colchicine, vinblastine: toxicity reported with interaction with erythromycin;
- cimetidine: leads to an increase in the risk of its toxicity, including reverse deafness;
- levodopa (in combination with carbidopa): inhibition of carbidopa absorption and a decrease in plasma levodopa levels are possible. With this combination, it is necessary to monitor the clinical picture. There may be required dose adjustment of levodopa;
- lincomycin, clindamycin, and chloramphenicol (antagonism), with drugs that increase the acidity of gastric juice, as well as with acidic drinks: cannot be used together since they inactivate Zithromax.
- The drug can affect the results of determining the level of catecholamines in the urine, carried out by a fluorometric method.
What are the side effects of Azithromycin tablets?
- Digestive system: nausea, vomiting, epigastric pain, cholestatic jaundice, tenesmus, diarrhea, dysbiosis, rarely – pseudomembranous enterocolitis, impaired liver function, increased activity of hepatic transaminases, pancreatitis.
- Allergic reactions: skin rash, urticaria, eosinophilia; rarely – anaphylactic shock, Stevens-Johnson syndrome, toxic epidermal necrolysis, interstitial nephritis, some rare cases of pancreatitis and seizures.
- Effects due to chemotherapeutic action: oral candidiasis, vaginal candidiasis. Cases of pseudomembranous colitis during or after antibiotic therapy are described.
- Sensory organs: reversible ototoxicity – hearing loss and/or tinnitus (when using high doses – more than 4 g/day).
- Cardiovascular system: rarely – tachycardia, lengthening of the QT interval, atrial fibrillation and/or flutter (in patients with an initially extended QT interval).
In the event of any of the above or other undescribed side effects, it is necessary to inform the doctor about them.
What are the symptoms of Zithromax overdose?
Symptoms: with acute intoxication, the appearance of nausea, vomiting, abdominal pain is characteristic. In chronic overdose, a violation of liver function (jaundice, hepatitis) develops, up to acute liver failure, often accompanied by fever, leukocytosis, eosinophilia. Allergic reactions from the skin, anaphylactic shock, and in rare cases, cholestatic hepatitis and even temporary hearing loss, especially in patients with renal failure, can be observed.
What is the treatment of Zithromax overdose?
Treatment: urgent gastric lavage with activated charcoal. Careful monitoring of the respiratory system (if necessary, mechanical ventilation). Gastric lavage is effective even when taking a dose five times higher than the average therapeutic. With the development of anaphylactic conditions, it is prescribed adrenaline, antihistamines, corticosteroids.