Macrolides

Macrolides (see table: macrolides) are antibiotics that act primarily bacteriostatic. By binding to the ribosomal 50S subunit inhibit bacterial protein synthesis. Macrolides Azithromycin Drug Administration Oral or parenteral Clarithromycin Erythromycin Oral Oral Oral or parenteral Fidaxomicin telithromycin Oral Pharmacology Except for telithromycin (telithromycin), macrolides are orally relatively poorly absorbed. Fidaxomicin is minimally absorbed and is only active locally in the gastrointestinal tract. has taking to dinner the following effects on the macrolide absorption: When clarithromycin increased sustained release absorption When clarithromycin tablets or suspension immediate release no effect When azithromycin and erythromycin capsules (including base and stearate recipes), decreased absorption absorbed for fidaxomicin minimal effects Once macrolides, they diffuse well into body fluids except cerebrospinal fluid and accumulate in phagocytes. Excretion is primarily via the bile. Indications macrolides are effective against aerobic and anaerobic gram-positive cocci; up to the most enterococci, many strains of Staphylococcus aureus (especially methicillin-resistant strains), and some Streptococcus pneumoniae – and S. pyogenes strains. Mycoplasma pneumoniae Chlamydia trachomatis Chlamydophila pneumoniae Legionella sp Campylobacter sp Corynebacterium diphtheriae Treponema pallidum Borrelia burgdorferi Propionibacterium acnes, Bacteroides fragilis is resistant. Clarithromycin and azithromycin have a pronounced activity against Haemophilus influenzae and are effective against Mycobacterium avium complex. Macrolides have been regarded as drug of choice for infections caused by group A streptococci and pneumococci when penicillin could not be applied. However, pneumococci are reduced penicillin sensitivity often resistant to macrolides, and in some communities are up to 20% of the macrolide-resistant S. pyogenes. Because they are active against atypical pathogens of respiratory infections, they are often used empirically at low respiratory infections, however, another antibiotic is often required to cover macrolide resistant pneumococci. Macrolides have other clinical applications (see table: Some clinical applications of macrolides). Macrolides are not used to treat meningitis. Fidaxomicin is minimally or not at all against gram-negative bacteria active but is bactericidal against Clostridium difficile. Some clinical applications of macrolides drug indication comments macrolides infection by Mycoplasma pneumoniae, Legionella sp, or Bordetella pertussis eradication of Corynebacterium diphtheria in carriers drug of choice Symptomatic cat scratch disease (Bartonella henselae) – bacillary angiomatosis and peliosis hepatis in AIDS patients (henselae B. or B. quintana) – Azithromycin cerebral toxoplasmosis use with other medicines babesiosis use with other drugs Chlamydia trachomatis urethritis and -Zervizitis – clarithromycin and azithromycin Mycobacterium avium complex part of a multidrug scheme Erythromycin Uncomplicated skin infections – Acne taken Topical Application Preoperative bowel cleansing prior abdominal surgery Oral and together with an oral aminoglycoside used fidaxomicin Clostridium difficile – Contraindications macrolides in patients who are already a an allergic reaction uf they had contraindicated. Co-administration of macrolides with astemizole, cisapride, pimozide or terfenadine is contraindicated because potentially fatal cardiac arrhythmia (QT prolongation, ventricular tachycardia, ventricular fibrillation, torsades de pointes) may occur when clarithromycin or erythromycin is co-administered with these drugs. This effect is most likely due to the inhibition of metabolism of these drugs by erythromycin and clarithromycin. Clinical Calculator: QT interval correction (ECG) Use during pregnancy and lactation Erythromycin and azithromycin are in pregnancy category B (animal studies show no risk, human experience is incomplete or animal studies show risk, but human studies do not). Erythromycin is considered safer because the clinical application is much more extensive. Clarithromycin is Category C (animal studies show some risk indications in human studies are insufficient, but sometimes the clinical benefit outweighs the risk). Erythromycin applies during lactation as harmless. Nothing is known about the safety of other macrolides during lactation. Side effects The main points include indigestion (especially erythromycin) QT interval prolongation at Erythromycin Inhibition of hepatic metabolism, resulting in numerous drug interactions erythromycin often causes dose-related gastrointestinal disorders such. As nausea, vomiting, abdominal cramps and diarrhea; the disturbances are less common in clarithromycin and azithromycin. If the drug is taken with meals, this can help reduce the gastrointestinal Störungenzu. Erythromycin may cause a dose-related tinnitus, dizziness and reversible hearing loss. Cholestatic jaundice occurs most often in erythromycin. Jaundice usually occurs after 10 days of application, especially in adults, but can also appear early when the substance was administered before. Erythromycin is not i.m. administered because it causes severe pain on intravenous administration may lead to phlebitis or pain. Hypersensitivity reactions are rare. Erythromycin results in QT interval extensions and predisposes to ventricular tachyarrhythmias, particularly among women, in patients with QT prolongation or electrolyte imbalance, and in patients who are taking an additional medication which may prolong the QT interval. Considerations dosage for azithromycin, no dose adjustment for renal failure is necessary. Erythromycin and to some extent also clarithromycin interact with numerous medications because these hepatic metabolism by the cytochrome P-450 (CYP 450) inhibit system. When azithromycin drug interactions is the least likely. Interactions may occur when erythromycin or clarithromycin is taken with the following drugs: warfarin: Further increase in PT / INR lovastatin and simvastatin: rhabdomyolysis midazolam and triazolam: somnolence theophylline: nausea, vomiting, and seizures tacrolimus, cyclosporine and ergot alkaloids: Increased serum levels of these drugs

Health Life Media Team

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