Zithromax®, Zithromax® Single Dose Packets, Zithromax® Tri-Paks®, Zithromax® Z-Paks®, Zmax®
Azithromycin is used to treat certain bacterial infections, such as bronchitis; pneumonia; sexually transmitted diseases (STD); and infections of the ears, lungs, sinuses, skin, throat, and reproductive organs. Azithromycin also is used to treat or prevent disseminated Mycobacterium avium complex (MAC) infection [a type of lung infection that often affects people with human immunodeficiency virus (HIV).
Azithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria. Antibiotics will not kill viruses that can cause colds, flu, or other infections.
Azithromycin is also used sometimes to treat H. pylori infection, travelers’ diarrhea, and other gastrointestinal infections, Legionnaires’ disease (a type of lung infection), pertussis (whooping cough; a serious infection that can cause severe coughing), and babesiosis (an infectious disease carried by ticks). It is also used to prevent heart infection in people having dental or other procedures, and to prevent STD in victims of sexual assault. Talk to your doctor about the possible risks of using this medication for your condition.
Chemically and Mechanistically Related Drugs
Azithromycin is at least as effective as Minocycline in the treatment of facial comedonic and papulopustular acne.
Azithromycin may be somewhat more effective and better tolerated than Cefadroxil for treating uncomplicated skin and skin structure infections.
Cefdinir and Azithromycin have comparable effectiveness in the treatment of acute otitis media
Azithromycin has become a frequent choice for many common pediatric infections, including otitis media and pharyngitis. It appears to be as effective as traditional therapies, and offers the advantage of a shorter treatment course. Research continues with this drug, as new dosing regimens are proposed and additional patient populations are studied.
Use in the Elderly
Azithromycin (Zithromax and Zmax) poses the risk for a potentially fatal irregular heart rhythm, which therefore warrants careful screening of patients for this drug.
Patients at risk for this azithromycin-induced arrhythmia include those who already have a prolonged QT interval, low blood levels of potassium or magnesium, and an abnormally slow heart rate, or who take drugs to treat arrhythmias. Elderly patients and patients with cardiac disease also may be more susceptible to the arrhythmogenic effects of the antibiotic.
Azithromycin is one of the world best-selling antibiotics.
Zithromax – Pfizer’s branded version of Azithromycin – was one of the bestselling branded antibiotics in the United States and worldwide, with total sales peaking at US$ 2 billion in 2005 before starting to decline with the loss of patent protection in 2006 and resulting generics competition. However, the strong and proven Zithromax brand name has helped keep market share losses in check.
Azithromycin “pros” and “cons”
• Excellent efficacy. Many scientific studies have shown that azithromycin is better or equally effective compared to other antibiotics.
• Low potential for drug interactions. Azithromycin, unlike the majority of macrolides, does not bind to cytochrome P-450 in the liver, resulting in low potential for drug to drug interaction.
• Low rate of side effects. Side effects with azithromycin are mild to moderate, mostly gastrointestinal.
• Sustained antimicrobial activity. Azithromycin reaches high and sustained tissue concentrations that results in sustained antimicrobial activity.
• Active against intracellular bacteria (Chlamydia pneumoniae, Chlamydia trachomatis, Mycoplasma pneumoniae, Legionella spp.). Since azithromycin is a weak base, it easily penetrates the cell membrane and stays within the cell.
• Targeted activity at the site of infection. Because of the transport with white blood cells, azithromycin possesses a unique property – targeted activity at the site of infection. In infected tissues, azithromycin achieves high and sustained therapeutic concentrations that last five to seven days after the last dose.
• Suitable choice for empirical therapy. Since azithromycin has a good activity against the most common pathogens it is used as a choice for empirical therapy.
• Good compliance: short once daily dosing regimen. Azithromycin’s short dosing regimen is convenient and improves patient compliance. For the majority of infections, azithromycin is administered once daily for three days. In the treatment of sexually transmitted diseases, azithromycin is administered as a single dose.
• Active against most respiratory tract infections. Betalactams lack activity against atypical pathogens. Among macrolides, azithromycin shows the best activity against H. influenzae.
• Food reduces absorption rate of azithromycin capsules. Capsules should not be mixed with or taken with food, however tablets may be taken without regard to food.
• In 2013, the U.S. FDA sent out a communication stating that azithromycin may cause irregular heartbeats. However, in the study19 (published in the New England Journal of Medicine on May 2013) azithromycin use was not linked with an increased risk of death from cardiovascular (heart) causes in a general population of young and middle-aged adults.
Treatment guidelines increasingly recommend that certain antibiotics, particularly the macrolide azithromycin, no longer be used to treat many common infections. Inappropriate use has led to widespread antibiotic resistance and is contributing to the emergence of super bugs.
At least one prominent emergency medicine expert suggests that the drug not be used at all. The Canadian Pediatric Society strongly recommended that azithromycin not be used to treat acute pharyngitis, otitis media, or community-acquired pneumonia.