What is/are Azithromycin?
Azithromycin (Zithromax, Azithrocin, Zmax, Azin) is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics. It is derived from erythromycin, with a methyl-substituted nitrogen atom incorporated into the lactone ring, thus making the lactone ring 15-membered.
Azithromycin is used to treat or prevent certain bacterial infections, most often those causing middle ear infections, strep throat, pneumonia, typhoid, bronchitis and sinusitis. In recent years, it has been used primarily to prevent bacterial infections in infants and those with weaker immune systems. It is also effective against certain sexually transmitted infections, such as nongonococcal urethritis, chlamydia, and cervicitis. Recent studies have indicated it also to be effective against late-onset asthma, but these findings are controversial and not widely accepted.
Azithromycin is used to treat many different infections, including acute otitis media, nonstreptococcal bacterial pharyngitis, gastrointestinal infections such as traveler's diarrhea, respiratory tract infections such as pneumonia, cellulitis, babesiosis, Bartonella infection, chancroid cholera, donovanosis, leptospirosis, Lyme disease, malaria, Mycobacterium avium complex disease, Neisseria meningitis, pelvic inflammatory disease, pertussis, scrub typhus, toxoplasmosis, and salmonellosis. It is used to prevent bacterial endocarditis and some sexually transmitted infections including those from unprotected sex or sexual assault. It is also effective against localized dental infections, uncomplicated skin and skin structure infections, urethritis and cervicitis and also genital ulcer disease.
It has a similar antimicrobial spectrum as erythromycin, but is more effective against certain Gram-negative bacteria, in particular, Haemophilus influenzae (although it would not be the first choice of treatment in this infection). Azithromycin resistance has been described and is endemic in many areas. Long-term use in treating Staphylococcus aureus infections with azithromycin may increase bacterial resistance to this and other macrolide antibiotics.
Azithromycin has been shown to be effective against malaria when used in combination with artesunate or quinine; the optimal dose for this is not yet known.
Most common side effects are gastrointestinal: diarrhea (5%), nausea (3%), abdominal pain (3%), and vomiting. Fewer than 1% of patients stop taking the drug due to side effects. Nervousness, dermatologic reactions, and anaphylaxis have been reported. As with all antimicrobial agents, pseudomembranous colitis can occur during and up to several weeks after Azithromycin therapy. In the past, physicians cautioned women that antibiotics can reduce the effectiveness of oral contraceptives. However, new research shows that antibiotics, with the exception of rifampin and rifabutin, do not affect the effectiveness of hormonal contraceptives, such as the pill, patch or vaginal ring. This change in advice comes because to date there is no evidence which conclusively demonstrates that antibiotics (other than rifampicin or rifabutin) affect these contraceptives.
Azithromycin suspension has an objectionable taste, so can be difficult to administer to young children, i.e., 2–5 years, who may spit it out.
Occasionally, patients have developed cholestatic hepatitis or delirium. Accidental intravenous overdosage in an infant caused severe heart block, resulting in residual encephalopathy.
In 2013, the FDA issued a warning saying that azithromycin "can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm." The FDA noted in the warning a 2012 study released by the New England Journal of Medicine that found the drug may increase the risk of death, especially in those with heart problems, compared with those on other antibiotics such as amoxicillin or no antibiotic. The warning indicated that people with preexistent conditions are at particular risk, such as those with QT interval prolongation, low blood levels of potassium or magnesium, a slower than normal heart rate, or those who use of certain drugs used to treat abnormal heart rhythms, or arrhythmias.
Mechanism of action
Azithromycin prevents bacteria from growing by interfering with their protein synthesis. It binds to the 50S subunit of the bacterial ribosome, and thus inhibits translation of mRNA. Nucleic acid synthesis is not affected.
According to Davis' Drug Guide for Nurses, following a single 500 mg dose, the half-life of azithromycin is 11–14 h. The longer half-life of 68 h is achieved only when multiple doses are consumed. Biliary excretion of azithromycin, predominantly unchanged, is a major route of elimination. Over the course of a week, approximately 6% of the administered dose appears as unchanged drug in urine.
What are azithromycin tablets?
AZITHROMYCIN (Zithromax®) is a macrolide antibiotic that interferes with the growth of bacterial cells. It is used to treat bacterial infections in many different parts of the body. Azithromycin also treats sexually transmitted vaginal or urinary tract infections caused by chlamydia. It will not work for colds, flu, or other virus infections. Generic azithromycin tablets are available.
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
• kidney disease
• liver disease
• stomach problems (especially colitis)
• other chronic illness
• an unusual or allergic reaction to azithromycin, other macrolide antibiotics (such as erythromycin), foods, dyes, or preservatives
How should I take this medicine?
Take azithromycin tablets by mouth. Follow the directions on the prescription label. Swallow tablets whole with a full glass of water. Azithromycin tablets can be taken with or without food. Take your doses at regular intervals. Do not take your medicine more often than directed. Finish the full course prescribed by your prescriber or health care professional even if you think your condition is better. Do not stop taking except on your prescriber's advice.
Contact your pediatrician or health care professional regarding the use of this medicine in children. Special care may be needed.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses. There should be an interval of at least 12 hours between doses.
What drug(s) may interact with azithromycin?
• magnesium salts
Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.
What side effects may I notice from taking azithromycin?
Side effects that you should report to your prescriber or health care professional as soon as possible:
Rare or uncommon:
• dark yellow or brown urine
• difficulty breathing
• severe or watery diarrhea
• skin rash, itching
• irregular heartbeat, palpitations, or chest pain
• yellowing of the eyes or skin
Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):
• dizziness, drowsiness
• hearing loss
• increased sensitivity to the sun
• stomach pain or cramps
• vaginal irritation, itching or discharge
What should I watch for while taking azithromycin?
Tell your prescriber or health care professional if your symptoms do not improve in 2 to 3 days. Contact your prescriber or health care professional as soon as you can if you get an allergic reaction to azithromycin, such as rash, itching, difficulty swallowing, or swelling of the face, lips or tongue.
Keep out of the sun, or wear protective clothing outdoors and use a sunscreen. Do not use sun lamps or sun tanning beds or booths.
If you get severe or watery diarrhea, do not treat yourself. Call your prescriber or health care professional for advice.
Antacids can stop azithromycin from working. If you get an upset stomach and want to take an antacid, make sure there is an interval of at least 2 hours since you last took azithromycin, or 4 hours before your next dose.
If you are going to have surgery, tell your prescriber or health care professional that you are taking azithromycin.
Where can I keep my medicine?
Keep out of the reach of children in a container that small children cannot open.
This article uses material from the Wikipedia article Azithromycin , which is released under the Creative Commons Attribution-Share-Alike License 3.0.