Azithromycin
DESCRIPTION
Azithromycin USP is an antibiotic
active against Gram-positive and Gram-negative organisms. Azithromycin
interferes with ribosome function in susceptible bacteria by inhibiting
the translocation of peptides.
INDICATIONS
Azithrocmycin is indicated for infections
caused by susceptible organisms; in lower respiratory tract infections
including bronchitis and pneumonia, skin and soft tissue infections,
otitis media and in upper respiratory tract infections including
sinusitis, pharyngitis and tonsillitis.
In sexually transmitted
disease in men and women Azithromycin is indicated in the treatment
of uncomplicated genital infections due to Chlamydia trachomatis.
CLINICAL PHARMACOLOGY
Azithromycin is a nitrogen containing
macrolide with actions similar to those of erythromycin.
Bioavailability of
Azithromycin is about 40% after oral administration and absorption
is reduced by food. Peak plasma concentrations are achieved 2
to 3 hours after a dose and Azithromycin is extensively distributed
to the tissues. High concentrations are taken up into white blood
cells. Small amounts of Azithromycin are demethylated in the liver,
and it is excreted in bile as unchanged drug and metabolites.
About 6% of an oral dose is excreted in the urine. The terminal
elimination half-life is approximately 40 hours.
DOSAGE AND ADMINISTRATION
Adult: Azithromycin should be given
as 500 mg once-daily orally for 3 days or as an alternative, given
over 5 days with 500 mg on day 1, then 250 mg on days 2-5.
For sexuallytransmitted
disease in adult caused by Chlamydia trachomatis, the dose is
1 g given as a single dose.
Normal adult dose is
recommended for elderly patients.
As common with many
other antibiotics, Azithrocmyin should be taken at least 1 hours
before or 2 hours after meal.
CONTRAINDICATIONS
Azithromycin is contraindicated for
patients hypersensitive to Azithromycin or any of the macrolide
antibiotics. Co-administration of ergot derivatives and Azithromycin
is contraindicated. Azithromycin is contraindicated in patients
with hepatic disease.
SIDE EFFECTS
Azithromycin is well tolerated with
a low incidence of side effects. Majority of the side effects
were mild to moderate in nature and of gastrointestinal in origin
with nausea, abdominal discomfort, vomiting, flatulence and diarrhea.
Allergic reactions such as rash have occurred and there have also
been rare reports of serious hypersensitivity reactions. Reversible
elevations in liver transaminases have been seen with a frequency
similar to the comparative macrolides and penicillins used in
clinical trials. Transient mild reductions in neutrophil counts
have occasionally been observed in clinical trials, although a
causal relationship to azithromycin has not been established.
PRECAUTIONS
As with any antibiotic, observation
for signs of super infection with non-susceptible organisms, including
fungi, are recommended. No dose adjustment is needed in patients
with mild renal impairment (creatinine clearance>40ml/min )
but as there is no data regarding the usage in patients with more
severe renal impairment thus caution should be exercised in using
Azithromycin in these patients.
USE IN PREGNANCY
AND LACTATION
Animal reproduction studies have
demonstrated that Azithromycin crosses the placenta, but have
not revealed any evidence of harm to the fetus. There are no adequate
and well controlled studies in pregnant women. Since animal reproduction
studies are not always predictive of human response, Azithromycin
should be used during pregnancy only if adequate alternatives
are not available. No data on secretion of Azithromycin in breast
milk is available, so, Azithromycin should only be used in lactating
women where adequate alternatives are not available.
DRUG INTERACTION
Azithromycin absorption is reduced
in presence of food and Antacid. So, Azithromycin should be administered
1 hour before or 2 hours after taking food or antacid. In-patients
receiving ergot alkaloids Azithromycin should be avoided concurrently
because of the possibility of ergotism resulting from interaction
of Azithromycin with the cytochrome P450 system. However no cases
of such interaction have been reported. Macrolides have been known
to increase the plasma concentration of digoxin and cyclosporin.
Therefore, if co-administration is necessary caution should be
exercised and serum level of digoxin and cyclosporin should be
checked. There have been no pharmacokinetic drug interaction between
Azithromycin and warfarin, theophylline, carbamazepine, methylprednisolone
and cimetidine.
OVERDOSAGE
There is no data of overdosage with
Azithromycin. Typical symptoms of overdosage with macrolide antibiotic
include hearing loss, severe nausea, vomiting and diarrhea. Gastric
lavage and general supportive measures are indicated.
|
Name of
Product
|
Pharmaceuticals
|
| AZ |
Aristopharma |
| Azalid |
Orion |
| Azicin |
Opsonin |
| Azin |
Acme |
| Azithrocin |
Beximco |
| Azix |
Amico |
| Azyth |
Novartis |
| Odazyth |
ACI |
| Zimax |
Square |
| Zithrin |
Renata |
| Zithrox |
Eskayef |
