化合物信息

Drug Groups

approved

Description

Dirithromycin is a macrolide glycopeptide antibiotic. It is used to treat many different types of bacterial infections, such as bronchitis, pneumonia, tonsillitis, and even skin infections.

Indication

For the treatment of the following mild-to-moderate infections caused by susceptible strains of microorganisms: acute bacterial exacerbations of chronic bronchitis, secondary bacterial infection of acute bronchitis, community-acquired pneumonia, pharyngitis/tonsilitis, and uncomplicated skin and skin structure infections.

Pharmacology

Dirithromycin is a pro-drug which is converted non-enzymatically during intestinal absorption into the microbiologically active moiety erythromycylamine. Erythromycylamine exerts its activity by binding to the 50S ribosomal subunits of susceptible mircoorganisms resulting in inhibition of protein synthesis. Dirithromycin/erythromycylamine has been shown to be active against most strains of the following microorganisms both in vitro and in clinical infections: Staphylococcus aureus (methicillin-susceptible strains only), Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Legionella pneumophila, Moraxella catarrhalis, and Mycoplasma pneumoniae.

Toxicity

The toxic symptoms following an overdose of a macrolide antibiotic may include nausea, vomiting, epigastric distress, and diarrhea.

Affected Organisms

Biotransformation

Dirithromycin is converted by nonenzymatic hydrolysis during absorption to the active compound, erythromycylamine. Sixty to 90% of a dose is hydrolyzed to erythromycylamine within 35 minutes after dosing, and conversion is nearly complete after 1.5 hours. Erythromycylamine undergoes little or no hepatic biotransformation. No other metabolites of dirithromycin have been detected in the serum.

Absorption

Oral dirithromycin is rapidly absorbed, with an absolute bioavailability of approximately 10%. Dietary fat has little or no effect on the bioavailability of dirithromycin.

Half Life

The mean plasma half-life of erythromycylamine was estimated to be about 8 h (2 to 36 h), with a mean urinary terminal elimination half-life of about 44 h (16 to 65 h) in patients with normal renal function.

Protein Binding

15 to 30% for erythromycylamine, the active compound.

References

External Links