Macrolide

Jump to: navigation, search

WikiDoc Resources for Macrolide

Articles

Most recent articles on Macrolide

Most cited articles on Macrolide

Review articles on Macrolide

Articles on Macrolide in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Macrolide

Images of Macrolide

Photos of Macrolide

Podcasts & MP3s on Macrolide

Videos on Macrolide

Evidence Based Medicine

Cochrane Collaboration on Macrolide

Bandolier on Macrolide

TRIP on Macrolide

Clinical Trials

Ongoing Trials on Macrolide at Clinical Trials.gov

Trial results on Macrolide

Clinical Trials on Macrolide at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Macrolide

NICE Guidance on Macrolide

NHS PRODIGY Guidance

FDA on Macrolide

CDC on Macrolide

Books

Books on Macrolide

News

Macrolide in the news

Be alerted to news on Macrolide

News trends on Macrolide

Commentary

Blogs on Macrolide

Definitions

Definitions of Macrolide

Patient Resources / Community

Patient resources on Macrolide

Discussion groups on Macrolide

Patient Handouts on Macrolide

Directions to Hospitals Treating Macrolide

Risk calculators and risk factors for Macrolide

Healthcare Provider Resources

Symptoms of Macrolide

Causes & Risk Factors for Macrolide

Diagnostic studies for Macrolide

Treatment of Macrolide

Continuing Medical Education (CME)

CME Programs on Macrolide

International

Macrolide en Espanol

Macrolide en Francais

Business

Macrolide in the Marketplace

Patents on Macrolide

Experimental / Informatics

List of terms related to Macrolide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]


Erythromycin. The macrolide ring is the lactone (cyclic ester) at upper left.

File:Clarithromycin.svg File:Roxithromycin.svg

Overview

The macrolides are a group of drugs (typically antibiotics) whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14, 15 or 16-membered. Macrolides belong to the polyketide class of natural products.

Members

Common antibiotic macrolides

Developmental macrolides

Ketolides

Ketolides are a new class of antibiotics that are structurally related to the macrolides. They are used to fight respiratory tract infections caused by macrolide-resistant bacteria.

Others include spiramycin (used for treating toxoplasmosis), ansamycin, oleandomycin, carbomycin and tylocine.

Non-antibiotic macrolides

The drug tacrolimus (Prograf), which is used as an immunosuppressant, is also a macrolide. It has similar activity to cyclosporin.

Toxic macrolides

A variety of toxic macrolides produced by bacteria have been isolated and characterized, such as the mycolactones.

Uses

Antibiotic macrolides are used to treat infections such as respiratory tract and soft tissue infections. The antimicrobial spectrum of macrolides is slightly wider than that of penicillin, and therefore macrolides are a common substitute for patients with a penicillin allergy. Beta-hemolytic streptococci, pneumococci, staphylococci and enterococci are usually susceptible to macrolides. Unlike penicillin, macrolides have been shown to be effective against mycoplasma, mycobacteria, some rickettsia and chlamydia.

Mechanism of action

The mechanism of action of the macrolides is inhibition of bacterial protein biosynthesis by binding reversibly to the subunit 50S of the bacterial ribosome, thereby inhibiting translocation of peptidyl tRNA. This action is mainly bacteriostatic, but can also be bactericidal in high concentrations. Macrolides tend to accumulate within leukocytes, and are therefore actually transported into the site of infection.

A novel, non-antibiotic, anti-inflammatory effect of 14-membered macrolides was discovered in Japan (Kudo S. et al.), which is especially effective in improving control of diffuse panbronchiolitis (DPB). Research on the anti-inflammatory properties of the macrolide ring is ongoing.

Resistance

The primary means of bacterial resistance to macrolides occurs by post-transcriptional methylation of the 23S bacterial ribosomal RNA. This acquired resistance can be either plasmid-mediated or chromosomal, i.e through mutation, and results in cross-resistance to macrolides, lincosamides, and streptogramins (an MLS-resistant phenotype).

Two other types of acquired resistance rarely seen include the production of drug-inactivating enzymes (esterases or kinases) as well as the production of active ATP-dependent efflux proteins that transport the drug outside of the cell.

Side effects

A recent British Medical Journal article highlights that the combination of macrolides and statins (used for lowering cholesterol) is not advisable and can lead to debilitating myopathy. This is because macrolides are potent inhibitors of the cytochrome P450 system, particularly of CYP3A4. Macrolides also have a class effect of QT prolongation. Macrolides exhibit enterohepatic recycling; that is, the drug is absorbed in the gut and sent to the liver, only to be excreted into the duodenum in bile from the [[liver]. This can lead to a build up of the product in the system causing nausea.

References

  • Macrolide Antibiotics: Chemistry, Biology, and Practice, 2nd Edition, Ed. Satoshi Omura, 2002, Academic Press.

External links




ar:ماكرولايد de:Makrolide fo:Makrolid it:Macrolide nl:Macrolide antibioticum fi:Makrolidi sv:Makrolid



Linked-in.jpg