Structure of Macrolides

Macrolides are composed of a large macrocyclic lactone ring to which one or more deoxy sugars are attached. This unique structure is responsible for their antibiotic activity.

Mechanism of Action

Macrolides work by binding to the bacterial ribosome, specifically the 50S subunit, and inhibiting the translocation step of protein synthesis. This prevents the addition of new amino acids to the growing peptide chain, ultimately leading to the inhibition of bacterial protein synthesis and growth.

Common Macrolide Antibiotics

• Erythromycin
• Azithromycin
• Clarithromycin

Indications for Use

Macrolide antibiotics are commonly used to treat respiratory tract infections, including pneumonia, bronchitis, and sinusitis. They are also effective against skin and soft tissue infections, as well as certain sexually transmitted infections such as chlamydia and gonorrhea.

Adverse Effects

Common side effects of macrolide antibiotics include gastrointestinal symptoms such as nausea, vomiting, and diarrhea. They may also cause liver enzyme abnormalities and, in some cases, cardiac arrhythmias.

Drug Interactions

Macrolides are known to interact with a variety of other medications. They can inhibit the metabolism of certain drugs, leading to increased levels and potential toxicity. It's important to consult a healthcare professional before taking macrolides in combination with other medications.

Resistance

Due to overuse and misuse of antibiotics, bacterial resistance to macrolides has become a significant concern. Bacteria can develop resistance through various mechanisms, such as efflux pumps and modification of the ribosomal target site.