Macrolide Pharmacology


In this article we will discuss about Macrolide.

In this article, we will discuss about Macrolide. So, let’s gets started.


Macrolide is a class of antibiotic which are effective against Gram-positive bacteria (excluding enterococci) and limited Gram-negative bacteria, it is also effective against Mycoplasma pneumoniae, Treponema pallidum, Campylobacter spp., Bordella pertusis, Chlamydia trachomatis, Legionella spp., Borella spp., Chlamydophila pneumoniae and it includes following drugs as approved by US FDA:-





Mechanism of Action

Macrolide primarily has a bacteriostatic action; however, at higher concentration it may have bacteriocidal action. It acts by inhibiting bacterial protein synthesis by blocking 50S ribosomal subunit. It prevents enzymatic activity of peptidyltransferase thereby preventing addition of growing peptide attached to tRNA to next amino acid.

Drug interaction

Macrolide if taken with colchicine leads to colchicine toxicity symptoms includes GI upset, fever, myalgia, pancytopenia, and organ failure. It is not advisable to take combination of macrolide and statin as it leads to debilitating myopathy.


First line indication for:-

Pertusis (Erythromycin)

Community-acquired pneumonia (Erythromycin, its alternate is Roxithromycin)

H.pylori infection (Clarithromycin)

Acute non-specific urethritis (Azithromycin)

Chlamydia infection (Azithromycin)

Second line indication for:-

Cellulitis (Erythromycin)

Mastitis (Erythromycin)

Syphilis (Erythromycin)

Traveller’s diarrhea (Azithromycin)

Pelvic inflammatory disease (Azithromycin)

Adverse effects

GI upset such as abdominal pain, cramp, nausea, vomiting, and diarrhea

Note: Antibiotics and other medications should always be taken as prescribed by physician.

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