1. Ms. Mandakini Sampat Holkar
Assistant Professor
Dept. of Pharmaceutics
Shri Vithal Education and Research Institute’s
College of Pharmacy, Pandharpur
2. The macrolides are a class of natural products that consist of 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.
Some macrolides have antibiotic or antifungal activity and are
used as pharmaceutical drugs.
Introduction
4. The first macrolide discovered was erythromycin, which
was first used in 1952. Erythromycin was widely used as
a substitute to penicillin in cases where patients were
allergic to penicillin or had penicillin-resistant illnesses.
Later macrolides developed, including azithromycin and
clarithromycin,
History
5. Antibiotic macrolides are used to treat infections caused by Gram-
positive bacteria (e.g., Streptococcus pneumoniae) and limited Gram-
negative bacteria (e.g., Bordetella pertussis, Haemophilus influenzae),
and some respiratory tract and soft-tissue infections
Uses of macrolides Antibiotic
7. Erythromycin displays bacteriostatic activity or inhibits growth of bacteria,
especially at higher concentrations. By binding to the 50s subunit of the
bacterial rRNA complex, protein synthesis and subsequent structure and
function processes critical for life or replication are inhibited. Erythromycin
interferes with aminoacyl translocation, preventing the transfer of the tRNA
bound at the A site of the rRNA complex to the P site of the rRNA complex.
Without this translocation, the A site remains occupied, thus the addition of an
incoming tRNA and its attached amino acid to the nascent polypeptide chain
is inhibited. This interferes with the production of functionally useful
proteins, which is the basis of this antimicrobial action.
Mechanism of action
8. SAR
1.Cladinose at C3 gives good activity
removal of C3 –reduces the activity
2.C2 Fluoro group enhance the activity
3.Position no-9 oxime essential for activity.
4.C-13 modification with selected group provides
comparable spectrum activity.
5.Activity strongly depends up an substitution at C-6
6.Addition of nitogen atom to expand a 14-membred
precursor leads to an extended spectrum of action eg.
Azithromycin
10. Uses
Erythromycin is an antibiotic used for the treatment of a number of
bacterial infections. This includes respiratory tract infections, skin
infections, chlamydia infections, pelvic inflammatory disease, and
syphilis. It may also be used during pregnancy to prevent Group B
streptococcal infection in the newborn, as well as to improve delayed
stomach emptying. It can be given intravenously and by mouth. An eye
ointment is routinely recommended after delivery to prevent eye
infections in the newborn.
11. Azithromycin
Azithromycin is an antibiotic used for the treatment of a number of
bacterial infections.This includes middle ear infections, strep throat,
pneumonia, traveler's diarrhea, and certain other intestinal infections. It
can also be used for a number of sexually transmitted infections, including
chlamydia and gonorrhea infections. Along with other medications, it may
also be used for malaria. It can be taken by mouth or intravenously with
doses once per day
12. Clarithromycin, sold under the brand name Biaxin among others,
is an antibiotic used to treat various bacterial infections. This
includes strep throat, pneumonia, skin infections, H. Pylori
infection, and Lyme disease, among others. Clarithromycin can be
taken by mouth as a pill or liquid.
Clarithromycin