Saturday, 21 February 2015

MACROLIDE

                                  MACROLIDE


MECHANISM : Macrolide attaches to 50 s ribosome and block the translocation of peptide chain containing T RNA from A site to P site .


One must know about the TRANSLATION process happening in the bacterial cell to understand the above mechanism .

DRUGS :
  1. Erythromycin
  2. Roxithromycin 
  3. Clarithromycin
  4. Azithromycin
  5. Tacrolimus ( it is an immunosuppresant as well )
  6. Spiramycin 
PHARMACOKINETICS:

  1. All drugs are taken orally except spiramycin .
  2. Metabolised in liver
  3. These drugs are excreted in bile except Clarithromycin in urine.
  4. Do not cross blood brain barrier 
  5. Crosses placenta
USES:
MACROLIDES ARE BROAD SPECTRUM ANTIBIOTICS.

They are the drug of choices for the following:
  1. C -  Chancroid by Haemophilus ducreyi , Corneybacterium , Campylobacter
  2. L - Legionella
  3. A - Atypical pneumonia
  4. W- Whooping cough by Bordetella pertusis.
Mnemonic to remember the uses is CLAW .

Azithromycin has extended spectrum of uses :
  1. H.influenza
  2. Nesseria gonnorrhoea
  3. Urogenital infection by Chlamydia
Clarithromycin used as prophylaxis and treatment of Mycobacterium avium and H.pylori

Spiramycin is drug of choice for toxoplasmosis in PREGNANCY.

ADVERSE EFFECTS :
  1. ERYTHROMYCIN causes diarrhoea due to Motilin Stimulation.
  2. Erythromycin causes ACUTE CHOLESTATIC HEPATITIS
  3. Erythromycin , Clarithromycin , Roxithromycin causes microsomal enzyme inhibition .
    ALL THESE ADVERSE EFFECTS ARE ABSENT IN AZITHROMYCIN .















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