Antibiotics Dr.K.Manivannan B.V.Sc.,

Antibiotics Are the metabolites produced by a group of organism which will kill or inhibit the growth of other organism Anti  Against Biota  living thing Ex Penicillin, Gentamicin, Tetracycline etc.,

Are the metabolites produced by a group of organism which will kill or inhibit the growth of other organism

Anti  Against Biota  living thing

Ex Penicillin, Gentamicin, Tetracycline etc.,

Antimicrobials / Antibacterials Are chemicals against microbes like bacteria Ex : Sulfonamoides

Are chemicals against microbes like bacteria

Ex : Sulfonamoides

Bacteriostatic Prevents the multiplication of organism Ex OTC Static  stops Bacteriocidal Kills the micro organism Ex Penicillins Cidal  Kills

Prevents the multiplication of organism

Ex OTC Static  stops

Bacteriocidal

Kills the micro organism

Ex Penicillins Cidal  Kills

Therapeutic concentration The plasma concentration that should be effective against most susceptible (sensitive) micro organism and also non toxic to the animal. MIC Minimum inhibitory concentration of drug in vitro( Micro gram / ml)

The plasma concentration that should be effective against most susceptible (sensitive) micro organism and also non toxic to the animal.

MIC

Minimum inhibitory concentration of drug in vitro( Micro gram / ml)

Bio- availability The rate and extend to which a drug administered as a particular dosage form enters the systemic circulation intact . Depends on Absorption Route Metabolism

The rate and extend to which a drug administered as a particular dosage form enters the systemic circulation intact .

Depends on

Absorption

Route

Metabolism

Pharmacokinetics Oral  Small Intestine  Entero Hepatic circulation  Liver  Metabolism  systemic circulation  Kidney  Excretion

Oral  Small Intestine  Entero Hepatic circulation  Liver  Metabolism  systemic circulation  Kidney  Excretion

Pharmacodyanamics Microbial Cell wall synthesis Protein synthesis Nucleic acid synthesis

Microbial

Cell wall synthesis

Protein synthesis

Nucleic acid synthesis

Resistance Ability of organisms against antibiotic action Plasmid mediated Mutation Reasons for Resistance Under dosage Improper usage /Prolonged ,preventive As a substitute for poor management

Ability of organisms against antibiotic action

Plasmid mediated

Mutation

Reasons for Resistance

Under dosage

Improper usage /Prolonged ,preventive

As a substitute for poor management

Classifications 1.Sulfonamides Chemotherapeutic agent Static Protein synthesis Synergism -Trimethoprim

1.Sulfonamides

Chemotherapeutic agent

Static Protein synthesis

Synergism -Trimethoprim

2.Penicillins By Penicillium notadum Cidal- cell wall synthesis Broad spectrum –Ampicillin,Amoxycillin Used in treatment of GD

By Penicillium notadum

Cidal- cell wall synthesis

Broad spectrum –Ampicillin,Amoxycillin

Used in treatment of GD

3.Tetracyclines Static – Protein synthesis 50s ribosome broad spectrum- OTC,CTC,DOXY Resistance- mutation, plasma mediated Drug residues in human food chain

Static – Protein synthesis 50s ribosome

broad spectrum- OTC,CTC,DOXY

Resistance- mutation, plasma mediated

Drug residues in human food chain

4.Aminoglycocides Cidal- protein synthesis 30 s ribosome Narrow spectrum – Gentamicin,Neomycin,streptomycin Resistance fast when under dosed Toxicity- Nephro, oto, neuro

Cidal- protein synthesis 30 s ribosome

Narrow spectrum – Gentamicin,Neomycin,streptomycin

Resistance fast when under dosed

Toxicity- Nephro, oto, neuro

5.Macrolides Cidal – Protein synthesis Narrow spectrum G + ve – Erythromycin Respiratory disease

Cidal – Protein synthesis

Narrow spectrum G + ve – Erythromycin

Respiratory disease

6.Lincosamides Cidal – Protein synthesis Narrow spectrum- Lincomycin

Cidal – Protein synthesis

Narrow spectrum- Lincomycin

7.Polymyxin B and colistin Cidal – Protein synthesis Narrow spectrum, GM – ve E. coli, salmonella ,enteric disease

Cidal – Protein synthesis

Narrow spectrum, GM – ve

E. coli, salmonella ,enteric disease

8.Chloramphenicol Cidal – Protein synthesis Broad spectrum Toxicity- Bone marrow depletion

Cidal – Protein synthesis

Broad spectrum

Toxicity- Bone marrow depletion

9.Tylosin static, Gm + ve, mycoplasma 10.Tiamulin Antibacterial,antimycoplasmal

static, Gm + ve, mycoplasma

10.Tiamulin

Antibacterial,antimycoplasmal

11.Cephalosporine 3 generations Related to penicillins Cidal-protein synthesis

3 generations

Related to penicillins

Cidal-protein synthesis

12.Nitrofurans Furazolidone Cidal-protein synthesis Static in low dose Slow resistance

Furazolidone

Cidal-protein synthesis

Static in low dose

Slow resistance

The End Thank you

Thank you