Antibiotics Antibiotics

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

AntibioticsAntibiotics

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

AntiAnti Against Biota Against Biota living thing living thing

Ex Penicillin, Gentamicin, Tetracycline Ex Penicillin, Gentamicin, Tetracycline etc.,etc.,

Antimicrobials / Antimicrobials / AntibacterialsAntibacterials

• Are chemicals against microbes like Are chemicals against microbes like bacteriabacteria

Ex : SulfonamoidesEx : Sulfonamoides

BacteriostaticBacteriostatic

• Prevents the multiplication of Prevents the multiplication of organismorganism

• Ex OTC StaticEx OTC Static stops stops

BacteriocidalBacteriocidalKills the micro organismKills the micro organism

Ex Penicillins CidalEx Penicillins Cidal Kills Kills

Therapeutic concentrationTherapeutic concentration

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

MICMICMinimum inhibitory concentration of Minimum inhibitory concentration of

drug in vitro( Micro gram / ml)drug in vitro( Micro gram / ml)

Bio- availabilityBio- availability

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

• Depends on Depends on

AbsorptionAbsorption

RouteRoute

Metabolism Metabolism

Pharmacokinetics Pharmacokinetics

•Oral Oral Small Intestine Small Intestine Entero Hepatic Entero Hepatic circulation circulation Liver Liver Metabolism Metabolism systemic systemic circulationcirculation Kidney Kidney ExcretionExcretion

PharmacodyanamicsPharmacodyanamics

Microbial Microbial

• Cell wall synthesisCell wall synthesis

• Protein synthesisProtein synthesis

• Nucleic acid synthesisNucleic acid synthesis

ResistanceResistance

• Ability of organisms against antibiotic actionAbility of organisms against antibiotic action• Plasmid mediatedPlasmid mediated• MutationMutation

Reasons for ResistanceReasons for Resistance

• Under dosageUnder dosage• Improper usage /Prolonged ,preventive Improper usage /Prolonged ,preventive • As a substitute for poor managementAs a substitute for poor management

ClassificationsClassifications

•1.Sulfonamides1.Sulfonamides

Chemotherapeutic agentChemotherapeutic agent

Static Protein synthesisStatic Protein synthesis

• Synergism -TrimethoprimSynergism -Trimethoprim

2.Penicillins2.Penicillins

• By By Penicillium notadumPenicillium notadum

• Cidal- cell wall synthesisCidal- cell wall synthesis

• Broad spectrum –Ampicillin,Amoxycillin Broad spectrum –Ampicillin,Amoxycillin

• Used in treatment of GDUsed in treatment of GD

3.Tetracyclines3.Tetracyclines

• Static – Protein synthesis 50s ribosomeStatic – Protein synthesis 50s ribosome

• broad spectrum- OTC,CTC,DOXYbroad spectrum- OTC,CTC,DOXY

• Resistance- mutation, plasma mediatedResistance- mutation, plasma mediated

• Drug residues in human food chainDrug residues in human food chain

4.Aminoglycocides4.Aminoglycocides

• Cidal- protein synthesis 30 s ribosomeCidal- protein synthesis 30 s ribosome

• Narrow spectrum – Narrow spectrum – Gentamicin,Neomycin,streptomycinGentamicin,Neomycin,streptomycin

• Resistance fast when under dosedResistance fast when under dosed

Toxicity- Nephro, oto, neuroToxicity- Nephro, oto, neuro

5.Macrolides5.Macrolides

• Cidal – Protein synthesisCidal – Protein synthesis

• Narrow spectrum G + ve – Narrow spectrum G + ve – ErythromycinErythromycin

Respiratory diseaseRespiratory disease

6.Lincosamides6.Lincosamides

• Cidal – Protein synthesisCidal – Protein synthesis

• Narrow spectrum- LincomycinNarrow spectrum- Lincomycin

7.Polymyxin B and colistin7.Polymyxin B and colistin

• Cidal – Protein synthesisCidal – Protein synthesis

• Narrow spectrum, GM – veNarrow spectrum, GM – ve

• E. coli, salmonella ,enteric diseaseE. coli, salmonella ,enteric disease

8.Chloramphenicol8.Chloramphenicol

• Cidal – Protein synthesisCidal – Protein synthesis

• Broad spectrumBroad spectrum

Toxicity- Bone marrow depletionToxicity- Bone marrow depletion

9.Tylosin9.Tylosin

• static, Gm + ve, mycoplasmastatic, Gm + ve, mycoplasma

10.Tiamulin10.Tiamulin

Antibacterial,antimycoplasmalAntibacterial,antimycoplasmal

11.Cephalosporine11.Cephalosporine

• 3 generations3 generations

• Related to penicillinsRelated to penicillins

• Cidal-protein synthesisCidal-protein synthesis

12.Nitrofurans12.Nitrofurans

• FurazolidoneFurazolidone

• Cidal-protein synthesisCidal-protein synthesis

Static in low doseStatic in low dose

Slow resistanceSlow resistance

The EndThe End

Thank youThank you