Principles Principles Of Of Antibiotics useAntibiotics use

Abdulrahman M. Al Mazrou,Abdulrahman M. Al Mazrou,FRCPCFRCPC

Professor of Pediatrics,KSUProfessor of Pediatrics,KSU

Consultant, Pediatric Infectious diseases,KFMCConsultant, Pediatric Infectious diseases,KFMC

Rajab-1431

ANTIBIOTICSANTIBIOTICS

ARE NOTARE NOT

ANTI-PYRETICSANTI-PYRETICS

Principles of antibiotics usePrinciples of antibiotics use

Principles of antibiotics usePrinciples of antibiotics use

Abx are widely used

Frequently abusedFrequently abused

Impact on individual and societyImpact on individual and society

WHY?

References & Further ReadingsReferences & Further Readings

R. Ress & R. Betts (ed): A practical approach to R. Ress & R. Betts (ed): A practical approach to infectious dis 3rd Editioninfectious dis 3rd Edition

Chavez-Bueno S, Stull T.Infect Dis Clin N Am2009;865Chavez-Bueno S, Stull T.Infect Dis Clin N Am2009;865 Hassan M., Kaye D. Inf Dis Clinic NAm, Sept 1995Hassan M., Kaye D. Inf Dis Clinic NAm, Sept 1995 R. Finch. Medicine. Vol 27, 1996R. Finch. Medicine. Vol 27, 1996 Pong A, Bradley J. Pediat Clin N Am 2005;52:869-94Pong A, Bradley J. Pediat Clin N Am 2005;52:869-94

Principles of antibiotics usePrinciples of antibiotics use

Is an antibiotic indicated?Is an antibiotic indicated? Have appropriate specimens been obtained?Have appropriate specimens been obtained? What organisms are likely to be responsible?What organisms are likely to be responsible? Which agent is best?Which agent is best? Is an antibiotic combination appropriateIs an antibiotic combination appropriate??

Consider the FollowingsConsider the Followings::

Principles of antibiotics usePrinciples of antibiotics use

Consider the Followings:Consider the Followings: Consider the Followings:Consider the Followings:

Any special host factors?Any special host factors? Best route of administrationBest route of administration What is the appropriate dose?What is the appropriate dose? Is modification needed later?Is modification needed later? Optimal duration of therapy?Optimal duration of therapy?

Principles of antibiotics usePrinciples of antibiotics use

Consider the FollowingsConsider the Followings::Consider the FollowingsConsider the Followings::

Is an antibiotic indicated?Is an antibiotic indicated? Have appropriate specimens been obtained?Have appropriate specimens been obtained? What organisms are most likely to be What organisms are most likely to be

responsible?responsible? Which agent is best?Which agent is best? Is an antibiotic combination appropriate?Is an antibiotic combination appropriate?

Principles of antibiotics usePrinciples of antibiotics use

Is An Antibiotic IndicatedIs An Antibiotic Indicated??Is An Antibiotic IndicatedIs An Antibiotic Indicated??

Clinical diagnosis of bacterial infectionClinical diagnosis of bacterial infection..• Localized : Localized : e.ge.g.cellulitis, pneumonia, .cellulitis, pneumonia, etcetc..

Probable bacterial infectionProbable bacterial infection• Urgent situationsUrgent situations• Non- urgent situationsNon- urgent situations

Principles of antibiotics usePrinciples of antibiotics use

Consider the FollowingsConsider the Followings::Consider the FollowingsConsider the Followings::

Is an antibiotic indicated?Is an antibiotic indicated? Have appropriate specimens been obtained?Have appropriate specimens been obtained? What organisms are most likely to be What organisms are most likely to be

responsible?responsible? Which agent is best?Which agent is best? Is an antibiotic combination appropriate?Is an antibiotic combination appropriate?

Principles of antibiotics usePrinciples of antibiotics use

Have Appropriate Specimens been Have Appropriate Specimens been Obtained?Obtained?Have Appropriate Specimens been Have Appropriate Specimens been Obtained?Obtained?

Important to:Important to:• Optimize chance of microbiological Dx.Optimize chance of microbiological Dx.• Help tailor therapy to specific pathogenHelp tailor therapy to specific pathogen ..

Should be:Should be:• ReliableReliable• AdequateAdequate• Appropriately transported and processedAppropriately transported and processed

Principles of antibiotics usePrinciples of antibiotics use

Consider the FollowingsConsider the Followings::Consider the FollowingsConsider the Followings::

Is an antibiotic indicated?Is an antibiotic indicated? Have appropriate specimens been obtained?Have appropriate specimens been obtained? What organisms are likely to be responsible?What organisms are likely to be responsible? Which agent is best?Which agent is best? Is an antibiotic combination appropriate?Is an antibiotic combination appropriate?

Cont…

Principles of antibiotics usePrinciples of antibiotics use

What organisms are likely to be responsibleWhat organisms are likely to be responsible??What organisms are likely to be responsibleWhat organisms are likely to be responsible??

““Best Educated Guess?Best Educated Guess? Based on:Based on:

• Hx & P.E.Hx & P.E.• Patient agePatient age• Epidemiological dataEpidemiological data

◘ Hospital-acquired vs. community-acquiredHospital-acquired vs. community-acquired◘ Prior antibiotic usePrior antibiotic use

• Prior culture dataPrior culture data

Principles of antibiotics usePrinciples of antibiotics use

Consider the FollowingsConsider the Followings::Consider the FollowingsConsider the Followings::

Is an antibiotic indicated?Is an antibiotic indicated? Have appropriate specimens been obtained?Have appropriate specimens been obtained? What organisms are most likely to be What organisms are most likely to be

responsible?responsible? Which agent is best?Which agent is best? Is an antibiotic combination appropriate?Is an antibiotic combination appropriate?

Cont…

Principles of antibiotics usePrinciples of antibiotics use

Which Agent is BestWhich Agent is Best??Which Agent is BestWhich Agent is Best??

A perfect antibiotic is:A perfect antibiotic is:

• Specific for targeted pathogensSpecific for targeted pathogens

• Adequate at site of infectionAdequate at site of infection

• Proven efficacyProven efficacy

• Minimal alteration of host natural floraMinimal alteration of host natural flora

• SafeSafe

• CheapCheap

Principles of antibiotics usePrinciples of antibiotics use

Consider the FollowingsConsider the Followings::Consider the FollowingsConsider the Followings::

Is an antibiotic indicated?Is an antibiotic indicated? Have appropriate specimens been obtained?Have appropriate specimens been obtained? What organisms are most likely to be What organisms are most likely to be

responsible?responsible? Which agent is best?Which agent is best? Is an antibiotic combination appropriate?Is an antibiotic combination appropriate?

Principles of antibiotics usePrinciples of antibiotics use

Is an Antibiotic Combination AppropriateIs an Antibiotic Combination Appropriate??Is an Antibiotic Combination AppropriateIs an Antibiotic Combination Appropriate??

IndicationsIndications

• Increase spectrum of coverage.Increase spectrum of coverage.

• Multiple organisms proven or likely.Multiple organisms proven or likely.

• Synergism.Synergism.

• Prevention of emergence of resistance.Prevention of emergence of resistance.

Cont…

Principles of antibiotics usePrinciples of antibiotics use

II

Indifference Synergism Antagonism

No drug No drug No drug

Drug ADrug A

Drug C

Drug BDrug B

Drug A

A + B

A + B

A + C

Hours after inoculation

I III

Disadvantages of combinations:Disadvantages of combinations:

• Increase adverse effectsIncrease adverse effects

• Increase colonization with resist. organismsIncrease colonization with resist. organisms

• Possibility of antagonismPossibility of antagonism

• Increase costIncrease cost

Is an Antibiotic Combination AppropriateIs an Antibiotic Combination Appropriate?? Is an Antibiotic Combination AppropriateIs an Antibiotic Combination Appropriate??

Principles of antibiotics usePrinciples of antibiotics use

Any special host factors?Any special host factors? Best route of administration?Best route of administration? What is the appropriate dose?What is the appropriate dose? Is modification needed later?Is modification needed later? Optimal duration of therapy?Optimal duration of therapy?

Consider the Followings:Consider the Followings: (Cont…)(Cont…)Consider the Followings:Consider the Followings: (Cont…)(Cont…)

Principles of antibiotics usePrinciples of antibiotics use

Consider Special Host FactorsConsider Special Host Factors::Consider Special Host FactorsConsider Special Host Factors::

Genetic e.g. G6PDGenetic e.g. G6PD Renal functionRenal function Liver functionLiver function Pregnancy & LactationPregnancy & Lactation Drug interactionDrug interaction

Principles of antibiotics usePrinciples of antibiotics use

Any special host factors?Any special host factors? Best route of administration?Best route of administration? What is the appropriate dose?What is the appropriate dose? Is modification needed later?Is modification needed later? Optimal duration of therapy?Optimal duration of therapy?

:Consider the Followings:Consider the Followings (…Cont)(…Cont) Consider the Followings:Consider the Followings: (Cont…)(Cont…)

Principles of antibiotics usePrinciples of antibiotics use

Best Route of AdministrationBest Route of AdministrationBest Route of AdministrationBest Route of Administration

Determined by:Determined by:

• Nature of infectionNature of infection

• Host factorsHost factors

• Drug factorsDrug factors Options:Options:

• Parenteral vs oral from startParenteral vs oral from start

• Sequential parenteral-oral therapySequential parenteral-oral therapy

Principles of antibiotics usePrinciples of antibiotics use

Any special host factors?Any special host factors? Best route of administration?Best route of administration? What is the appropriate dose?What is the appropriate dose? Is modification needed later?Is modification needed later? Optimal duration of therapy?Optimal duration of therapy?

Consider the Followings:Consider the Followings: (Cont…)(Cont…)Consider the Followings:Consider the Followings: (Cont…)(Cont…)

Principles of antibiotics usePrinciples of antibiotics use

What is the appropriate doseWhat is the appropriate dose??What is the appropriate doseWhat is the appropriate dose??

Avoid sub-therapeutic dosesAvoid sub-therapeutic doses Determined by:Determined by:

• Serious vs non-serious infectionsSerious vs non-serious infections• Site of infectionSite of infection• Drug PK/PD propertiesDrug PK/PD properties• Other host factors (e.g. renal function … etc)Other host factors (e.g. renal function … etc)

Principles of antibiotics usePrinciples of antibiotics use

““Lowest dose that is effectiveLowest dose that is effective””

Any special host factors?Any special host factors? Best route of administration?Best route of administration? What is the appropriate dose?What is the appropriate dose? Is modification needed later?Is modification needed later? Optimal duration of therapy?Optimal duration of therapy?

Consider the Followings:Consider the Followings: (Cont…)(Cont…)Consider the Followings:Consider the Followings: (Cont…)(Cont…)

Principles of antibiotics usePrinciples of antibiotics use

Any Modification NeededAny Modification Needed?? Any Modification NeededAny Modification Needed??

Principles:Principles: Narrow vs broad spectrum agents.Narrow vs broad spectrum agents. Least toxic agent.Least toxic agent. Cheaper.Cheaper.

Principles of antibiotics usePrinciples of antibiotics use

Any special host factors?Any special host factors? Best route of administration?Best route of administration? What is the appropriate dose?What is the appropriate dose? Is modification needed later?Is modification needed later? Optimal duration of therapy?Optimal duration of therapy?

:Consider the Followings:Consider the Followings (…Cont)(…Cont) Consider the Followings:Consider the Followings: (Cont…)(Cont…)

Principles of antibiotics usePrinciples of antibiotics use

Optimal Duration of TherapyOptimal Duration of Therapy Optimal Duration of TherapyOptimal Duration of Therapy

Established vs empirical.Established vs empirical. Avoid prolonged coursesAvoid prolonged courses::

• increase adverse effectsincrease adverse effects

• increase cost.increase cost.

Principles of antibiotics usePrinciples of antibiotics use

New is not always better!New is not always better! Most are expensiveMost are expensive Less experienceLess experience

New New VSVS Current Antimicrobial Agent Current Antimicrobial AgentNew New VSVS Current Antimicrobial Agent Current Antimicrobial Agent

Principles of antibiotics usePrinciples of antibiotics use

New VS Current Antimicrobial Agent (New VS Current Antimicrobial Agent (22))New VS Current Antimicrobial Agent (New VS Current Antimicrobial Agent (22))

Know:Know:

• approved indicationsapproved indications

• advantages vs disadvantagesadvantages vs disadvantages

• basic pharmacokineticsbasic pharmacokinetics◘serum T ½serum T ½◘activity at various siteactivity at various site◘……etc.etc.

• common adverse effectscommon adverse effects

Principles of antibiotics usePrinciples of antibiotics use

Accept new agents withAccept new agents with : :

• significant advantagessignificant advantages

• extensive testingextensive testing

New New VSVS Current Antimicrobial Agents ( Current Antimicrobial Agents (33))New New VSVS Current Antimicrobial Agents ( Current Antimicrobial Agents (33))

Principles of antibiotics usePrinciples of antibiotics use

Criteria for Use of New AgentCriteria for Use of New AgentCriteria for Use of New AgentCriteria for Use of New Agent

Antimicrobial activity is superiorAntimicrobial activity is superior Have a therapeutic advantageHave a therapeutic advantage Better pharmacokineticsBetter pharmacokinetics

– Site penetrationSite penetration

– Longer t ½Longer t ½

– Shorter durationShorter duration Less toxicLess toxic Better toleranceBetter tolerance

Principles of antibiotics usePrinciples of antibiotics use

AcetaminophenAcetaminophen

isis

the antipyreticthe antipyretic

of choiceof choice

Principles of antibiotics usePrinciples of antibiotics use

Thank youThank you