Antibiotic Selection. Part 1 What Drug for What Bug Dr.T.V.Rao M D Professor, Department of Microbiology Jubilee Mission Medical College, and Research Institute, Thrissur, Kerala. India E mail ;tvraodoctor2000@yahoo.co.in

Basic Principles. Proper use Favorable results Indiscriminate use Drug Resistance Emerging Problem May produce Adverse Reactions.

Proper use Favorable results

Indiscriminate use Drug Resistance

Emerging Problem

May produce Adverse Reactions.

Decision Making. Decide first that one is treating a Bacterial Infection. Mild Wait Moderate Consider starting earliest Severe Don’t loose time ( Best guess is life saving )

Decide first that one is treating a Bacterial

Infection.

Mild Wait

Moderate Consider starting earliest

Severe Don’t loose time

( Best guess is life saving )

Skills In Antibiotic Therapy. Seniors - Colleagues – Juniors Follow Most General Practitioners Dangerous trend Promotional Best way learn your own skills.

Seniors - Colleagues – Juniors Follow

Most General Practitioners

Dangerous trend Promotional

Best way learn your own skills.

Etiological Diagnosis Do we need to know about causative agent always ? No Development of skills apply to the situation. But the following conditions warrant a good knowledge on causative agent. CNS, Hepatobiliary,Renal Systemic infections, Bacteremias Cardiac infections.

Do we need to know about causative agent always ? No

Development of skills apply to the situation.

But the following conditions warrant a good knowledge on causative agent.

CNS, Hepatobiliary,Renal Systemic infections, Bacteremias Cardiac infections.

What is best guess. Past experience of Antibiotic therapy, Basic principles of antibiotic therapy, Many times best guess is life saving. Many surveys prove -- Physicians in Developing Nations Depending on Best guess.

Past experience of Antibiotic therapy,

Basic principles of antibiotic therapy,

Many times best guess is life saving.

Many surveys prove -- Physicians in Developing Nations

Depending on Best guess.

Role of Microbiological Diagnosis. Start collecting desired samples before starting antibiotic therapy. Consider the Technical soundness of the Laboratories. Many times Normal flora are reported as pathogens, and misguide the Junior Physicians.

Start collecting desired samples before starting antibiotic therapy.

Consider the Technical soundness of the Laboratories.

Many times Normal flora are reported as pathogens, and misguide the Junior Physicians.

Judgment on Clinical response. In routine circumstances if the best guess works ignore Microbiological reports In Poor response consider evaluation of Microbiology reports.

In routine circumstances if the best guess

works ignore Microbiological reports

In Poor response consider evaluation of Microbiology reports.

Adherence to Microbiology Reports Isolates from Blood, CSF,Body Fluids, A significant finding. Implement the Microbiology Reports

Isolates from

Blood, CSF,Body Fluids,

A significant finding.

Implement the Microbiology

Reports

Dealing with unexpected results. When the isolates from Respiratory tract, GUT system Surface lesions. Think before changing Antibiotics Many occasions Specimens are not properly collected. Major failures are attributed to collecting and sending a ideal Sample.

When the isolates from

Respiratory tract, GUT system

Surface lesions.

Think before changing Antibiotics

Many occasions Specimens are not properly collected.

Major failures are attributed to collecting and sending a ideal Sample.

Drug susceptibility Testing. Always needed ? No e.g. Group A hemolytic streptococci. Clostridial infection,

Always needed ? No

e.g. Group A hemolytic streptococci.

Clostridial infection,

Drug susceptibility Testing. Most Important in Enterobacteriaceae Majority of times stick to antibiotic sensitivity patterns,

Most Important in

Enterobacteriaceae

Majority of times stick to antibiotic sensitivity patterns,

Current Trends Get familiar with your own ward reports. All the knowledge from Journals May not suit local situations Get familiar with Daily isolates and the Antibiotic patters, eg Pneumococcus,Enterococci Be familiar with Changing pattern of resistance e.g. Penicillin's ,Aminoglycosides,Vancomycin.

Get familiar with your own ward reports.

All the knowledge from Journals

May not suit local situations

Get familiar with Daily isolates and the Antibiotic patters,

eg Pneumococcus,Enterococci

Be familiar with Changing pattern of resistance

e.g. Penicillin's ,Aminoglycosides,Vancomycin.

Failed Responses. One May not be treating a Bacterial Infection. Selection of Inappropriate Drug, Dosage, Improper Administration. Missing a Pocket of Localized pus, Poorly diffusing drugs Don't reach target, e.g. Cefoperazone in meningitis,

One May not be treating a Bacterial Infection.

Selection of Inappropriate Drug, Dosage,

Improper Administration.

Missing a Pocket of Localized pus,

Poorly diffusing drugs

Don't reach target, e.g. Cefoperazone in meningitis,

Failed responses( Cont ) Super infection replacing primary infection, Suppression of Normal Flora. Fast emerging drug resistant strains, Two or More pathogens present But treating one only. Growing problems with Immune deficiencies,Diabetus.

Super infection replacing primary infection,

Suppression of Normal Flora.

Fast emerging drug resistant strains,

Two or More pathogens present

But treating one only.

Growing problems with

Immune deficiencies,Diabetus.

Failed Response (Cont ) Treating non infectious disorders with Antibiotics eg Autoimmune disorders. Slow Responses Osteomyletis,Endocarditis, Slow responding microbes, Staphylococcus, Fungal Mycobacterial infections. Fast Responders Viridians Streptococci.

Treating non infectious disorders with

Antibiotics eg Autoimmune disorders.

Slow Responses

Osteomyletis,Endocarditis,

Slow responding microbes,

Staphylococcus, Fungal

Mycobacterial infections.

Fast Responders Viridians Streptococci.

Estimation of Antibiotic Levels. Important on prolonged usage. e.g. Amino glycosides,Flucytosine, In all cases of altered clearance. (Renal Diseases.)

Important on prolonged usage.

e.g. Amino glycosides,Flucytosine,

In all cases of altered clearance. (Renal Diseases.)

Duration of Antibiotic Therapy. No specified guidelines in Major Infections. Author variation is wide Controversial. Most Important. Effective clinical response. Eg Clinical laboratory parameters in UTI Location of infection Endocarditis,Osteomyletis.

No specified guidelines in Major Infections.

Author variation is wide Controversial.

Most Important.

Effective clinical response.

Eg Clinical laboratory parameters in UTI

Location of infection

Endocarditis,Osteomyletis.

Oral or Parental Route Note Oral Antibiotic therapy is equal to parental therapy. Oral Drugs now have excellent Bioavailability.

Note

Oral Antibiotic therapy is equal to parental therapy.

Oral Drugs now have excellent Bioavailability.

Advantages of Oral therapy. Less expensive. Early discharge from Hospital. Reduction in Health care costs. Avoid Chemical phlebitis. Eliminate I,V line infections. It is proved that I.V offers no advantage than oral therapy, except in critically ill. A sense of security in patients.

Less expensive.

Early discharge from Hospital.

Reduction in Health care costs.

Avoid Chemical phlebitis.

Eliminate I,V line infections.

It is proved that I.V offers no advantage than oral therapy, except in critically ill.

A sense of security in patients.

Most prominent oral Antibiotics. Doxycycline, Clindamycin. Metronidazole. Levofloxacin. Chloramphenicol. TMX-SMX. Acyclovir. Fluconazole. Linezolid.

Doxycycline,

Clindamycin.

Metronidazole.

Levofloxacin.

Chloramphenicol.

TMX-SMX.

Acyclovir.

Fluconazole.

Linezolid.

New Uses of Old Antibiotics. Still useful on many occasions. eg Doxycycline in Malaria. Chloramphenicol – VRE.

Still useful on many occasions.

eg Doxycycline in Malaria.

Chloramphenicol – VRE.

Role of Newer Antibiotics. Do not come to prompt conclusions. Consider- 1. Cost. 2 .Resistance potential. 3.Years of use. 4.Side effects. 5.Compare with current popular drugs. 6.Consider the profile of last 2 years usage.

Do not come to prompt conclusions.

Consider-

1. Cost.

2 .Resistance potential.

3.Years of use.

4.Side effects.

5.Compare with current popular drugs.

6.Consider the profile of last 2 years

usage.

New Facts on Antibiotic Resistance. Drug resistance Not related to 1.Volume of use. 2.Years of Use. 3.Class of Antibiotics eg Cephalosporin's. But agent specific. Ceftazidime.

Drug resistance

Not related to

1.Volume of use.

2.Years of Use.

3.Class of Antibiotics

eg Cephalosporin's.

But agent specific.

Ceftazidime.

New Uses of Older Antibiotics. > 1980 Beta lactum / Quinolones. Dominates the Antibiotic prescriptions.

> 1980 Beta lactum / Quinolones.

Dominates the Antibiotic prescriptions.

Less Commonly Used, Doxycycline, Minocycline, Clindamycin, TMP-SMX Nitrofurantoin.

Doxycycline,

Minocycline,

Clindamycin,

TMP-SMX

Nitrofurantoin.

Tetracycline and related. Doxycycline,Minocycline, Can be used as first line Drugs in Atypical pneumonia, Chronic Bronchitis, Leptospirosis, Non gonococcal urethritis, C.trachomatis, Syphilis,Leptospirosis ( Penicillin Allergy )

Can be used as first line Drugs in

Atypical pneumonia,

Chronic Bronchitis,

Leptospirosis,

Non gonococcal urethritis,

C.trachomatis,

Syphilis,Leptospirosis ( Penicillin Allergy )

Trimethoprim-Sulfamethoxazole Broad spectrum – Inexpensive. Still useful in, H.influenzae, Moraxella, E.coli. Proteus mirabilis, K.pneumoniae, Shigella, E.coli ( E.T ) Toxoplasmosis MRSA ( some )

Broad spectrum – Inexpensive.

Still useful in,

H.influenzae,

Moraxella,

E.coli.

Proteus mirabilis,

K.pneumoniae,

Shigella,

E.coli ( E.T )

Toxoplasmosis

MRSA ( some )

Clindamycin. Serious Anaerobic infections. Polymicrobial osteomyletis. Infections associated with Diabetic foot. Don't Cross into CSF.

Serious Anaerobic infections.

Polymicrobial osteomyletis.

Infections associated with Diabetic foot.

Don't Cross into CSF.

Metronidazole. Anaerobic bacterial infections, Protozoal infections. Anaerobic brain abscess. H.pylori. Clostridium difficile,

Anaerobic bacterial infections,

Protozoal infections.

Anaerobic brain abscess.

H.pylori.

Clostridium difficile,

Chloramphenicol. Pneumococcal infections., Meningococcal infections. H.influenzae, Anaerobic activity, VRE Enterococcus,,

Pneumococcal infections.,

Meningococcal infections.

H.influenzae,

Anaerobic activity,

VRE Enterococcus,,

Rationalism on use of Newer Antibiotics Do not choose in Hurry, Should posses unique attributes, At least 2 years of experience before a routine choice, Many newer formulations have less side effects and improved tolerability.

Do not choose in Hurry,

Should posses unique attributes,

At least 2 years of experience before a routine choice,

Many newer formulations have less side effects and improved tolerability.

Conclusion Antibiotics are life saving pearls, Let use them precisely, wisely to a appropriate situation Dr.T.V.Rao.M D.