1. Use of antibiotics

2. Antibiotic use
Antimicrobials are the 2nd most common drugs prescribed by office based physicians
In USA1992:
110 million oral antimicrobial rx written by office based physicians
annual antimicrobial drug use rate
= 439 /1,000 populaation

3. A 21 year old university student presents with fever , body aches , and sore throat.
A 54 year old lady complains of dysuria , frequency, loin pain and fever.
A 36 year old man presents with cough , sputum , shotness of breath and fever

4. Indications for use : Definite or probable bacterial infection
Serious infections
NOT FEVER

5. Where is the focus of infection ?
Clinical assessment
Gram stain & cultures

6. What is the likely organism :
focus of infection
gram stain
patients age
epidemiological setting
prior culture data

7. What is the commonest cause of :
urinary tract infection
cellulitis
billiary infection
meningitis
septic arthritis
nosocomial pneumonia

8. After 48 hours – check culture results
> Narrow antibiotic coverage
>Infection vs colonization

9. Other factors for antibiotic selection :
culture results
tissue penetration
bactericidal vs static
renal disease
liver disease
pregnancy & lactation

10. Antibiotics excreted mainly by kidney
Antibiotics excreted mainly by liver
Antibiotics safe in pregnancy

11. Dosing of antibiotics depends on :
MIC
half life of drug
patient factors
Duration of therapy :

12. Antibiotic combinations
Indications :
Sepsis of unclear etiology
Febrile neutropenia
Prevent emergence of resistance
Polymicrobial infection
Synergy
Disadvantages:
Elimination of normal flora
Colonisation by resistant organisms
Drug toxicity
Cost

13. Failure of therapy
Patient factors
Drug factors
Organism factors

14. History of resistance

15. INCREASING ANTIBIOTIC RESISTANCE

16. Antibiotic Resistance
Current problems with antibiotic resistant bacteria include:
MRSA
37% of all bloodstream isolates of S. aureus are now MRSA
resistance in respiratory pathogens
2.2% of S. pneumoniae are penicillin-resistant
~15-20% of H. influenzae are amoxicillin-resistant

17. Antibiotic Resistance
multi-resistant Gram-negative bacilli
extended-spectrum β-lactamase producers
glycopeptide-resistant enterococci
21.6% of bloodstream isolates of E. faecium
3.3% of E. faecalis
MDR-TB
6.2% of M. tuberculosis isoniazid-resistant
1% are true MDR strains

18. Stop Antimicrobial Treatment
When infection is treated
When infection is not diagnosed
When infection is unlikely

19. Hospital Control: Monitor
2-Monitor and evaluate empiric, therapeutic & prophylactic use
prescriptions include type of rx: E/T/P
Time limits
Empiric: 3 days
Prophylactic: 2 days
Therapeutic: 7 days
extension requires justification written by the prescribing physician
requiring MD to justify prescriptions  proper usage.

21. Hospital Control: Restrict
3-Restriction of Drugs classified as:
Uncontrolled: available for rx by all physicians
Monitored: available but usage monitored through system
Restricted: available only after consultation with ID specialist or limited list of MD