Download Rational prescription of antibiotics

Rational Prescription
of
Antimicrobial Agents
Farjam MD PhD
FUMS
Inappropriate use of antibiotics
is a worldwide problem
More than 50% of all medicines are prescribed, or sold
inappropriately, and half of all patients fail to take
medicines correctly.
The overuse, underuse or misuse of medicines harms
people and wastes resources.
More than 50% of all countries do not implement basic
policies to promote rational use of medicines.
In developing countries, less than 40% of patients in the
public sector and 30% in the private sector are treated
according to clinical guidelines.
Antibiotic Resistance: importance
1. Financial loss
2. Increase morbidity
3. Increase mortality
3
Campaign to prevent antibiotic
resistance
1. Development of new antibiotics
4
Campaign to prevent antibiotic
resistance
1. Development of new antibiotics
2. Prevention of infections
6
“The more you use, the more you lose”
7
‫درصد نسخ بيمه اي حاوي حداقل يک قلم آنتي بيوتيک در سالهاي ‪،80‬‬
‫‪ 81‬و ‪ 82‬در استان فارس‬
‫‪50%‬‬
‫‪40.19%‬‬
‫‪40.68%‬‬
‫‪41.80%‬‬
‫‪1382‬‬
‫‪1381‬‬
‫‪1380‬‬
‫‪45%‬‬
‫‪40%‬‬
‫‪35%‬‬
‫‪30%‬‬
‫‪25%‬‬
‫‪20%‬‬
‫‪15%‬‬
‫‪10%‬‬
‫‪5%‬‬
‫‪0%‬‬
‫(تا پايان آذرماه)‬
‫‪8‬‬
Campaign to prevent antibiotic
resistance
1. Development of new antibiotics
2. Prevention of infections
• Hygiene measures: education and regulations
for health care workers; public education
9
Facts: Microbes can spread from
person-to-person; patient-topatient & from health care
personnel-to-patients
Maneuvers to prevent these
transmissions are the easiest &
most cost-effective actions
“Gentlemen, wash your
hands”
Chlorinated lime hand antisepsis
Ignaz Philipp Semmelweis
(1818-65)
Campaign to prevent antibiotic
resistance
1. Development of new antibiotics
2. Prevention of infections
• Hygiene measures: education and regulations
for health care workers; public education
• Vaccination
13
Campaign to prevent antibiotic
resistance
1. Development of new antibiotics
2. Prevention of infections
3. Improvement of academic education
• Improvement of clinical knowledge and
skills of medical sciences students
• Teaching (theoretical, practical) rational
selection of antibiotics
14
Campaign to prevent antibiotic
resistance
1. Development of new antibiotics
2. Prevention of infections
3. Improvement of academic education
4. Improvement of physicians’ capability to
diagnose and treat infections
Continuous medical education
• Well equipped laboratories
•
15
Campaign to prevent antibiotic
resistance
Development of new antibiotics
2. Prevention of infections
3. Improvement of academic education
4. Improvement of physicians’ capability to diagnose and treat
infections
1.
5. Education and regulations to avoid
unnecessary invasive procedures &
irrational drug prescription
16
•
Organizing expert committees in hospitals
Campaign to prevent antibiotic
resistance
1.
2.
3.
4.
5.
Development of new antibiotics
Prevention of infections
Improvement of academic education
Improvement of physicians’ capability to diagnose and treat infections
Education and regulations to avoid unnecessary invasive
procedures & irrational drug prescription
•
Organizing expert committees in hospitals
6. Continuous research, inform specialists and
17
community about the current situation and the
results of modulations
18
Antimicrobial Therapy protocol
Formulate a clinical diagnosis of microbial
infection
Obtain specimens for laboratory examination
(if recommended, if possible)
Formulate a microbiological diagnosis
Determine the necessity for empiric therapy
Empiric Therapy
Recommended in:
Well defined microbial cause
Unable to get a suitable specimen
Dangerous conditions
Empiric therapy
Antimicrobial Therapy protocol
Formulate a clinical diagnosis of microbial infection
Obtain specimens for laboratory examination
Formulate a microbiological diagnosis
Determine the necessity for empiric therapy
Institute treatment
Efficacy
23
Microorganisms & Effective
Antibiotics
Age
Efficacy
Dosage
form
Patient
condition
Check:
Iran drug lists
Iran drug information handbooks & text books
http://fdo.behdasht.gov.ir/
25
Efficacy
Age
Dosage
form
Pregnancy
Patient
condition
26
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Patient
condition
28
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Infection
site
Patient
condition
30
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Infection
site
Drug
allergy
Patient
condition
Liver
32
Hepatic disease & Pharmacokinetics
Impaired drug metabolism
•Many drugs are metabolized by liver but the hepatic reserve to
metabolize drugs is very high
•No important changes in acute viral hepatitis
•Impaired metabolism in advanced chronic hepatic failure (dose
adjustment is required for some drugs)
•Note: No correlation exists between enzymes level and capacity
of of metabolism
34
Fluid overload & edema
•Exacerbation by NSAIDs, corticosteroides, …
38
Antibiotics & Liver Disease
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Infection
site
Drug
allergy
Patient
condition
Liver
Kidney
41
Renal disease & Pharmacokinetics
Important points
•RF is important for drugs that are not extensively metabolised
or have active metabolites
•Some other pharmacokinetic parameters may change in RF
•Uremia may change some pathway of drug metabolisms
•The uremia may change (increase or decrease) the effects
(desired or undesired) of some drugs
43
Antibiotics & Renal Disease
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Infection
site
Drug
allergy
Patient
condition
Liver
Kidney
Lactation
45
Antibiotics in lactation
Safe
With caution
Contraindicated
Penicillins
Cephalosporins
Eryhtromycin
Clindamycin
Tetracyclines1
Co-trimoxazole2
Nalidixic acid
Nitrofurantoin
Nystatin
Fluconazole
Azithromycin
Clarithromycin
Metronidazole
(ordinary dose)
Aminoglycosides
Fluoroquinolones
Ketoconazole
Metronidazole
(high dose)
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Infection
site
Drug
allergy
Patient
condition
Liver
Kidney
Lactation
Other
drugs
47
http://www.drugdigest.org
48
Efficacy
Age
Dosage
form
Pregnancy
Immune
system
Infection
site
Drug
allergy
Patient
condition
Liver
Kidney
Lactation
Other
drugs
Adverse
effects
49
Adverse Reactions & Drug Interactions
Efficacy
Age
Dosage
form
Immune
system
Pregnancy
Infection
site
Drug
allergy
Patient
condition
Liver
Kidney
Duration
of
treatment
Lactation
Using
frequency
Other
drugs
Taste &
odour
Adverse
effects
Cost
51
Appropriate use of
antibiotics in children
Considerations before
prescribing
1. Is an antibiotic necessary?
2. What is the most appropriate
antibiotic?
3. What dose, frequency, route and
duration?
4. How to improvethe chances that
the tretament will be effective?
Is an antibiotic necessary?
Useful only for the treatment of
bacterial infections
Not all fevers are due to infection
Not all infections are due to bacteria
There is no evidence that antibiotics
will prevent secondary bacterial
infection in patients with viral
infection
The treatment of certain infections
might be better achieved with other
Recommended therapy for
CA-MRSA
Infection
Severity
Choice of antibiotic
Skin/soft tissue
Mild
Topical, drainage
Moderate
Clinda, T/S, Doxycyclin
Severe
Vanco ± Clox or CephI
Osteomyelitis
Vanco, Clinda, T/S ± Rif
Pyomyositis,
necrotizing fasciitis
Vanco ± Clox or CephI
Consider Clinda, IVIG
Necrotizing
pneumonia
Vanco
Sepsis syndrome,
endocarditis
Vanco ± Clox or CephI
Consider Clinda, IVIG
Barton M et al.
Can J Infect Dis Med Microbiol 2006; 17(Suppl C): 1B-24B
Choice of antimicrobial agent
Based on three main factors:
Etiological agent
Patient-related factors
Antibiotic-related factors
Antibiotic choice:
Etiological agent
Be careful of the identification of the
agent by the laboratory
– Example: UTI
How was sample collected?
Contamination of sample is frequent,
even in the best conditions
Consider the symptoms…
Consider the urinalysis…
Antibiotic choice:
Etiological agent
Most probable agents: based on epidemiology
and clinical experience
Importance of local antibiotic resistance data
Resistance patterns vary
– From country to country
– From hospital to hospital in the same country
– From unit to unit in the same hospital
– With time
Regional/country data useful only for following
trends, NOT guide empirical therapy
Ciprofloxacin in children?
Original quinolone: Nalidixic acid
Inhibitors of DNA gyrase
Toxicity on the cartilage of immature
animals (standard preclinical model)
Never evaluated in clinical studies in
infants & children
Ciprofloxacin : Only oral agent active
against P. aeruginosa. Pneumococcus is
resistant
Hand infections
Always severe
Need close
monitoring and IV
antibiotics
Etiology:
– S. aureus and
Group-A
streptococcus
– P. multocida
– Eikenella
corrodens
Treatment of invasive cellulitis
Penicillin 250,000 U/kg/day ÷ q46hr AND
Clindamycin 40 mg/kg/day ÷ q8hr
Or
Cephalexin
cloxacillin
Choice of regimen
Oral vs parenteral
– Traditional view
« serious = parenteral »
Previous lack of broad spectrum oral
antibiotics with reliable bioavailability
– Improved oral agents
Higher and more persistent serum and
tissue levels
For certain infections as good as
parenteral
Treatment of febrile UTIs in
children
In the past: hospital-based IV therapy
– Usually Ampicillin + gentamicin
From 1995: Amoxicillin and once-daily IM
gentamicin, then oral therapy after 2-3 days
Today: Cefixime PO 8 mg/kg q12h x 2 then q24h
–
–
–
–
–
Uncomplicated UTIs
Child aged 6 months or more
Non-toxic, well hydrated
Good compliance/follow-up
No comorbidity, allergies etc.
Treatment of uncomplicated
osteomyelitis/septic arthritis
Initial IV therapy for 7-10 days in-hospital
Followed by either
– Home IV antibiotic therapy for 3-4 weeks
– Oral antibiotic: Cephalexin 100 mg/kg/day ÷
q8h for 3-4 weeks
Specific conditions apply
– With weekly supervision and 24/7 availability in
case of problems
Advantages of oral treatment
Eliminates risks of complications
associated with intravascular lines
Shorter duration of hospital stay
Savings in nursing time
Savings in overall costs
Greater patient satisfaction
In conclusion
It is an essential role of the pediatrician to ensure
that antibiotics are used appropriately
This is easy! Ask simple questions before initiating
any antimicrobial treatment.
Be systematic in your approach
Consider alternatives
Know the important facts about
– Best schedules and duration for specific infections
– New ways of using old antibiotics
– Availability of new agents and new treatment modalities