Introduction to antimicrobials Flashcards
s. aureus can cause
enterocolitis
Candida albicans can cause
vagina, mouth (thrush)
C. difficile can cause
pseudomembranous colitis
مهمممم
risk factors for superinfection
in hospital > 6 days
6>age>60
Broad spectrum antibiotics
drugs that cannot be absorbed by GI
شو مواصفاتها وليش منعطيها
high molecular weight, highly polar
to act locally on GIT
Drugs CI in pregnancy
FAST CAT
F: fluoroquinolones
S: sulfa
C: chloramphenicol
T: tetracyclines
A: aminoglycosides
Definitive therapy
treating exactly the causative agent depending on its sensitivity test
Empiric therapy
Prophylactic therapy
giving antibiotic to prevent the spread among contacts
rifampin as Prophylactic therapy to prevent
meningococcal meningitis
Giving chloroquine to patient traveling to Africa to prevent
malaria
الملكة صابتها ملاريا
Preoperative to prevent opportunistic infections
oral neomycin in
colorectal procedure
فرصة جديدة
Neo+ opportunistic
In dental procedures to prevent bacterial myocarditis in patients with abnormal
heart valves, Recommended therapy:
2 grams of amoxicillin one hour before the procedure
50 mg\kg in children up to 2 grams
In people allergic to penicillin we give 600 mg clindamycin orally
To prevent recurrent UTI
Co-Trimoxazole
To prevent rheumatic fever with patients with recurrent tonsillitis
benzathine penicillin (1 injection monthly)
To prevent hepatic coma
oral neomycin with lactulose
Drug resistance
If the maximal tolerated dose of antimicrobial does not affect the bacterial growth
Drug resistance caused by
- Decreased accumulation
• Decreased uptake or increased efflux of an antibiotic - Enzymatic inactivation
• Such as beta-lactamases that inactivate beta-lactams antibiotics
Drug resistance prevented by
Ensure an appropriate indication, dose, duration
Restrict use of drug combination to appropriate situations
aminoglycosides toxic effect
ototoxicity
أمين أذنه بتوجعه
chloramphenicol toxic effects
aplastic anemia
الكلور بعمل فقر 🩸
Hypersensitivity vs Toxic effect
Hypersensitivity not dose related
Toxic effect Dose related
Advantages of combining antimicrobials
To delay or avoid the development of resistance
To broaden the spectrum (empiric therapy)
To obtain potentiation (synergistic effect)
synergistic effect example
using B-lactams & aminoglycosides in endocarditis
o Beta lactams will destroy the cell wall allowing the aminoglycoside to enter the
cell and act on ribosomes
بيتا بدها تكسر جدار الميكروب عشان تفتح لأمين طريق ويقدر يدخل
Co-amoxiclav
amoxicillin (antibiotic) & clavulanic acid (which is beta-lactamase inhibitor