AM - Principles of clinical use Flashcards
How do we reduce risk of growing antimicrobial resistance?
- Only prescribe them when necessary
- Use narrow spectrum
What patient characteristics must considered when choosing an AM?
Age
Renal Function
Hepatic Function
Pregnancy
Why consider age when choosing an AM?
Some are contraindicated in kids.
E.g. Ciprofloxacin can cause abnormal cartilage development
How do we adjust during renal impairment?
Scale down the drug dose proportionally to the renal insufficiency
What does the liver do to AMs?
Metabolises them & excretes them in bile
In what ways are some AMs dangerous to pregnant women?
- Mutagenic, mutate foetal chromosomes
- Teratogenic, associated with congenital abnormalities
- Or Both!
What types of prophylactic AM treatment are there?
Pre-op when theres a high risk of infection
Post-Exposure to highly communicable diseases
Whats different about a prophylactic AM treatment?
Dosage should cover just the period of risk e.g. one pre-op dose instead of a normal course of them
In what case would you commence empiracal AM therapy?
If urgent treatments needed & thers no time for culture of antibiotic sensitivity tests
In what cases is combination therapy better then monotherapy?
- If theres mixed infection
- The AMs have an enhanced effect together
- To minimise development of strains resistant to any one agent
What are the 3 possible outocomes when using 2 AMs together?
- Additive
- Antagonistic
- Synergistic
What does it mean when 2 AMs are antagonistic>?
Their combined effect is less than the sum of their individual effects
What does it mean when 2 AMs are synergistic?
Their combined effect is greater than the sum of their individual effects.
Example of syneristic antibiotics?
Penicillin & Gentamicin for Strep. infections
Examples of drugs whose serum levels must be monitored closely?
Vancomycin
Gentamicin
