Antimicrobial Chemotherapy Flashcards
What are the seven principles of prescribing?
- Indications for antimicrobials
- Making a clinical diagnosis
- Patient characteristics
- Antimicrobial selection
- Regimen selection
- Liaison with laboratory
- Antimicrobial stewardship
What are the two indications for using antimicrobials?
- Therapy (to treat)
- Prophylaxis (to prevent)
What is empiric therapy?
Treatment without microbiology results.
What is directed therapy?
Treatment based on microbiology results.
What is the difference between primary and secondary prophylaxis?
Primary prophylaxis prevents a patient from getting an infection in the first place, whereas secondary prophylaxis prevents a second episode of infection.
Which patient characteristics may affect prescribing? (6)
- Age
- Renal function
- Liver function
- Immunocompromised
- Pregnancy
- Known allergies
What is the mechanism of action of bactericidal antimicrobials?
They act on the cell wall to kill the organism.
What is the mechanism of action of bacteriostatic antimicrobials?
They inhibit protein synthesis to prevent colony growth.
What are the advantages of using single drug therapy? (3)
- Simpler
- Fewer side effects
- Fewer drug interactions
What are the indications for using combination therapy? (3)
- HIV and TB
- Severe sepsis
- Mixed organisms
What are the indications for administering a drug orally? (5)
- Patient not vomiting
- Normal GI function
- No shock
- No organ dysfunction
- Adequate oral bio-availability (how much drug is absorbed)
What are the indications for administering a drug intravenously? (2)
- Severe/deep-seated infection
- When oral route is not reliable (i.e. due to impaired GI function, vomiting, etc)
What are common adverse effects of drugs? (11)
- Allergic reactions
- GI symptoms
- Candida infection (thrush)
- Liver toxicity
- Renal toxicity
- Ototoxicity
- Optic neuropathy
- Convulsions
- Peripheral neuropathy
- Bone marrow toxicity
- Megaloblastic anaemia
How would an immediate hypersensitivity allergic reaction manifest itself?
Anaphylactic shock
In what ways could a delayed hypersensitivity allergic reaction manifest itself? (5)
Maculopapular rash Drug fever Serum sickness Erythema nodosum Steven-Johnson syndrome
What are the roles of the laboratory in influencing antimicrobial use? (3)
- Carrying out culture/direct detection/serology of appropriate specimens
- Sending out results (preliminary, sensitivity, final)
- Monitoring disease activity and therapeutic level of drug
What is antimicrobial stewardship?
Making the best use of our current antimicrobials.
How is antimicrobial stewardship achieved? (3)
- Antimicrobial guidelines and policies
- Audit of quality of antimicrobial prescribing
- Education
What are the classes of antimicrobials? (10)
- Penicillins (beta-lactams)
- Cephalosporins (beta-lactams)
- Aminoglycosides
- Macrolides
- Quinolones
- Glycopeptides
- Other antibiotics
- Antifungals
- Antivirals
- Immunoglobulin
What are the three mechanisms of action of antibiotics?
- Inhibition of cell wall synthesis
- Inhibition of protein synthesis
- Inhibition of nucleic acid synthesis
Which classes of antibiotics work by inhibiting cell wall synthesis?
Glycopeptides and beta-lactams (penicillins and cephalosporins)
