Infectious diseases

Question 1

Define empiric therapy (the most common form of therapy)

Answer 1

Initiated before microorganism is identified of documented.
It depends on
•Patient history
•Physical exam
•knowledge of most likely organism
•antibiogram- susceptibility results

Question 2

Define definitive therapy

Answer 2

Initiated after establishment of infection
microorganism is known
follows culture and sensitivity results

Question 3

How do you confirm the presence of an infection

Answer 3

•History taking
•Physical exam
•Presence of fever
•Site of infection
•Predisposing factors
•Signs and symptoms
•Diagnosis with scales and stuff

Question 4

Which drugs cause medicine induced fever and how can it be ruled out?

Answer 4

Rule out by discontinuing the drug and monitoring the patient’s temperature
E. g anticholinergics, cocaine, penicillin, amphotericine B

Question 5

WBCs can communicate infection. Which ones mean what?

Answer 5

•Neutrophils: Elevated is bacterial infection
•Lymphocytes: TB, fungal or viral infections
•Eosinophils: allergic reaction
Presence of neutrophils in spinal fluid, sputum or urine is highly suggestive of bacterial infection

Question 6

How do you identify a pathogen?

Answer 6

•Collection of specimen BEFORE initiating antimicrobial therapy
•Gram staining/acid fast stain for mycobacteria or actinomycetes
•Serological tests (antigens and antibodies)
•Culture and sensitivity to assess susceptibility
•Blood culture (if acutely febrile)
•Fluid aspiration (from abscess, cellulitis)

Question 7

What is antimicrobial therapy dependant on

Answer 7

•Most likely pathogen
•Severity of infection
•Acuity of disease
•Host factors
•Med-related factors
•Need for combo therapy
•Prior knowledge of infection
•Previous antimicrobial use and response
•Site of infection
•Antibiogram+ resistance patterns

Question 8

What happens when metronidazole is taken with alcohol

Answer 8

Disulfiram reaction (vertigo, hypotension, reflex tachycardia)

Question 9

Reasons for combined therapy

Answer 9

•Broaden spectrum of activity in empiric therapy
•Prevent emergence of resistance
•Achieve synergistic activity against infecting organisms (work together e.g clindamycin with cefixime, HRZES)
•Polymicrobial infections

Question 10

Disadvantages of combo therapy

Answer 10

•Expensive
•high risk of ADRs and toxicity
•Up resistance e. g candida albicans
•Antagonistic effects
•Delayed therapy may lead to treatment failure/resistance

Question 11

What parameters are monitored in antibiotic use?

Answer 11

•Resolve infection signs and symptoms
•Improve GIT our Respiratory function
•Desired therapeutic outcomes
•ADRs of drugs e. g aminoglycosides and nephrotoxicity

Question 12

When is a patient switched from parenteral to oral?

Answer 12

•No fever over 24hrs
•Lower WBCs
•Functional GIT and respi
•Good oral bioavailability (e.g metronidazole, linezolid,levofloxacin,clindamycin,cotrimoxazole)
•

Question 13

What evasive strategies have microorganisms developed

Answer 13

•Efflux pump
•Betalactamase production
•Altering target protein
•alter membrane permeability

Question 14

What strategies help prevent resistance?

Answer 14

•Rational use
•Combo therapy
•Good hygiene
•Targeted therapy

Question 15

Inadequate response to antibiotic therapy may be due to

Answer 15

1. Wrong diagnosis
2. Inadequate concentrations
3. Non-adherence
4. Immunocompromised
5. Presence of foreign body/abscess
6. Antimicrobial resistance