Antibiotic Treatments for common infections

Question 1

Empirical Treatment: Hospital Acquired Pneumonia

Answer 1

IV Amoxicillin + Metronidazole + Gentamicin

Question 2

Empirical Treatment: Community Acquired Pneumonia

Answer 2

CURB65 0-2: Amoxicillin PO/IV (Doxycycline if allergic)

CURB65 3-5: Co-Amoxiclav IV + Clarithromycin IV (IV Levofloxacin if penicillin allergic)

Question 3

Empirical Treatment: Acute COPD Exacerbation

Answer 3

Amoxicillin or Doxycycline (if allergic)

Question 4

Empirical Treatment: Post OP Pneumonia

Answer 4

More than or Equals to 5 days in hospital: Treat as HAP

Less than 5 days in hospital: Amoxicillin

Question 5

Empirical Treatment: Acute Endocarditis

Answer 5

IV Flucloxacillin + Gentamicin

Question 6

Empirical Treatment: Subacute Endocarditis

Answer 6

IV Benzylpenicilin + Gentamicin

Strep viridans is the most common causative agent of subacute endocartitis, hence the choice

Question 7

Empirical Treatment: Prosthetic Valve/Suspected MRSA

Answer 7

IV Vancomycin + Gentamicin + PO Rifampicin

Both MRSA and Staph Epidermidis have similar antibiotic susceptibility

Question 8

Fever, Cough, Rusty Brown Sputum, sputum culture shows draughtsmen colonies, Urea 7mmol, BP 90/60, MSQ 8

Answer 8

IV Co-Amoxiclav + IV Clarithromycin (Levofloxacin if pen. allergic)
As per CAP guidelines; treatment is based on CURB65 SCORE
Strep. pneumoniae pneumonia

Question 9

Gram +ve, alpha-haemolytic cocci chains isolated from blood culture for patient with endocarditis

Answer 9

IV Benzylpenicillin + IV Gentamicin

Strep viridans is the causative agent

Question 10

Gram +ve, gamma-haemolytic cocci chains isolated from blood culture for patient with endocarditis

Answer 10

IV Amoxicillin + IV Vancomycin

Either Enterococcus faecalis/faecium is the causative agent

Question 11

MRSA Endocarditis

Answer 11

IV Vancomycin + IV Gentamicin

Question 12

Vomit + Watery diarrhoea after visiting chinese restaurant

Answer 12

Oral/IV re-hydration, no antibiotics required

Bacillus cereus, fried rice syndrome

Question 13

4Cs that predispose to pseudomembraneous colitis

Answer 13

Cephalosporins, Clindamycin, Co-Amoxiclav, Ciprofloxacin (Fluoroquinolones)
Typically broad-spectrum antibiotics

Question 14

Vomit + Bloody diarrhoea after Co-amoxiclav treatment

Answer 14

PO Metronidazole if mild, PO Vancomycin +/- IV Metronidazole if severe or with co-mobidity , or even stool replacement
(Clostridium difficile is the causative agent)

Question 15

Legionella pneumonia

Answer 15

Clarithromycin + Levofloxacin (some say + rifampicin instead)
Legionella spp are gram -ve and are resistant to beta-lactams

Question 16

Mucoid sputum + cough +/- fever in patient with known bronchiectasis

Answer 16

IV Gentamicin/Tobramycin + Ceftazidime OR
IV Meropenem/Piperacillin + Tazobactam
(Pseudomonas aeruginosa / Burkholderia cepecia most likely causative agent)

Question 17

Acute Epiglottis

Answer 17

Ceftriaxone

Haemophilus influenzae is the most common cause of acute epiglottis

Question 18

COPD exacerbation

Answer 18

Amoxicillin or Doxycycline as per guidelines

Haemophilus influenzae most common cause

Question 19

Cough + sputum + fever, Gram -ve bacillus grown on chocolate agar, Urea 7mmol, MSQ 8

Answer 19

PO/IV Amoxicillin (Doxycycline if pen. allergic, IV Clarithromycin if pen. allergic + IV required)
(Haemophilus influenzae is the causative agent, as per CAP guidelines for CURB65 = 2)

Question 20

Empirical Treatment: Peritonitis

Answer 20

IV Amoxicillin + Metronidazole + Gentamicin (Vancomycin if pen. allergic)

Question 21

Empirical Treatment: Intra-abdominal Sepsis

Answer 21

IV Amoxicillin + Metronidazole + Gentamicin (Vancomycin if pen. allergic)

Question 22

Culture Negative Endocarditis, work with farm animals

Answer 22

PO Doxycycline + PO Hydroxychloroquine

Coxiella Burnetii is the most likely causative agent

Question 23

Cough + Fever + Sputum + slight jaundice, work with farm animals

Answer 23

Doxycycline or Co-trimoxazole
(Empirical therapy for CAP likely to be not effective, Coxiella Burnetii is the most likely causative agent to cause Q fever + Q fever hepatitis)

Question 24

Pneumonia in HIV patients

Answer 24

Co-trimoxazole + Anti-retroviral

Pneumocystis jirovecii is the most likely causative agent. Anti-retroviral to improve immune system

Question 25

Cough + sputum + low-grade fever + Lobar consolidation in CXR, patient well enough to work and did not even realise chest infection

Answer 25

Doxycycline or Clarithromycin
(Walking pneumonia here, Mycoplasma pneumoniae is the likely causative agent. CAP guidelines will not work since M. pneumoniae is resistant to beta-lactams)

Question 26

Bird farmer came in with increasing breathlessness over 8 months, now with cough + fever

Answer 26

Doxycycline or Clarithromycin
(Chlamydophila psittaci is mostly likely the causative agent. Patient most probably developed pneumonia on top of extrinsic allergic alveolitis)
However, Pseudomonas and Burkholderia could be the cause of pneumonia if allergic alveolitis has progressed to fibrosis

Question 27

Campylobacter food poisoning

Answer 27

Usually self-limiting, Ciprofloxacin or Erythromycin if required

Question 28

Food poisoning + Dysentry + Negative stool culture

Answer 28

Check Haemolytic Uremic Syndrome
If HUS: No antibiotics, No NSAIDS, No anti-motility agents, supportive treatment + IV Fluids
E. coli O157 or Shigella spp likely to be causative agent if dysentry present
Check stool for Verotoxin

Question 29

H. pylori eradication regime

Answer 29

PPI with amoxicillin + clarithromycin (Metronidazole if pen. allergic)

Question 30

Expanding ‘Bullseye’ rash + fatigue + flu-like symptoms

Answer 30

Lyme’s disease (spread by ticks)

Question 31

Post-influenza pneumonia

Answer 31

Staph aureus most likely