Antibiotics for UTI (Staudinger)

Question 1

What are common causes of adult male UTIs?

Answer 1

Prostatitis, Epididymitis, Orchitis, Pyelonephritis, Cystitis, Urethritis, Urinary catheters

Question 2

Why is Imipenem and Cilastatin commonly used in combination to treat male UTIs?

Answer 2

Imipenem is a carbapenem which is a cell wall synthesis inhibitor. Cilastatin is a renal peptidase inhibitor.

DHP-1 enzyme found in the kidney rapidly degrades imipenem. Cilastatin combined with IV imipenem protects it from degradation.

Question 3

What are the first line drugs commonly recommended for simple UTIs in males?

Answer 3

Cephalexin
Ceftriaxone
Ampicillin
Amoxicillin
Trimethoprim/Sulfamethoxazole
Fosfomycin
Nitrofurantoin

Question 4

Cephalexin

Answer 4

1st generation cephalosporin (cell wall synthesis inhibitor) used to treat simple UTIs in males

Question 5

Ceftriaxone

Answer 5

3rd generation cephalosporin (cell wall synthesis inhibitor) used to treat simple UTIs in males

Question 6

What are the two main advantages of cephalosporins compared to penicillins when treating simple UTIs in males?

Answer 6

1. they are more resistant to beta-lactamases
2. the new R group adds chemical versatility for future development of new antibiotics

Question 7

Ampicillin and Amoxicillin

Answer 7

Aminopenicillins (broad spectrum) cell wall synthesis inhibitors used to treat simple UTIs in males

Question 8

MOA of Trimethoprim/Sulfamethoxazole

Answer 8

They are folic acid synthesis inhibitors. Sulfanamides block the first step (production of dihydropteroic acid) and trimethoprim blocks the last step (production of tetrahydrofolic acid).

Question 9

What organisms does Trimethoprim/Sulfamethoxazole cover?

Answer 9

many gram-negative and gram-positive bacteria, but NO anaerobic coverage, some protozoan coverage

Question 10

What are the warnings of Trimethoprim/Sulfamethoxazole usage?

Answer 10

Serious liver problems
Serious hypoglycemia (low blood sugar)
Pregnancy (fetal harm)
Serious skin reactions
Kernicterus in neonates

Question 11

What organism accounts for 80% of simple (uncomplicated) UTIs in males?

Answer 11

E. coli (usually resistant to ampicillin, trimethoprim and fluoroquinolones)

Question 12

Nitrofurantoin

Answer 12

First choice agent for simple (uncomplicated) UTIs in males. Resistance to nitrofurantoin is RARE; watch for adverse effects in older patients.

MOA- Damages bacterial DNA (the reduced form is highly reactive) creates multiple reactive intermediates that attack macromolecules within the cell.

Question 13

MOA of Nitrofurantoin

Answer 13

Damages bacterial DNA (the reduced form is highly reactive) creates multiple reactive intermediates that attack macromolecules within the cell.

Multiple MOAs is likely responsible for the low development of bacterial resistance.

Question 14

What is the first choice agent for simple (uncomplicated) UTIs in males due to resistance issues?

Answer 14

Nitrofurantoin. First choice agent for simple (uncomplicated) UTIs in males. Resistance to nitrofurantoin is RARE; watch for adverse effects in older patients.

Question 15

When is nitrofurantoin contraindicated?

Answer 15

In patients with known G6PD deficiency (hemolytic anemia) and in patients with chronic renal insufficiency

Question 16

Fosfomycin

Answer 16

MOA binds covalently (Cys-115) and deactivates bacterial MurA enzyme. The first step of bacterial cell wall synthesis is disrupted. Reduces bacterial adhesion in the urinary epithelial cells.

Question 17

What agents are recommended for severe UTIs in males?

Answer 17

Fluoroquinolones such as Ciprofloxacin and Levofloxacin (not recommended for simple UTIs)

Question 18

What agents are recommended for complicated UTI or kidney infections?

Answer 18

Fluoroquinolones such as Ciprofloxacin and Levofloxacin (not recommended for simple UTIs)

Question 19

Balanitis

Answer 19

inflammation of the glans penis. Commonly caused by Candida spp. Treated with Clotrimazole, Miconazole or Nystatin for allergy or sensitivity to imidazole compounds.

Question 20

What agent is used for balanitis if anaerobes are the causative agents?

Answer 20

Metronidazole
Amoxacillin/Clavulanate (Augmentin)

Question 21

What agent is used for balanitis if staph or strep are the causative agents?

Answer 21

Mupirocin (Bactroban) - topical antibiotic in the carboxylic acid class that works by blocking a bacteria’s ability to make protein

Question 22

What agents are used in a more severe case of balanitis?

Answer 22

Cephalexin
Clindamycin