Miscellaneous and urinary antiseptics:

Question 1

Metronidazole

- spectrum of activity?

Answer 1

• Antimicrobial, amebicide and antiprotozoal
• activity against anaerobic bacteria (including bactrioides and clostridium)
• bactericidal

Question 2

Metronidazole MOA?

• what conditions are needed for optimal activity
• what pocess does it disrupt and how?

PK?

Answer 2

• Anaerobic conditions are vital for optimal activity!
• undergoes reductive bioactivation of its nitro group by ferredoxin.
• Forms cytotoxic products that interfere w/ nucleic acid synthesis

PK: Oral, IV, rectal, topical

• Wide spread distribution (including CSF)
• Elimination = hepatic metabolism

Question 3

Metronidazole Clinical applications:

Answer 3

Clostridium difficille infections
Anaerobic or intrabdominal infections (clindamycin above diaphragm)
Vaginitis
H. pylori eradication (in combo)
Brain abscesses (bothe metro and clindamycin)

Question 4

Metronidazole AE:

Answer 4

• GI irritation, stomatitis, peripheral neuropathy (prolonged use)
• Headache, dark coloration of urine
• Leukopenia, dizziness, ataxia (rarer)
• Opportunistic fungal infections
• Disulfiram-like effect (metallic taste-avoid alcohol)
• Use not allowed in first trimester

Question 5

Urinary antiseptics?

what’s their use limited to?

Answer 5

• Oral agents w/ antibacterial activity in urine but little or no systemic effect
• Use is limited to prophylaxis and treatment or lower UTI’s***

Question 6

Nitrofurantoin

• Spectrum of activity?
• MOA

Answer 6

• Bacteriostatic and bactericidal
• Active against many Gram-positive and Gram-negative bacteria

MOA: Reduction of nitrofurantoin by bacteria in the urine produces reactive intermediates that subsquently damage bacterial DNA.
- slow emergence of resistance and no cross-resistance!

Question 7

Nitrofurantoin CI, AE and PK ?

Answer 7

PK: Rapid elimination
AE: anorexia, nausea and vomiting
- Neurpathies, hemolytic anemia (G6PD defecient patients)

CI: significant renal insufficiency

• pregnancy at term (38-42 weeks)- dangerous post 38wks.
• Infants