UTIs

Question 1

Methenamine

Answer 1

Methanamine is hydrolyzed to Ammonia & Formaldehyde in Acidic urine
Formaldehyde is antibacterial against G +ve & -ve
Mandelic Acid & Hippuric Acid with which methanamine is combined, provide supplementary action

Spectrum: G-ve & G+ve
Enterobacter, klebsiella, Proteus, P. aeroginosa S aureus)

Indication: UTIs treatment and prevention

Side effects: Nausea Vomiting, diarrhea, UT irritation, skin rash

Interaction: Alkalizing agents, antagonist Acetazolamide

Question 2

Nitrofurantoin

Answer 2

Mech: bacteriostatic high conc. Bactericidal in high
Presumably disrupts bacterial enzyme system

Spectrum: G-ve & +
E. Coli, S aureus, Proteus, Enterobacter, Klebsiella

Indication: UTI prevention and treatment

Side effects: GI distress , common
Hypersensitivity (involves vital organs lungs, liver skin blood)
Adverse CNS effects (headache, vertigo, dizzy, polyneuropathy in high dose or renal impairment)

Interactions:
Absorption decrease by Mg Antacids
Plasma level increase by sulfinoyrazone
Increased toxicity by Probenecid

Question 3

Quinolones gen 1

Answer 3

Read in FQs

Question 4

Fosfomycin Tromethamine

Answer 4

Mechanism: bactericidal, inhibits cell wall synthesis
Inactivation of enzyme ENOLPYRUVYL TRANSFERASE
thereby blocking condensation of urine diphosphate N acetylglicosamine with p enolpyruvate . (1st step in synthesis)

Indication: uncomplicated UTIs (cystitis) in women by E coli E faecalis