UTI Flashcards
What are the medications used for UTI
Phenazopyridine (pain analgesic)
Beta-lactam + oxapenem/aminopenicillins (Amoxicillin-Clavulanate)
2nd gen fluoroquinolones (Ciprofloxaxin)
Sulfonamides (Trimethoprim-sulfamethoxazole/TMP-SMZ/Bactrim)
Novel class (Fostomycin)
DNA synthesis inhibitors (Nitrofuratoin)
Names of Beta-lactam abx + oxapenem/aminopenicillin
Amoxicillin/Clavulanate
Name of 2nd gen fluoroquinolone
Ciprofloxacin
Name of sulfonamides
Trimethoprim-Sulfamethoxazole (TMP-SMZ/Bactrim)
Name of novel class
Fosfomycin
Name of DNA synthesis inhibitors
Nitrofurantoin
MOA of beta-lactam abx + oxapenem/amoxicillin+clavulanate
Inhibit bacterial cell wall synthesis (inhibit transpeptidation)
Why is amoxicillin/clavulanate used
For its extended spectrum action
AE of amoxicillin/clavulanate
Generally well tolerated
Rash & diarrhoea are most common AE
1-4% get allergic reaction - severe hypersensitivity that are potentially fatal (SJS)
Thrombophlebitis (inflammation @ injection site)
MOA of ciprofloxacin/2nd gen fluoroquinolones
DNA synthesis inhibitor
Why is ciprofloxacin used for
Broad spectrum action - concentration-dependent killing
Why is ciprofloxacin not used anymore as a first choice drug
Increasing resistance
AE of ciprofloxacin
Nausea, diarrhoea, vomiting, headache, restless, pain & inflammation @ injection site, anaphylaxis, tendon rupture, superinfection, photosensitivity, pseudomembrane colitis, seizure, peripheral neuropathy & hepatotoxicity
Who should not use ciprofloxacin
Elderly with tendonitis & athletes with tendon rupture
MOA of trimethoprim-sulfamethoxazole (TMP-SMZ/Bactrim)
Inhibit folate synthesis - synergistically inhibit folate synthesis (2 step process: sulfamethoxazole inhibit dihydropteroate synthase [1st step to making nucleic acid] trimethorpim inhibit dihydrofolate reductase [2nd step to making nucleic acid]) & kill bacteria effectively
Why is trimethoprim-sulfamethoxazole not used as a first choice urinary septic drug
Due to increasing resistance of drug
AE of trimethoprim-sulfamethoxazole
Nausea, vomiting, anorexia, rash, photosensitivity, crystalluria, anaphylaxis, blood dyscrasia, fulminant hepatic necrosis, hyperk, SJS
MOA of fosfomycin
Inhibit bacteria cell wall synthesis - inhibit transglycosylation
Why is fosfomycin used
Specific for urinary system
Safe for pregnant women
Can be used if pt is resistant to ciprofloxacin (fluoroquinolones)/trimethoprim-sulfamethoxazole
Can also be used in place of amoxicillin-clavulanate
AE of fosfomycin
Nausea, diarrhoea, headache, back pain, anaphylaxis, superinfection
MOA of nitrofurantoin
DNA synthesis inhibitor which disrupt nucleic acid synthesis via oxidative stress (work like metrodinazole)
Why is nitrofurantoin used
Specific coverage for UTI infections
AE of nitrofurantoin
Nausea, vomiting, anorexia, dark brown urine, anaphylaxis, superinfections, hepatic necrosis, interstitial pneumonitis, SJS
Which classes are susceptible to SJS
Nitro & sulfa groups (nitrofurantoin & trimethoprim-sulfamethoxazole)
Why are oxapenems used with beta lactam abx
To prevent beta lactam abx from being destroyed by beta-lactamase produced by bacteria (combat resistance)
Popular combinations of beta-lactam + oxapenem
Amoxicillin/Clavulanic acid or Clavulanate
Ticarcillin/Clavulanate
Pipericillin/Tazobactam
Ampicillin/Sulbactam
Which medications can be used for pregnant women
Amoxicillin & fosfomycin
What can be used to treat MRSA
Vancomycin & sulphonamides
What is the empirical treatment of pyelonephritis
IV Ceftriaxone
What is the alternative treatment for pyelonephritis
Pipericillin/tazobactam
What is the ideal pH for urinary system when taking nitrofurantoin to exert its greatest effect
5.5
What is a single dose (100mg) of nitrofurantoin good for
Prevent recurrent uncomplicated UTI in some women
What is the empirical treatment for cystitis
Nitrofurantoin
What are the alternative treatment for cystitis
Trimethoprim-sulfamethoxazole (TMP-SMZ/Bactrim)
Fosfomycin
Why is fosfomycin a less efficacious drug
Pseudomonas & Acinebacter may be resistant to it
What medication should be given to a female who got UTI for the first time without any hx of use of common abx
Amoxicillin-Clavulanate & Cotrimoxazole (trimethoprim-sulfamthoxazole)
What medication should be given to a female who has gotten recurrent UTI and has been prescribed abx before
Nitrofurantoin
What medication should be given to a pregnant lady with UTI
Fosfomycin
What mediation should not be given to a UTI patient with allergy to penicillin
Beta lactam abx
What medication should not be given to a UTI patient with allergy to sulfa
Cotrimoxazole (Trimethoprim-Sulfamethoxazole)
What medication should not be given to a UTI patient with G6PD
Cotrimoxazole (Trimethoprim-Sulfamethoxazole) & Nitrofurantoin
What medication should not be given to an elderly patient with UTI and cardiac dysrhythmia
Fluoroquinolone (Ciprofloxacin)
What to do when all treatment has failed and there is bacterial resistance
Refer to hosp guidelines & check resistance patterns
