Micro 8 - UTI Flashcards
What do we see in the urine lab in cystitis?
WBC and often RBCs. Casts won’t be seen because they are only seen when the kidneys are affected.
Who are more predisposed to UTIs?
Women, males with congenital defects (hypospadias and epispadias), enlarged prostate, static urine in the bladder, diabetics, pregnant women, vesicoureteral reflux.
What are the symptoms of pyelonephritis?
Fever, chills, flank pain, hematuria, WBC casts.
What is the Nitrite test?
Test that checks for the presence of Enterobacteriaceae. It will not detect other types of bacteria causing the UTI.
What does the Leukocyte esterase test indicate?
A positive LE indicates inflammation in the urinary tract. It can also be positive when there is a gonorrhea infection.
What are the 4 most common causes of UTI?
E.coli (80%), Staph saprophyticus, Klebsiella pneumoniae, Proteus.
What is interesting about UTIs caused Proteus mirabilis and Proteus vulgarus?
They are motile and have urease, which can cause ammonium-magnesium renal stones (Staghorn calculi).
What is the treatment for UTIs?
Has to cover G(-) organisms. Use sulfonamides w/ trimethoprim, aminopenicillins, fluoroquinolones, nitrofurantoin.
What sulfonamides are used in UTIs?
Sulfamethoxazole (SMX) y sulfadiazine.
What is the mechanism of action of sulfonamides?
They are folic acid inhibitors: bacteria can produce it while humans have to absorb it from the environment. Sulfonamides are competitive inhibitors of dihydropteroate synthetase.
What are the uses of sulfonamides?
They cover some G(+) and G(-). They are used in UTIs, skin infections. It is always combined with trimethoprim (TMP-SMX).
What are the side effects of sulfonamides?
Hypersensitivity reactions, hemolysis (especially to G6PD patients), Nephrotoxicity, Kernicterus (to fetus), displace other drugs from albumin (eg. Warfarin), Steven-Johnson syndrome, and photosensitivity.
What drugs have photosensitivity reactions?
[SAT for a photo]
Sulfonamides, Amiodarone, Tetracycline.
What would be three factors that can lead to resistance of sulfonamides?
Altered dihydropteroate synthetase, decreased drug uptake, and increased PABA synthesis.
What are the drugs that can cause a sulfa allergy?
[Sulfa Pills Frequently Cause Terrible Acute Symptoms]
Sulfasalazine, Probenecid, Furosemide, Celecoxib, Thiazides/TMP-SMX, Acetazolamide, Sulfonylureas.
What are the three major categories of drugs and one outlier that can cause Steven-Johnson syndrome?
Penicillin, sulfa, and seizure drugs. The outlier is allopurinol.
What are 5 seizure drugs that can cause Steven-Johnson syndrome?
Ethosuximide, lamotrigine, carbamazepine, phenobarbital, phenytoin.
What is the mechanism of action of Trimethoprim?
It inhibits Dihydrofolate reductase
What is the mechanism of action of Methotrexate?
Inhibit Dihydrofolate reductase.
What is Cystitis and what are it’s symptoms?
Infection of the bladder, a lower urinary infection. Causes painful urination, frequency, urgency and suprapubic pain.
What is the mechanism of Nitrofurantoin?
Bacteriocidal. Reduced by bacterial proteins to a reactive intermediate that inactivates bacterial ribosomes.
When do we use nitrofurantoin?
Mild UTIs and cystitis (not pyelonephritis) by E.coli or S.saprophyticus (not Proteus). Safe in pregnancy.
What are 3 flouroquinolones used in UTIs?
Levofloxacin, ciprofloxacin, Norfloxacin.
What is the mechanism of action of fluoroquinolones?
It inhibits DNA gyrase (topoisomerase II).
What is contraindicated when taking flouroquinolones?
Antiacids and supplements (that includes Ca, Fe, or Mg).
To whom is flouroquinolones contraindicated and why? What is the one special occasion?
Contraindicated in pregnancy and children because it damages cartilage. It can cause tendonitis and tendon rupture in adults. Can be used in children with cystic fibrosis because they are predisposed to lung infections, especially to pseudomonas infections.
What is the mechanism for metronidazole?
It gets absorbed by the microorganism and forms toxic free radicals that damage the organism’s DNA.
Which organisms are susceptible to Metronidazole?
[GET GAP on the Metro]
Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobic bacteria, h.Pylori.
What is a special side effect of metronidazole?
Has a disulfram-like reaction when combined with alcohol.
What does disulfiram do?
It inhibits aldehyde dehydrogenase, leading to accumulation of aldehyde causing: flushing, sweating, nausea, headache, hypotension.
What infections is klebsiella pneumonia known for causing?
Aspiration pneumonia, lung abscesses, UTIs (nosocomial).
What is the function of the enzyme urease?
Splits urea into NH3 and CO2.
RFF: Most common medication used for UTI prophylaxis.
TMP-SMX.
RFF: Most common bacterial in a patient with struvite kidney stones.
Proteus, then Staph.
