Lab 5 - UTI, STD, PID Flashcards
TMP/SMX - MoA
Folate antagonist, inhibits DNA synthesis
TMP/SMX - Dose and route
160mg TMP, 800mg SMX twice daily PO
Cystitis: for 3 days for women 7 days for men
Pyelonephritis: 7-10 days
Acute bacterial prostatitis: 2-4 weeks
Chronic bacterial prostatitis: 4-6 weeks, recurrence: 12 weeks
TMP/SMX - Adverse effects
Stevens-Johnsons syndrome
Crystalluria
Hematuria
Anemia, leukopenia, thrombocytopenia, megaloblastic anemia, hemolytic anemia, GI- reactions
TMP/SMX - Contraindications
Porphyria Liver and kidney failure Pregnancy Infants G6PD-deficiency
TMP/SMX - Interactions
- Additive folate deficiency with methotrexate
- Increased thiazide-induced thrombocytopenia
Ceftriaxone - MoA
Inhibits bacterial cell wall synthesis
Ceftriaxone - Dose and route
500 mg IM
Ceftriaxone - Adverse effects
Hypersensitivity (rare, cross-sensitivity to penicillins):
Anaphylaxis, fever, skin rashes, nephritis, granulocytopenia, hemolytic anemia
Local irritation: pain after IM injection, thrombophlebitis after IV
Renal toxicity (intersitial nephritis, tubular necrosis)
Ceftriaxone - Contraindications
Allergy to cephalosporings and penicillins
Newborns with jaundice or patients with hypoalbuminemia or acidosis
Ceftriaxone - Interactions
Probenecid inhibits renal secretion and increases the serum concentration
Doxycycline - MoA
Inhibits protein synthesis
Doxycycline - Dose and route
100 mg x 2 in 7 days orally
2 week treatment in PID/epididymitis, 3 weeks in LGV
Doxycycline - Adverse effects
Nausea
Vomiting
Diarrhea
Photosensitivity
Discoloration of teeth and hypoplasia of the enamel in pregnant women and childer under 8 years
Nephrotoxicity and Hepatotoxicity (increased risk in pregnant women)
Doxycycline - Contraindications
Pregnancy and children under 8
Decreased kidney and liver function
Doxycycline - Interactions
- Aminoglycosides potentiate nephrotoxicity
- Calcium and iron reduce bioavailability
Cystitis - Diagnosis
Uncomplicated cystitis: based on history; at least one symptom of UTI + absence of vaginal discharge + risk factor present –> no lab evaluation with dipstick or urine culture necessary
Urinary dipstick test: Positive Nitrite (Enterobacteriaceae converts nitrate to nitrite), Positive leukocyte esterase
Urine microscopy: Pyuria (WBC, pus), hematuria
Urine culture: 10^5 bacterial /mL, 10^3 for S. saprophytic
CRP: mild elevation in cystitis, more severe elevation in pyelonephritis
Positive goldflam’s sign in pyelonephritis
Blood culture: in case of complicated pyelonephritis, fever in CAUTI, systemic symptoms in complicated UTI, prostatitis
Men:
- Culture if symptoms of UTI. Documentation of bacteriuria can differentiate the less common acute/chronic bacterial prostatitis from very common chronic pelvic pain syndrome.
- Increased levels of prostate-specific antigen + enlarged prostate (CT, ultrasound)
- Meares-Stamey test (if diagnosis is unclear or UTI is recurrent)
Differential diagnosis when women present with dysuria
Cervicitis (C. trachomatis, N. gonorrhoeae)
Vaginitis (C. Albicans, Trichomonas vaginalis)
Herpetic urethritis, interstitial cystitis, noninfectious vaginal or vulvar irritation
UTI/ASB pregnant women + dose and route
Nitrofurantoin: 50 mg 3 times/day for 7 days PO
Nitrofurantoin - MoA
Inhibits bacterial enzymes, and damages bacterial DNA
Nitrofurantoin - Adverse effects
GI irritations (nausea, vomiting, diarrhea), pulmonary fibrosis hepatitis, hematologic toxicity
Nitrofurantoin - Contraindication
Porphyria, renal failure, anuria/oliguria, G6PD –> hemolytic anemia
Nitrofurantoin - Interactions
Probenecid inh urinary excretion.
Antacids reduce absorption
Candiduria - dose and route
200 mg/d PO 14 days
Prevention of recurrent UTI
Continuous, postcoital, patient-initiated therapy; low doses of TMP-SMX, prescribed for 6 months
Laboratory Diagnosis of Gonorrhea
Nucleic acid amplification test (NAATs) of urine sample: more sensitive than culture
Gram’s staining of urethral/cervical exudates: gram (-) mono or diplococci, PMNs seen in endocervix (presence of inflammatory discharge)
Culture: Thayer-Martin medium. All cases of gonorrhea (urethra, cervix, anus, pharynx) should be cultured.
Blood culture: gonococcal arthritis
Uncomplicated gonococcal infection - Treatment
500 mg IM Ceftriaxone + Azithromycin 2g PO
Azithromycin - MoA
Protein synthesis inhibitor
Azithromycin - Adverse effects
Stomatitis, heart burn, uncoordinated peristalsis, nausea
Azithromycin - Interactions
Al, Mg, Antacids delay absorption and decrease serum conc.
Azithromycin - Contraindication
Diarrhea, hypersensitivity to macrolides, hepatic dysfunction
Gonococcal meningitis and endocarditis - treatment
Ceftriaxone IV 1-2 g every 12-24 h 10-14 days for meningitis, 4 weeks for endocarditis
PID- treatment
Doxycycline 200 mg/d in 14 days
Ceftriaxone 250 mg IM
Metronidazole 500 mg bid 14 days
LGV - characterized by what, and differential diagnosis
Acute lymphadenitis and hemorrhagic proctitis
Differential diagnosis- Crohns disease due to giant cell formation and granulomas
Chlamydia - Diagnosis
NAAT- urine or vaginal swab (cervical swabs from symptomatic women undergoing pelvic exam)
Serology- LGV, neonatal pneumonia. Microimmunofluoresence.
Gram’s staining/culture to exclude gonorrhea
Sigmoidoscopy/biopsy in proctitis
Gonorrhea - Pregnant women
Chlamydia- Pregnant women
Ceftriaxone 500 mg IM single dose
Amoxicillin 500 mg 3 times daily PO for 7 days
Metronidazole - MoA
Tissue amebicide. Inhibits pyrovate ferredoxin oxidoreducrase (PFOR) and nucleic acid synthesis.
Metronidazole - Adverse effects
GI-irritation
Metallic taste
Transient leukopenia
Thrombocytopenia
Metronidazole - Contraindication
First trimester pregnancy
Alcohol
Metronidazole - Interactions
Disulfiram-like reaction with ethanol
Increases levels of warfarin
Serum levels affected by drugs inh/inducing cyp3a4.
