Infectious Disease Flashcards
MRSA Drugs
Telavancin Dalbavancin Tedizolid Oritavancin Vancomycin Daptomycin Linezolid Ceftaroline
MSSA Drugs
FIRST LINE
IV: oxacillin, nafcillin, cefazolin
PO: dicloxacillin, cephalexin, cefadroxil
SECOND LINE
IV: any cephalosporin, any carbapenem, beta-lactam/beta-lactamase
PO: amoxicillin/clavulanate, oral cephalosporins
First line MRSA Drugs
IV: vancomycin. linezolid, daptomycin, cetaroline
PO: linezolid, TMP/SMX, doxycycline
What is the best empiric therapy for gram-positive cocci in blood cultures?
Vancomycin
Adverse effects of linezolid
thrombocytopenia
interaction with MAOIs
Adverse effects of Daptomycin
CPK (creatine kinase) elevation
Not effective for lung infections
What medications are used to treat minor MRSA infections of the skin?
TMP/SMX
Doxycycline
Clindamycin
Linezolid
What bacteria are covered by amoxicillin?
HELPS
H. influenzae E. coli Listeria Proteus Salmonella
Amoxicillin is the best initial therapy for what?
Otitis media Dental infection Endocarditis prophylaxis Lyme disease that is limited to rash, joint, or CN VII UTI in pregnant women Listeria Enterococcal infections
What are the penicillinase-resistant penicillins (PRPs)? What are they used to treat?
Oxacillin
Cloxacillin
Dicloxacillin
Nafcillin
Used to treat:
Skin infections (cellulitis, impetigo, erysipelas)
Endocarditis, meningitis, staph bacteremia
Osteomyelitis and septic arthritis when organism is sensitive
Not effective against MRSA or Enterococcus
Why is methicillin never the right answer?
It causes renal failure secondary to allergic interstitial nephritis.
What bacteria are covered by piperacillin, ticarcillin, azlocillin, mezlocillin? They are the best initial therapy for what?
Gram negative bacilli (E. coli and Proteus) from the Enterobacteriaceae group and Pseudomonas
Best initial therapy for: Cholecystitis Pyelonephritis Bacteremia Hospital acquired pneumonia Neutropenia and fever
What is the only cephalosporin that covers MRSA? What generation is it?
Ceftaroline
5th generation
Babesiosis
Babesia microti
Ixodes tick
Flu-like symptoms, ARDS, splenic rupture, DIC, CHF
Anemia, thrombocytopenia, intravascular hemolysis (jaundice, dark urine)
Elevated bilrubin, LFTs, and LDH
Diagnosis: thin blood smear showing intraerythrocytic rings – Maltese Crosses
Treatment: Atovaquone + Azithromycin, Quinine + Clindamycin if severe
Note: higher risk if immunocompromised, >50 years old, or with history of splenectomy
What illnesses are carried by the Ixodes tick?
Babesiosis, Lyme, and Human Granulocytic Anaplasmosis
How do you diagnose Babesiosis? What are the findings?
Thin blood smear
Intra-erythrocytic rings – Maltese Cross
What is the treatment for Babesiosis?
Atovaquone + Azithromycin
Quinine + Clindamycin for severe cases
Erysipelas
Strep pyogenes (Group A Strep)
Superficial dermal and lymphatics with raised and sharply demarcated edges, commonly affects the outer ear
Rapid onset and spread
Fever early in course
Treat: IV antibiotics (ceftriaxone, cefazolin) if systemic symptoms, amoxicillin if no systemic symptoms
Nocardia
Partially acid-fast, gram positive, filamentous branching rods
Immunocompromised hosts, lung nodules and brain abscesses
Lung nodules without cavitation on CXR
Treatment: TMP-SMX
HIV patient with fever, cough, abdominal pain, diarrhea, night sweats, and weight loss with exam and lab findings of splenomegaly, elevated alkaline phosphatase, and a CD4 count <50
Disseminated Mycobacterium avium complex
Prevent with azithromycin prophylaxis
Isoniazid Induced Peripheral Neuropathy
Caused by pyroxidine (B6) deficiency
Numbness and tingling in a stocking glove distribution
Mucormycosis
Risk factors: DM with DKA, hematologic malignancy, transplant
Manifestations: Acute, fever, nasal congestion with purulent discharge, headache, sinus pain
Diagnosis: necrotic invasion of the palate, orbit, and brain, sinus endoscopy with biopsies and cultures
Treatment: surgical debridement, liposomal amphotericin B
What is the treatment of mucormycosis?
surgical debridement and liposomal amphotericin B
