Drugs for respiratory infections - SRS Flashcards
What are the two aminopenicillins we need to know?
Ampicillin
Amoxicillin
What are three B-lactamase inhibitors Waller listed in RED?
Ampicillin-sulbactam
Amoxicillin-clavulanic acid
Piperacillin-tazobactam
What are the third generation cephalosporins?
Ceftriaxone
Ceftazidime
What is the fourth generation cephalosporin we discussed?
Cefepime
What are the two carbapenems we covered?
Meropenem
Etrapenem
What is the glycopeptide we must know?
Vancomycin
What is the fluoroquinolone we must know?
Levofloxacin
What is the aminoglycoside we must know?
Gentamicin
What is the tetracycline we must know?
Doxycycline
What is the macrolide we must know?
Azithromycin
What is the lincosamide we must know?
Clindamycin
What is the oxazolidinone we must know?
Linezolid
What antiviral was listed in RED?
Oseltamivir
What antifungals do we need to know?
Fluconazole
Itraconazole
Voriconazole
Are B-lactams time or concentration dependent?
What is their mechanism of action?
- Time dependent
- structural analogs of D-Ala-D-Ala; covalently bind penicillin-binding proteins (PBPs), inhibit transpeptidation
What are four ADR’s associated with penicillin?
- Allergic reactions (0.7-10%)
- Anaphylaxis (0.004-0.04%)
- Nausea, vomiting, mild to severe diarrhea
- Pseudomembranous colitis
What are the ADR’s associated with cephalosporins?
- 1% risk of cross-reactivity to penicillins
- Diarrhea
What are the carbapenem ADR’s? 3
- Nausea/vomiting (1-20%)
- Seizures (1.5%)
- Hypersensitivity
MOA for Vancomycin?
- Inhibits cell wall synthesis binding with high affinity to D-Ala-D-Ala terminal of cell wall precursor units.
What are the ADR’s associated with Vancomycin?
5
- Fever, chills
- rash
- Red-Man Syndrome
- Ototoxicity
- nephrotoxicity
What is red-man syndrome and what causes it?
Extreme flushing, tachycardia, hypotension
Caused by Vancomycin induced histamine release.
What is the mechanism of action of fluoroquinolones?
- targets bacterial DNA gyrase & topoisomerase IV.
- Prevents relaxation of positive supercoils
Are fluoroquinolones concentration or time dependent?
Concentration-dependent
Fluoroquinolone ADR’s include GI disturbances such as nausea, vomiting and abdominal discomfort. What other ADR’s are associated with these antibiotics?
CNS
- headache
- dizziness
- delirium
- hallucinations (rarely)
General
- Rash
- Photosensitivity
-
Achilles tendon rupture (contraindicated in children)
-
What is the mechanism of action of aminoglycosides?
- Works on the 30S subunit to interfere with initiation
- Causes misreading and abberant protein production
What is the MOA of tetracyclines?
30S subunit- blocks aminoacyl tRNA acceptor site
MOA for both macrolides and clindamycin?
Both work on the 50S subunit to Inhibit translocation
MOA for Linezolid?
Acts at the 50S subunit to block formation of the intiation complex.
What are the ADR’s associated with aminoglycosides?
- Ototoxicity
- nephrotoxicity
- neuromuscular block
- apnea
What are the ADR’s we know of for tetracycline?
- GI disturbances
- superinfections of C. difficile
- photosensitivity
- teeth discoloration
What are the ADR’s for macrolides?
- GI
- hepatotoxicity
- arrhythmia
What are the ADR’s we should be aware of with clindamycin?
- GI disturbances
- pseudomembranous colitis
- skin rashes
What are the ADR’s foc linezolid?
- Myelosuppression
- headache
- rash
Community acquired pneumonia (CAP), is the 8th leading cause of death in the US, and manifests severely in the very young, elderly and chronically ill. What is the goal of treatement?
eradicate the organism, resolve clinical disease.
The Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) provides the guidelines for management of community acquired pneumonia, which apply to most patients.
What are some examples of patients that are excluded from these guidelines? Name up to 7
- ▫Immunocompromised patients
- ▫Solid organ, bone marrow, or stem cell transplant
- ▫Those receiving chemotherapy
- ▫Long-term high dose corticosteroids (> 30 days)
- ▫Congenital or acquired immunodeficiency
- ▫HIV with CD4 count < 350 cells/mm3
- ▫Children ≤ 18 years
CAP severity can be assessed with the CURB-65 score. What are the components of the CURB=65 score?
▫Confusion
▫Uremia (BUN > 19 mg/dL)
▫Respiratory rate (≥ 30 breaths/min)
▫Low blood pressure
SBP < 90 mmHg, DBP ≤ 60 mmHg
▫Age (≥ 65 Years)
What do the varios CURB-65 scores mean for patient disposition?
0-1: treat as outpatient
2: admit to hospital
3 or more: admit to ICU
What is another Pneumonia severity index?
Pneumonia severity index (PSI)
You can use CURB-65 plus minor criteria to determine need for ICU admission. What are the minor criteria?
▫Multilobar infiltrates
▫WBC < 4000 cells/mm3
▫PLT < 100,000 cells/mm3
▫Core temperature < 36 ˚C
▫Hypotension requiring aggressive fluid resuscitation
What are two absolute indications for ICU admission?
▫Mechanical ventilation
▫Septic shock (+ vasopressors)
Symptoms of CAP include cough, fever, sputum production and pleuritic chest pain. What should you do to make the diagnosis?
chest x-ray - if negative initiate antibiotics and repeat imaging in 1-2 days
Culture - To identify organism and sensitivities/resistances
Know the gram positive and negative organisms common to lung infections.
I recommend drawing out the flow chart for this one.
What type of organisms are not detectible on gram stain?
Atypical ones.
What are three infectious organisms associated with underlying bronchopulmonary disease?
▫H. influenzae
▫Moraxella catarrhalis
▫+ S. aureus during an influenza outbreak
What are two examples of infectious organisms associated wtih Chronic oral steroids or severe underlying bronchopulmonary disease, alcoholism, frequent antibiotic use?
▫Enterobacteriaceae
▫Pseudomonas aeruginosa
What type of infectious organisms should you be on the lookout for in classic aspiration pleuropulmonary syndrome in alcohol/drug overdose or in seizures with gingival disease or esophageal motility disorders?
Anaerobes - normal oral flora
What are the CAP recommendations for empiric treatment of outpatients who were previously healthy?
Macrolide PO (azithromycin, clarithromycin)
-OR-
Doxycycline PO
What are the CAP recommendations for empiric treatment of DRSP risk patients?
(Those with comorbidities, over 65 y/o, or used antimicrobials in past three months)
Respiratory fluoroquinolone PO (levofloxacin, moxifloxacin)
-OR-
B-lactam PO [high dose amoxicillin or amoxicillin-clavulanate preferred (alternates: ceftriaxone, cefuroxime)] PLUS a macrolide PO
What are the CAP recommendations for empiric treatment of Inpatient, non-ICU patients?
Respiratory FQ IV or PO (levofloxacin, moxifloxacin)
-OR-
B-lactam IV (ceftriaxone, cefotaxime, or ampicillin preferred) PLUS macrolide IV (azithromycin)
What are the CAP recommendations for empiric treatment in the inpatient, ICU setting?
B-lactam IV (ceftriaxone, cefotaxime, or ampicillin/sulbactam preferred) PLUS azithromycin IV
-OR-
B-lactam IV (ceftriaxone, cefotaxime, or ampicillin/sulbactam preferred) PLUS a respiratory FQ (levofloxacin, moxifloxacin)
What is the CAP modifying criteria for empiric treatment regimen when there is a risk of P. aeruginosa?
▫Structural lung disease (bronchiectasis)
▫Repeated COPD exacerbations
Frequent corticosteroid and/or antibiotic use
▫Prior antibiotic therapy
If there is a risk of P, aeruginosa, what are three recommended empiric regimens?
Antipseudomonal B-lactam IV (piperacillin-tazobactam, cefepime, imipenem, meropenem) PLUS either ciprofloxacin or levofloxacin
-OR-
Antipseudomonal B-lactam PLUS aminoglycoside (gentamicin) AND azithromycin
-OR-
Antipseudomonal B-lactam PLUS aminoglycoside AND antipneumococcal FQ
What are four modifying criteria for patients at risk for CA-MRSA?
▫End-stage renal disease (dialysis)
▫Injection drug abuse
▫Prior influenza
▫Prior antibiotic use (especially FQ)
What is the modified empiric regimen for CAP with risk of MRSA?
▫Add vancomycin IV or linezolid
▫Panton-Valentine leucocidin necrotizing pneumonia: add clindamycin or use linezolid
What are the criteria for transitioning a patient from IV to oral therapy?
4
- Hemodynamically stable
- Improving clinically
- Tolerating oral medications
- normal functioning GI tract
When considering transitioning patients from IV to oral therapy, “improving clinically” is listed as an indication. What are some specific criteria and the relevant baselines?
Up to 7
- Temperature ≤ 37.8 ˚C
- HR ≤ 100 bpm
- RR ≤ 24 breaths/min
- SBP ≥ 90 mmHg
- Arterial 02 saturation ≥ 90%
- Ability to maintain oral intake
- Normal mental status
What are the three guidlines that define the duration of the therapy?
For what situation is there an exception?
- Minimum 5 days treatment (usually 7-10 days)
- Must be afebrile for 48-72 hours
- No more than 1 CAP associated sign of clinical instability
Exception: psuedomonas = 15 day course of tx
What do HCAP, HAP and VAP stand for?
Healthcare-Associated (HCAP),
Hospital-Acquired (HAP),
Ventilator-Associated Pneumonia (VAP)
What does HCAP include?
•history of hospitalization or exposure to healthcare settings
When does HAP occur?
48 or more hours after admission
When does VAP occur?
48-72 hours after endotracheal intubation
Pseudomonas aeruginosa has demonstrated increasing resistance to:
- Piperacillin
- Ceftazidime
- Cefepime
- Imipenem
- Meropenem
- Aminoglycosides
- Fluoroquinolones
What are the two primary mechanisms this organisms uses to defeat our weapons?
- Multiple efflux pumps
- Decreased expression of outer membrane porin channel
Describe the resistance characteristics of klebsiella.
▫Klebsiella intrinsically resistant to ampicillin and can acquire resistance to cephalosporins and aztreonam –> ESBL production
Describe the resistance profile of enterobacter.
▫Enterobacter high frequency resistance development to cephalosporins during treatment
DRSP has an altered PBP (penicillin binding protein) that confers resistance. What are all US strains currently susceptible to?
Vancomycin and Linezolid
Early onset pathogens involved in HCAP, HAP and VAP include:
- ▫S. pneumoniae
- ▫H. influenzae
- ▫MSSA
- ▫Sensitive gram-negative: E. coli, K. pneumoniae, Enterobacter spp., Proteus spp., Serratia marcescens
What are the treatment protocols for this scenario? 4 options
- ▫Ceftriaxone OR
- ▫FQ (levofloxacin, moxifloxacin, ciprofloxacin) OR
- ▫Ampicillin/sulbactam OR
- ▫Ertapenem
Late onset HCAP, HAP and VAP organisms include:
- ▫P. aeruginosa
- ▫K. pneumoniae (ESBL+)
- ▫Acinetobacter
- ▫MRSA
What are the treatment options for this scenario?
▫Antipseudomonal cephalosporin (cefepime, ceftazidime) OR antipseudomonal carbapenem (imipenem, meropenem) OR B-lactam/B-lactamase inhibitor (piperacillin-tazobactam)
PLUS
▫Antipseudomonal FQ (ciprofloxacin, levofloxacin) OR aminoglycoside (gentamicin, tobramycin)
PLUS
▫Linezolid OR vancomycin
DOC for Strep Pneumo?
▫Non-resistant
- Penicillin G
- Amoxicillin
▫Resistant: Chosen on basis of susceptibility:
- Cefotaxime
- ceftriaxone
- levofloxacin
- moxifloxacin,
- vancomycin,
- linezolid
DOC for H. Influenza?
▫Non-B-lactamase producing
Amoxicillin
▫B-lactamase producing
2nd or 3rd generation cephalosporin, amoxicillin/clavulanate
DOC for Mycoplasma pneumoniae?
Macrolide
Tetracycline
DOC for C. pneumoniae?
Macrolide
Tetracycline
DOC for C. psittaci?
Doxycycline
DOC for Legionella?
- ▫Fluoroquinolone,
- azithromycin,
- doxycycline
DOC for enterobacteriaceae?
•Enterobacteriaceae (Klebsiella, E. coli, Proteus)
▫3rd or 4th generation cephalosporin, carbapenem (if ESBL producer)
DOC for P. aerugenosa?
▫Antipseudomonal B-lactam PLUS ciprofloxacin, levofloxacin, or an aminoglycoside
DOC for anaerobes such as bacteroides, fusobacterium, peptostreptococcus?
▫B-lactam/B-lactamase inhibitor, clindamycin
What is the DOC for staphylococcus aureus?
▫Methicillin-sensitive
Antistaphylococcal penicillin (nafcillin, oxacillin, dicloxacillin)
▫Methicillin-resistant
Vancomycin or linezolid
What is the drug of choice for influenza virus?
▫Oseltamivir, zanamivir
DOC for P. Jirovecii?
▫Trimethoprim/sulfamethoxazole
DOC for Bordatella pertussis?
▫Azithromycin, clarithromycin
DOC for coccidioides?
▫No treatment necessary if normal host
Itraconazole, fluconazole
DOC for histoplasmosis and blastomycosis?
Itraconazole
What are the neurominidase inhibitors?
•Oseltamivir (PO), zanamivir (INH)
What is the MOA of •Oseltamivir (PO), and zanamivir (INH)?
•analogs of sialic acid, interferes with release of progeny influenza virus from infected host cell
What adaptation can confer resistance to neurominidase inhibitors?
▫Point mutation in viral hemagglutinin (HA) or neuraminidase (NA) surface proteins
What are the M2 channel blockers we covered?
2
•Amantadine (PO), rimantadine (PO)
MOA for amantadine and rimantadine?
Block M2 proton ion channels of virus, inhibiting uncoating of viral RNA within host cell.
What is the only use for M2 channel blockers?
Influenza A only
What are six ADR’s of M2 channel blockers?
- ▫GI (nausea, anorexia)
- ▫CNS (nervousness, insomnia, light-headedness)
- ▫Severe behavioral changes
- ▫Delirium
- ▫Agitation
- ▫Seizures
What is the MOA for acyclovir?
three phosphorylation steps for activation, first step via virus specific thymidine kinase. Inhibits DNA synthesis.
Competes with deoxyGTP
What is the mechanism of the azole antifungals?
•inhibits fungal cytochrome P450, reducing production of ergosterol (component of fungi cell membrane)
What are the three azole antifungals we discussed?
Fluconazole
Itraconazole
Voriconazole
ADR’s of voriconazole?
Visual changes
photosensitivity
What is the MOA of Amphotericin B?
•binds ergosterol, changes permeability of cell, forms pores in membrane
What are the ADR’s for Amphotericin B?
•infusion related (fever, chills, vomiting, headache), cumulative toxicity (renal damage)
What are the three echinocandins?
- caspofungin
- micafungin
- anidulafungin
What is the MOA of echinocandins?
•inhibits synthesis of B(1-3)-glucan, disrupts fungal cell wall, and causes cell death