Allergy, Flu, Pneumonia Flashcards
What do you use antihistamines for?
Immediate type hypersensitivity reactions
What two kinds of activity to antihistamines have?
Anticholinergic
Antimuscarinic
What kind of drugs are antihistamines?
Reversible competitive H1 receptor antagonists
What is the affect of antihistamines?
Reduce or prevent physiologic effects of histamine release
Do antihistamines affect the pre-released histamine?
No
What is an issue with first-generation antihistamines?
They produce sedation
What is an advantage of second generation antihistamines and what is the result?
They are peripherally selective drugs
They are much less sedating
What is a ethanolamine antihistamine?
Diphenhydramine (benadryl)
What is a phenothiazine antihistamine?
Promethazine
What are some classes of first generation antihistamines?
Ethanolamines
Phenothiazines
Piperazines
What is a piperazine antihistamine?
Hydroxyzine
What are some classes of second generation antihistamines?
Phthalazinone
Piperazine
Piperidines
What is a phthalazinone antihistamine?
Azelastine
What is a piperazine antihistamine? What is it a metabolite of?
Cetirizine
Active metabolite of hydroxyzine
What are piperidine antihistamines?
Loratadine
Desloratadine
Fexofenadine
What is desloratadine a metabolite of?
Active metabolite of loratadine
When is desloratadine contraindicated?
In pts hypersensitive to loratadine
When is cetirizine contraindicated?
In pts who are hypersensitive to hydroxyzine
Do 2nd degree antihistamines have more or less sedative properties?
Less
What activities should pts on antihistamines take caution with?
Driving
Tasks requiring alertness
What precautions should be taken with children taking antihistamines?
Supervise children in hazardous activities
What substances should you avoid with antihistamines?
Co-administration of other CNS depressants (drugs or alcohol)
AEs of promethazine
Possible fatal respiratory depression
Lower seizure threshold
Prolong QT interval
Can promethazine induced respiratory depression be reveresed with naloxone?
No
When is promethazine contraindicated?
Children < 2 years
What is a concern with IV/SQ administration of promethazine?
Tissue necrosis
What is key with influenza? What can we do to deal with this?
Prevention
Promote annual immunization
What is the MOA of amantadine?
Chemoprophylaxis of signs and sx of influenza A
What does amantadine treat?
Uncomplicated RTI with influenza a
What is the MOA of oseltamivir?
Chemoprophylaxis of signs and sx of influenza A/B
What does oseltamivir treat?
Uncomplicated RTI with influenza a/b
What might decrease the effectiveness of oseltamivir?
Emergence of resistance
When do you give oseltamivir as prophylaxis?
Following contact w/ an infected individual
When do you give oseltamivir as tx?
W/in 2 days of onset of flu sx
What do you give zanamivir for prophylactically?
The flu for pts >5 years for flu a/b
What do you treat with zanamivir?
Flu a/b in pts > 7 years old
What is rimantadine used for in adults?
Prophylaxis and tx of influenza A in adults
What is rimantadine used for in kids?
Prophylaxis of flu a in kids
When do you start rimantadine?
ASAP after sx appear
Preferably w/in 48 hours
How long do you give rimantadine?
7 days
What populations do you reduce rimantadine dosing for?
Elderly
Nursing home pts
Are community acquired pneumonia (CAP) organisms multi-drug resistant?
Generally not
What are some common CAP organisms?
Streptoccous pneumonia
Haemophilus influenzae
What is the pneumonia severity index?
PSI -> see slide 46
What is the CAP tx algorithm?
see slide 47
What are the CAP empiric antibiotics?
See slide 48
What organism is gram positive and has cocci in clusters?
S. aureus
What should you add for CAP tx if the stain comes back as S aureus?
Vancomycin
What organism causes CAP and is gram negative?
Pseudomonas
What should you add if the CAP organism is pseudomonas?
Anti-pseudomonal (ex: Tazo, cefepime)
What do many WBCs on gram stain indicate?
Pneumonia more likely
Is pneumonia more likely with more or less organisms on gram stain?
Many organisms
Is pneumonia more likely with mixed morphology or single?
Single morphology
Severe CAP empiric tx?
See slide 50
When do you classify pneumonia as hospital acquired (HAP)?
When it is new after 3-5 days as inpatient
Is HAP more or less likely to be multi-drug resistant?
More likely
What drug should you consider to add for HAP?
Vancomycin
What can you add for broader mutli-drug resistance coverage?
High dose Pip/Tazo (zosyn)
Cefepime
Imipenem/cilastatin
What dose of Pip/Tazo do you give for MDR? What’s something you have to take into consideration?
- 45 g q 6-8 hours
* renally adjust
What dose of cefepime do you give for MDR? Whats an exception?
1 g q 12 hours
2 g q 8 hours for febrile neutropenia
What dose of imipenem/cilastatin do you give for MDR?
0.5 - 1 g q 6-12 hours
How are long-term care facilities more like hospitals?
Chronically ill pts
Long lengths of stay
May have instrumentation in place
Increased likelihood of MDR colonization/infection
Do you treat health care associated pneumonia more like CAP or HAP?
HAP
What is aspiration pneumonitis?
Acute lung injury after inhalation of regurgitated gastric contents
Is aspiration pneumonitis usually witnessed or not?
Witnessed
What happens with aspiration pneumonitis?
Chemical reaction due to stomach acidity
When does aspiration pneumonia develop?
After inhalation of colonized oropharyngeal organisms
How do you dx aspiration pneumonia?
CXR to see infiltrate in at risk pts
Is aspiration pneumonia witnessed or nah?
Not witnessed
What is aspiration pneumonia?
An infection in the lungs due to colonized bacteria
What are some RF for aspiration pneumonia?
Older
Antacids
PPIs
poor dentition
What are some protective factors against aspiration pneumonia?
Few organisms
Cough reflex
Active ciliary transport
Aspiration tx
See slide 57
