Influenza, sinusitis, and group A streptococcal pharyngitis

Question 1

Symptoms of flu

Answer 1

Abrupt onset of fever, headache, myalgia, and malaise

Symptoms generally resolve in 3-7 days

Transmission and shedding:
_ During incubation period, 1st 24-48hrs
_ Close contact: Sneezing and coughing

Cold vs Flu in table in ppt

Question 2

Two major surface glycoprotein antigens

Answer 2

Principal antigen, hemagglutinin (HA or H)
responsible for cell attachment

Enzymatically active neuraminidase (NA or N)
assists virus maturation and release

Question 3

Influenza

Answer 3

Three main types
Type A (major outbreaks and severe disease) and Type B

Type C (sporadic upper respiratory infections)

Usually more severe than common cold

Serious illness and death are highest in at risk populations: elderly, Children < 2 years, those with chronic conditions

Question 4

M2 inhibitor drugs

Answer 4

Amantidine, rimantidine

Question 5

M2 inhibitor MOA

Answer 5

Prevent viral replication by blocking M2 protein ion channel - prevents uncoating of virus

“M2 channel blockers”- inexpensive, long history of use.

Blocks M2 channel in viral membrane once it has entered the host cell. (Influenza B has NB channels)

M2 Channel allows H+ to enter. Acid required for viral uncoating.

Inhibits uncoating of virus once inside host cells.

Not dependent on replication– Only inhibits ability to spread.

Question 6

Side effect of M2 inhibitor

Answer 6

CNS toxicity (reversible)
Insomnia, dizziness, nervousness, difficulty concentrating
Rimantidine less CNS ADRs

Question 7

What’s special about Amantadine?

Answer 7

Amantadine also has anti-tremor properties: Weakly increase dopamine in brain. Also used for Parkinson-like or drug-induced tremors, etc.

Question 8

Neuraminidase Inhibitors (NAIS) drugs

Answer 8

Zanamivir
Oseltamivir
Peramivir

Question 9

NAIS MOA

Answer 9

FDA indications: Prophylaxis and Tx of influenza A & B.

MOA: Prevent the release of new virions from the cell surface
Binds the surface antigen neuraminidase, on influenza A & B viruses preventing release of new viruses.

Neuraminidase releases virus from cell surface

Question 10

Peramivir

Answer 10

Rapivab

Single IV dose - strong, prolonged affinity
Renal adjust CrCl <50 (90% unchanged in urine)

SEs:
diarrhea
reports of delirium/ abnormal behavior
primarily children, abrupt onset, rapid resolution

Question 11

Zanamivir

Answer 11

Relenza

Administered via oral inhalation with Diskhaler
2 inhalations (10 mg) BID x 5 days

Begin within 48 hrs of symptom onset

Adverse Reaction = Bronchospasm

Advantages:
Less resistance seen than with oseltamivir

Disadvantages:
Administration may be difficult (5-6 steps per dose)

Question 12

Oseltamivir

Answer 12

Tamiflu

Oral prodrug neuraminidase inhibitor
75 mg po BID x 5 days

Renally adjusted, no use in hemodialysis
Begin within 48 hrs of symptom onset
Adverse Reaction = Nausea/Vomiting

Advantages:
Oral formulation, capsule or suspension

Disadvantages:
Cochrane Review and efficacy controversy
Publication bias

Question 13

Tamiflu is preferred for which population?

Answer 13

Elderly, children < 2 years, those with chronic conditions

The other population are not recommended

Question 14

Acute Rhinosinusitis and Viral Rhinosinusitis

Answer 14

Mostly caused by virus 97%

Cant be cured by ABx

Question 15

Acute Bacterial Rhinosinusitis (ABRS)

Answer 15

Acute rhinosinusitis that is caused by bacterial infection when:
_ Symptoms or signs of acute rhinosinusitis fail to improve within 10 days or more beyond the onset of upper respiratory symptoms
OR
_ Symptoms or signs of acute rhinosinusitis worsen within 10 days after an initial improvement (double worsening)

Question 16

Treatment for children’s ABRS

Answer 16

Kids ABRS = Amoxicillin-clavulanate 10-14 days

45 mg/kg amoxicillin component per day; 2-divided doses

Question 17

What criteria and treatment for resistance of Strep Pneumo for ABRS in children?

Answer 17

T >39C; Age <2yrs; daycare; Abx within 30d; Hospitalization within 5d

90 mg/kg amoxicillin component per day; 2-divided doses

Question 18

Signs of resistance of Strep Pneumo for children and adult

Answer 18

T >39C; Age <2yrs; daycare; Abx within 30d; Hospitalization within 5d

> 65yo; hospitalized in last 5days; Abx <30d, or immunocompromised

Question 19

What treatment for resistance of Strep Pneumo for ABRS in adults?

Answer 19

> 65yo; hospitalized in last 5days; Abx <30d, or immunocompromised

2 g (XR) po BID

Question 20

What option for PCN-allergy for ABRS?

Answer 20

Pcn-allergic: either doxycycline or fluoroquinolone (levofloxacin / moxifloxacin)

Question 21

Treatment for adult ABRS

Answer 21

Adults ABRS = Amoxicillin-clavulanate 5-7 days

500 mg/125 mg po TID or 875 mg/125 mg po BID

Question 22

Which ABx should not be used for ABRS for resistance issue?

Answer 22

azithromycin, clarithromycin, or tmp-smx

Question 23

Signs for viral pharyngitis or viral throat infection

Answer 23

cough
runny nose
hoarseness
mouth sores

Question 24

Signs for bacterial pharyngitis or bacterial throat infection

Answer 24

IF 3 or more of these symptoms (Centor criteria):
sudden onset pain
tonsillar exudates
fever
cough and significant rhinorrhea are usually absent

THEN confirm with RADT strep before ABx is prescribed

Mostly caused by group A streptococcal (GAS)

Question 25

Treatment for GAS pharyngitis for children

Answer 25

Children <27kg: PCN VK 250mg PO BID-TID x10d
OR
Children: Amoxicillin 25mg/kg PO BID x10d

Question 26

Treatment for GAS pharyngitis if PCN allergy

Answer 26

3rd gen cephalosporins (cefdinir); Clindamycin

Question 27

Treatment for GAS pharyngitis for adult

Answer 27

Adolescents/Adults: PCN VK 500mg PO TID x10d