Lecture 2: Pharm of Anti-influenza

Question 1

What are the 3 neuraminidase inhibitors used as anti-influenza drugs and which can be given orally, via IV, and inhalation?

Answer 1

• Oseltamivir = oral
• Zanamivir = inhaled
• Peramivir = IV

Question 2

What are the 2 adamantanes used as anti-influenza drugs?

Answer 2

• Amantadine
• Rimantadine

Question 3

Which anti-influenza class has activity against both influenza A and B?

Answer 3

Neuraminidase inhibitors

Question 4

What is the MOA of the neuraminidase inhibitors as anti-influenza drugs?

Answer 4

Interfere w/ release of progeny influenza A and B from infected host cells, thus stopping spread of infection

Question 5

Which rare/unique AE associated with neuraminidase inhibitors has been more frequently seen in adolescents and adults living in Japan?

Answer 5

Neuropsychiatric events (self-injury or delirium)

Question 6

3 common AE’s of Olseltamivir; what may be done to decrease them?

Answer 6

• HA, nausea, and vomiting
• Take w/ food to decrease N/V

Question 7

Doses of Oseltamivir need to be adjusted in pt’s with what underlying problem?

Answer 7

Renal insufficiency

Question 8

Which anti-influenza class of drugs can be given as once-daily prophylaxis?

Answer 8

Neuraminidase inhibitors (oseltamivir and/or zanamivir)

Question 9

What are the 2 common AE’s of oseltamivir associated with prophylactic use?

Answer 9

Fatigue and diarrhea

Question 10

After inhalation of Zanamivir, where does 80-90% of it deposit?

Answer 10

Oropharynx

Question 11

Major AE’s associated with Zanamivir; should not be administered with what underlying issue?

Answer 11

• Cough
• Bronchospam (ocassionally severe)*** –> don’t give to pt w/ underlying airway disease!
• Reversible ↓ in pulmonary function

Question 12

When should tx with neuraminidase inhibitors be given to be most effective against influenza?

Answer 12

Within 48 hours

Question 13

What is the main potential AE of peramivir, and which rare AE has been seen?

Answer 13

• Main = diarrhea
• Hypersensitivity rxns –> Steven-Johnsons syndrome, Erythema multiforme have rarely been seen
• ↑ risk for delirium, hallucinations, and abnormal behavior

Question 14

What is the MOA of the Adamantanes, Amantadine and Rimantadine used as anti-influenza drugs?

Answer 14

Block M2 proton ion channel –> inhibit uncoating of the viral RNA WITHIN infected cells, thus preventing its replication

Question 15

Both Adamantanes require dose reductions in the elderly and pt’s with renal insufficiency, but which must be reduced in hepatic insufficiency as well?

Answer 15

Rimantadine

Question 16

Which Adamantane is excreted unchanged in the urine and which undergoes extensive metabolism?

Answer 16

• Amantadine is excreted unchanged
• Rimantadine undergoes extensive metbolism

Question 17

Why are the Adamantanes no longer recommended for prevention or treatment of influenza?

Answer 17

High rates of resistance in both H1N1 and H3N2 viruses

Question 18

Which anti-influenza class are both teratogenic and embryotoxic?

Answer 18

Adamantanes

Question 19

2 most common AE’s of the Adamantanes?

Answer 19

• GI (nausea and anorexia)
• CNS –> nervousness, difficulty in concentrating, insomnia, light-headedness

Question 20

What is a more serious AE associated with the Adamantanes; more frequent with which drug in the class?

Answer 20

• Marked behavioral changes + Delirium + Hallucinations
• Agitation + Seizures
• More frequent w/ amantadine