Antiinfectives Chapter 13

Question 1

What are the clinical indications for giving aerosolized Pentamidine?

Answer 1

Prevention of PCP pneumonia in HIV+ patients w/ history of PCP infections or a CD4 count of 200/mm or less

Question 2

What are the clinical indications for giving aerosolized Ribavirin?

Answer 2

Treatment of hospitalized infants with severe lower respiratory tract infection caused by RSV

Question 3

What are the clinical indications for giving aerosolized Tobramycin

Answer 3

Management of chronic pseudomonas aeruginosa infection in CF

Question 4

What are the clinical indications for giving inhaled zanamivir

Answer 4

treatment of influenza virus in adults and children over 5 who have been symptomatic for no more than 2 days

Question 5

What is the trade name for Pentamadine ?

Answer 5

NebuPent

Question 6

What is the dosage, mode of delivery, and frequency for Pentamidine?

Answer 6

300 mg powder in 6 mL sterile water; once per month (for PCP prophylaxis); nebulized

• Given with Respiguard
• Must be given with a series of one way valves and an expiratory filter
• Must take care NOT to expose it to environment
• Can give in negative pressure booth or room

Question 7

What is the dosage, mode of delivery and frequency for Ribavirin?

Answer 7

6 g powder in 300 mL sterile water via SPAG nebulizer via mask (treatment lasts 12-18 hours/day for 3-7 days

Question 8

What is the trade name for Ribavirin?

Answer 8

Virazole

Question 9

How should you mix Ribavirin and Pentamadine?

Answer 9

You shouldn’t! It is not within RRT scope of practice. Should be mixed by the pharmacy and delivered by hand as it will foam if shaken

Question 10

What is the dosage, mode of delivery and frequency for Tobi?

Answer 10

300 mg/5mL ampule
28 days on, 28 days off
to treat/prevent pseudomonas aeruginosa in CF

Question 11

General indications for inhaled anti-infectives are:

Answer 11

1 used as adjunct to systemic therapy

2. topical deposition of agents inappropriate for systemic administration (such as Nystatin)
3. topical deposition with pulmonary infection where perfusion is limited and systemic therapy has failed (aspergilliosis)
4. for topical deposition of agent that is more effective by this route (such as pentamidine)
5. to eliminate an organism that is colonizing the respiratory tract (infected sputum in CF or bronchiectasis)
6. to reduce the severity of systemic side effects

Question 12

What are the limitations/disadvantages of aerosolized anti-infective agents

Answer 12

1. Therapy is patient dependent
   2 Bronchospasm
2. systemic side effects may occur
3. drugs may be inactivated by sputum proteins
4. drug may not be deposited in desired site
5. dosages are not guaranteed
6. optimal delivery and equipment techniques have not been determined

Question 13

Approximately what percentage of aerosolized anti-infective agents reach the bloodstream?

Answer 13

less than 10%

Question 14

Pentamidine is a(n) ___ agent
A antifungal
B antibacterial
C anti-protozoa

Answer 14

C anti-protozoal-

prevents overgrowth of normal flora

Question 15

What happens (pharmodynamically) when Pentamidine is given IV or IM?

Answer 15

it goes to the liver, kidneys and pancreas and binds to tissues

Question 16

How long does it take for Pentamidine to clear the body tissues?

Answer 16

can be seen in urine 270 days after it is given

Question 17

What is the rationale for giving Pentamidine via aerosol instead of IV/IM?

Answer 17

local targeted delivery provides fewer and less severe side effects compared with systemic administration

Question 18

Why does p carinii disproportionally effect some patient populations?

Answer 18

all mammals are infected w/ p carinii at an early age but those who are immunocompromised get PCP pneumonia more easily

Question 19

What is the best MMD to deliver aerosolized Pentamadine?

Answer 19

1 to 2 microns

Question 20

What is the mode of action of Pentamadine?

Answer 20

The exact mode of action is not known BUT IT DOES block RNA and DNA synthesis, inhibits oxidative phosphorylation and interferes with folate transmormation

Question 21

How is Pentamadine excreted by the body?

Answer 21

75% in the urine

25% in the feces

Question 22

What are the side effects of aerosolized Pentamadine?

Answer 22

• cough and bronchial irritation
• shortness of breath
• bad (bitter) taste
• spontaneous pneumothorax
• rash, conjunctivitis
• pancreatitis, renal insufficiency, digital necrosis in the feet, hypoglycemia/diabetes

Question 23

Why do we use ultra small particle size to deliver Pentamadine?

Answer 23

to reduce airway impaction and increase alveolar deposition

Question 24

Tobramycin is a(n) ___________(class of drug) used to __________ in CF patients

Answer 24

antibiotic; treat or prevent pulmonary infections caused by p. aeruginosa

Question 25

What specific type of nebulizer is used to deliver Tobramycin?

Answer 25

PARI LC Plus

Question 26

What is the mode of action of Tobi?

Answer 26

binds to subunit of bacterial ribosomes and blocks protein synthesis in the bacteria and causes cellular death

Question 27

What are the side effects of aerozolized Tobi?

Answer 27

They differ for oral and nebulized.
Oral: ototoxicity, nephrotoxicity, neuromuscular blockade, decreased magnesium levels, fetal harm
Nebulized: tinnitus (ringing ears), voice alterations