Antiinfectives Chapter 13 Flashcards
What are the clinical indications for giving aerosolized Pentamidine?
Prevention of PCP pneumonia in HIV+ patients w/ history of PCP infections or a CD4 count of 200/mm or less
What are the clinical indications for giving aerosolized Ribavirin?
Treatment of hospitalized infants with severe lower respiratory tract infection caused by RSV
What are the clinical indications for giving aerosolized Tobramycin
Management of chronic pseudomonas aeruginosa infection in CF
What are the clinical indications for giving inhaled zanamivir
treatment of influenza virus in adults and children over 5 who have been symptomatic for no more than 2 days
What is the trade name for Pentamadine ?
NebuPent
What is the dosage, mode of delivery, and frequency for Pentamidine?
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
What is the dosage, mode of delivery and frequency for Ribavirin?
6 g powder in 300 mL sterile water via SPAG nebulizer via mask (treatment lasts 12-18 hours/day for 3-7 days
What is the trade name for Ribavirin?
Virazole
How should you mix Ribavirin and Pentamadine?
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
What is the dosage, mode of delivery and frequency for Tobi?
300 mg/5mL ampule
28 days on, 28 days off
to treat/prevent pseudomonas aeruginosa in CF
General indications for inhaled anti-infectives are:
1 used as adjunct to systemic therapy
- topical deposition of agents inappropriate for systemic administration (such as Nystatin)
- topical deposition with pulmonary infection where perfusion is limited and systemic therapy has failed (aspergilliosis)
- for topical deposition of agent that is more effective by this route (such as pentamidine)
- to eliminate an organism that is colonizing the respiratory tract (infected sputum in CF or bronchiectasis)
- to reduce the severity of systemic side effects
What are the limitations/disadvantages of aerosolized anti-infective agents
- Therapy is patient dependent
2 Bronchospasm - systemic side effects may occur
- drugs may be inactivated by sputum proteins
- drug may not be deposited in desired site
- dosages are not guaranteed
- optimal delivery and equipment techniques have not been determined
Approximately what percentage of aerosolized anti-infective agents reach the bloodstream?
less than 10%
Pentamidine is a(n) ___ agent
A antifungal
B antibacterial
C anti-protozoa
C anti-protozoal-
prevents overgrowth of normal flora
What happens (pharmodynamically) when Pentamidine is given IV or IM?
it goes to the liver, kidneys and pancreas and binds to tissues
How long does it take for Pentamidine to clear the body tissues?
can be seen in urine 270 days after it is given
What is the rationale for giving Pentamidine via aerosol instead of IV/IM?
local targeted delivery provides fewer and less severe side effects compared with systemic administration
Why does p carinii disproportionally effect some patient populations?
all mammals are infected w/ p carinii at an early age but those who are immunocompromised get PCP pneumonia more easily
What is the best MMD to deliver aerosolized Pentamadine?
1 to 2 microns
What is the mode of action of Pentamadine?
The exact mode of action is not known BUT IT DOES block RNA and DNA synthesis, inhibits oxidative phosphorylation and interferes with folate transmormation
How is Pentamadine excreted by the body?
75% in the urine
25% in the feces
What are the side effects of aerosolized Pentamadine?
- cough and bronchial irritation
- shortness of breath
- bad (bitter) taste
- spontaneous pneumothorax
- rash, conjunctivitis
- pancreatitis, renal insufficiency, digital necrosis in the feet, hypoglycemia/diabetes
Why do we use ultra small particle size to deliver Pentamadine?
to reduce airway impaction and increase alveolar deposition
Tobramycin is a(n) ___________(class of drug) used to __________ in CF patients
antibiotic; treat or prevent pulmonary infections caused by p. aeruginosa
What specific type of nebulizer is used to deliver Tobramycin?
PARI LC Plus
What is the mode of action of Tobi?
binds to subunit of bacterial ribosomes and blocks protein synthesis in the bacteria and causes cellular death
What are the side effects of aerozolized Tobi?
They differ for oral and nebulized.
Oral: ototoxicity, nephrotoxicity, neuromuscular blockade, decreased magnesium levels, fetal harm
Nebulized: tinnitus (ringing ears), voice alterations
