Opportunistic Infections Dr. Cluck EXAM 4 Flashcards
Which organism most commonly causes opportunistic infections?
-Pneumocystis jiroveci (PCP or PJP)
others:
-Toxoplasma gondii encephalitis
-Mycobacterium avium complex (MAC)
-Cytomegalovirus
-Cryptococcal meningitis
-Cryptosporidium
-Microsporidium
-Progressive Multifocal Leukoencephalopathy
At what CD4 count is prophylaxis recommended?
Which organism should be considered with specific CD4 counts?
<200: PJP
<100: Toxoplasma gondii
<50: all organism: Mycobacterium (MAC), CMV, Cryptococcal meningitis
What is the difference between primary and secondary prophylaxis?
What does it mean to treat an OI?
Primary: the patient does not have an opportunistic infection and is receiving a drug to prevent it
Secondary: the patient had the OI and is still at risk for the OI -> prophylaxis to prevent recurrence of the opportunistic infection (2nd infection)
Treatment: the patient has an active OI and is treated for it
What is the drug of choice for PCP prophylaxis?
Bactrim once daily
How does a patient with PCP present?
-dyspnea, fever, non-productive cough
-chest discomfort (getting worse within days to weeks)
-might have hypoxemia
-elevated LDH (pulmonary tissue damage)
What are alternative prophylactic options for PCP? other than Bactrium
-Dapsone
-Dapsone + pyrimethamine + leucovorin
-Atovaquone
-Aerosolized Pentamidine
the efficacy is lower compared to Bactrim
What is the drug of choice for PCP infection treatment?
What is the dose? -> EXAMSOFT
Bactrim
15-20 mg/kg per day
(5 mg/kg TID)
Which drugs can be used for PCP treatment if Bactrim is not tolerated?
EXAMSOFT
-Clindamycin + primaquine
test for G6PD for primaquine
-Steroids (must be within 72 hours)
Which drug can be used for Toxoplasmosis prophylaxis?
When are patients with HIV at risk for an infection?
EXAMSOFT
Bactrim
-CD4 < 100
What is the most common site for the reactivation of Toxoplasmosis gondii?
CNS
In order to develop the disease patients need to be exposed to the organism and develop IgG antibodies
Which drugs are used for Toxoplasmosis gondii treatment?
Pyrimethamine + sulfadiazine + leucovorin
2nd line:
-clindamycin + pyrimethamine (higher rate of relapse)
-TMP-SMX
treatment duration is 6 weeks (PCP is 3 weeks)
When would you start prophylaxis treatment for MAC and when not?
EXAM Question
start: if their CD4 count is <50 but they refuse antiretroviral therapy
Prophylaxis: azithromycin 1200 mg/wk + Bactrim !!!
don’t start: if they will get retroviral treatment and MAC is ruled out
Which drugs are used to treat a MAC infection?
clarithromycin + ethambutol +/- rifabutin
other agents:
-FQ
-Azithromycin
-Amikacin/streptomycin
Which drugs are used to treat CMV?
-Acyclovir (poor substrate of UL97)
-Ganciclovir (IV)
-valganciclovir (oral)
activated by UL 97 (produced by the virus)
cidofovir and foscarnet are reserved for resistance or poor resistance (do not require bioactivation)
Which drugs are used for the treatment of Cryptococcus meningitis?
Therapy: Induction -> Consolidation -> maintenance
amphotericin B with flucytosine (to sterilize the CSF) followed by fluconazole for 8 week
What is Immune reconstitution inflammatory syndrome (IRIS)?
the immune system recovers after antiretroviral therapy and reacts with an acute inflammatory response to a pre-existing infection (was there before but the immune system didn’t react to it)
How are symptoms of IRIS managed?
Corticosteroids
How are opportunistic infections treated that don’t have a definitive therapy?
Antiretroviral therapy (strengthens the immune system by treating the virus that make them immunocompromised)
examples:
Cryptosporidium
Microsporidium
PML (causative pathogen is JC virus)
