Opportunistic Infections Flashcards
What are opportunistic infections?
infections more frequent or more severe because of HIV mediated immunosuppression
HIV gets in cells –> destruction –> decreased CD4 –> immunosuppressed
What are normal CD4 counts in adults?
800-1200 cells/mm^3
What CD4 counts are associated with the development of OIs?
counts <500 cells/mm^3 and especially <200 cells/mm^3
What infection can occur at any CD4 cell count?
mycobacterium TB, pneumonias, and dermatomal varicella zoster
What infections occur at CD4 count < 500 cells/mm^3?
candidiasis and leukoplakia
What infections occur at CD4 count < 200 cells/mm^3?
PJP, CMV retinitis, toxoplasmosis, MAC, crytoococcus meningitis or diarrhea, lymphomas, and Kaposi’s sarcoma
What can increase HIV viral load?
tuberculosis and syphilis can increase HIV viral load, increasing the risk of viral transmission and progression
What is primary prophylaxis for OIs?
administration of an anti-infective agent to prevent the 1st epidose of a particular OI in a pt living with HIV when they are at risk for developing that OI based on their CD4 count
What is secondary prophylaxis for OIs?
chronic maintenance or chronic suppressive therapy: administration of an anti-infective therapy to prevent further recurrences of a particular OI in a pt living with HIV after they have been successfully treated for that OI and remain at risk for developing that OI based on their CD4 cell count
When to initiate ART DURING an acute OI?
when effective therapy is not available: progressive mutifocal leukoencephalopathy (PML), cryptosporidiosis, and Kaposi’s sarcoma
improvement in immune function from ART will help with the resolution of these OIs
When to NOT immediately start ART in the setting of an acute OI?
potential development of the immune reconstitution inflammatory syndrome (IRIS)
overlapping or additive drug toxicities
drug interactions between ART and OI therapy
What is immune reconstitution inflammatory syndrome (IRIS)?
characterized by fever, inflammation, and worsening clinical manifestations of the OI
can be seen during the actue treatment of MAC, TB, PJP, toxoplasmosis, Hep B & C, CMV, cryptococcus, histoplasmosis, and varicella zoster infections
Who is IRIS more likely to occur in?
patients with low CD4 cell counts (<50 cells/mm^3) and high HIV RNA levels (>100,000 copies/mL)
occurs within first 4-8 hours of ART
How long to wait for a clinical response to OI therapy before starting ART if IRIS present?
wait 2 weeks before initiating ART
exception: start ART within 2 weeks of starting TB treatment if CD4 count <50 cells/mm^3 or within 8 weeks if CD4 count is higher
What is the treatment for IRIS?
treat the OI
mild: use NSAIDs for fever and pain; inhaled corticosteroids for broncospasms
severe: prednisone 1-2 mg/kg for 1-2wks
Who to avoid steroids in?
cryptococcal meningitis or Kaposi’s sarcoma due to worse outcomes
What are the most common OIs observed in patients with HIV infection?
oropharyngeal candidiasis (thrush) and esophageal candidiasis
majority of these infections caused by candida albicans
Infections with candida species are most common when CD4 is what?
CD4 cell count is < 200 cells/mm^3
esophageal candidiasis typically occurs at lower CD4 counts
What are the infections due to candida species?
oropharyngeal candidiasis, esophageal candidiasis, and vulvovaginal candidiasis
What is the diagnosis of oropharyngeal candidiasis?
clinical exam -
painless, creamy white plaque-like lesions on buccal mucosa, hard or soft palate, oropharyngeal mucosa or tongue surface; dry mouth and taste alterations
What is the preferred treatment for oropharyngeal candidiasis?
preferred: fluconazole 200 mg loading dose, followed by 100-200 mg PO daily for 7-14 days
as effective/superior to topical therapy
What are SEs of oral azoles?
N/V/D, abdominal pain, increased LFTs
monitor LFTs and QTc if treatment > 21 days
What is alternative treatment for oropharyngeal candidiasis?
topical agents for initial, mild-moderate episodes only
advantages: reduces systemic drug exposure, diminishes risk of drug-drug interactions and SEs, and decreases risk of resistance
disadvantages: use impacted by bad taste, GI SEs, and multiple daily dosing
What are the topical agents used in the treatment of oropharyngeal candidiasis?
nystatin suspension (100,000 units/mL): 5 mL swish and swallow QID x 7-14 days - should be thoroughly rinsed in mouth and retained in mouth for as long as possible before swallowing
clotrimazole troches (10 mg lozenge): 10 mg oral lozenge 5 times daily for 7-14 days - should be dissolved slowly in the mouth over 15-30 min
