HIV/AIDs Flashcards
1
Q
What is the primary target cell of HIV?
A
CD4+ T-helper lymphocytes.
2
Q
Which HIV protein binds to CD4 receptors?
A
gp120.
3
Q
What are the three stages of HIV infection?
A
1) Acute retroviral syndrome, 2) Chronic HIV infection, 3) AIDS.
4
Q
What are symptoms of acute retroviral syndrome?
A
Flu-like illness: fever, sore throat, rash, myalgia, lymphadenopathy.
5
Q
What occurs during chronic HIV infection?
A
Asymptomatic phase with slow CD4 decline and viral set-point established.
6
Q
How is AIDS defined?
A
CD4 <200 cells/mm³ or AIDS-defining opportunistic infection.
7
Q
What are the three main routes of HIV transmission?
A
1) Sexual contact, 2) Blood exposure, 3) Perinatal transmission.
8
Q
Which sexual activity has the highest HIV transmission risk?
A
Receptive anal intercourse.
9
Q
Can HIV be transmitted via casual contact?
A
No, HIV is not spread by casual contact like hugging, sharing food, or kissing.
10
Q
What is the recommended initial HIV screening test?
A
4th generation HIV antigen/antibody immunoassay.
11
Q
What confirms a positive HIV screening test?
A
HIV-1/HIV-2 differentiation or NAT (nucleic acid test).
12
Q
What should you tell patients using the OraQuick home HIV test?
A
It’s a screening tool only. Positive results require confirmatory testing.
13
Q
How long is the window period for OraQuick?
A
Up to 3 months after exposure.
14
Q
What should you do if you test negative with OraQuick after recent exposure?
A
Retest after the window period and use prevention strategies.
15
Q
What are the two surrogate markers for HIV?
A
CD4 count and HIV RNA (viral load).
16
Q
What does CD4 count indicate?
A
Immunocompetence and risk of opportunistic infections.
17
Q
What does HIV viral load indicate?
A
Effectiveness of antiretroviral therapy and progression risk.
18
Q
What defines HIV infection?
A
Presence of HIV without meeting criteria for AIDS.
19
Q
What defines AIDS?
A
CD4 <200 or diagnosis of AIDS-defining condition.
20
Q
How do NRTIs work?
A
They inhibit reverse transcriptase by acting as chain terminators in viral DNA.
21
Q
How do NNRTIs work?
A
They bind to an allosteric site on reverse transcriptase, causing a conformational change.
22
Q
How do protease inhibitors (PIs) work?
A
They block viral protease, preventing maturation of new virions.
23
Q
How do INSTIs work?
A
They inhibit the integrase enzyme, preventing HIV DNA from integrating into the host genome.
24
Q
What does a CCR5 antagonist do?
A
Blocks CCR5 co-receptor to prevent viral entry.
25
What does an attachment inhibitor like fostemsavir do?
Blocks gp120 from binding to CD4 receptors.
26
What does a post-attachment inhibitor like ibalizumab do?
Binds CD4 after gp120 attaches, blocking further entry steps.
27
What does a capsid inhibitor like lenacapavir do?
Disrupts capsid formation and multiple stages of viral replication.
28
What is the standard adult dose of dolutegravir?
50 mg once daily.
29
When should dolutegravir be dosed twice daily?
If used with certain enzyme inducers like rifampin.
30
When should efavirenz be taken?
At bedtime on an empty stomach.
31
How should nevirapine be initiated?
Start with a 14-day lead-in to reduce rash risk.
32
When should etravirine be taken?
With food.
33
When should rilpivirine be taken?
With a meal of at least 390 calories. Avoid with PPIs.
34
How should atazanavir be taken?
With food. Avoid PPIs.
35
How is elvitegravir taken?
With food and must be boosted with cobicistat.
36
How is cabotegravir given?
Intramuscular injection after oral lead-in. Maintenance every 2 months.
37
How is ibalizumab administered?
IV infusion every 2 weeks.
38
How is lenacapavir administered?
Subcutaneous injection with a long half-life (8–12 weeks).
39
What are class effects of NRTIs?
Lactic acidosis and hepatic steatosis.
40
What are TDF-specific side effects?
Renal impairment and bone mineral loss.
41
What are ABC-specific risks?
Hypersensitivity and possibly increased MI risk.
42
What are NNRTI side effects?
Rash, hepatotoxicity, CNS effects (especially efavirenz).
43
What are PI side effects?
GI upset, lipodystrophy, insulin resistance.
44
What are INSTI side effects?
Weight gain.
45
What is a known cobicistat side effect?
Benign increase in serum creatinine.
46
How should INSTIs be spaced with antacids?
Separate by 6 hours.
47
What are preferred benzodiazepines with PIs?
Lorazepam, oxazepam, and temazepam.
48
What corticosteroid is preferred with PIs?
Beclomethasone.
49
Which statins are safer with PIs?
Low doses of atorvastatin, rosuvastatin, pravastatin, or pitavastatin.
50
How does dolutegravir affect metformin?
It increases metformin levels; metformin dose may need to be reduced.
51
How should PDE5 inhibitors be used with PIs?
Very low doses every 48–72 hours.
52
How should cation supplements be used with INSTIs?
Separate by 6 hours unless taken with food.
53
Which antiretroviral class typically requires renal dose adjustment?
NRTIs (except abacavir).
54
Which NRTI does not require renal adjustment?
Abacavir – it's cleared hepatically.
55
What test is required before starting abacavir?
HLA-B*5701 genetic test to avoid hypersensitivity.
56
What test is required before starting maraviroc?
Tropism assay to confirm CCR5-tropic virus.
57
Where can you find the federal HIV treatment guidelines?
https://clinicalinfo.hiv.gov
58
What are the goals of ART therapy?
1) Suppress HIV RNA, 2) Restore/preserve immune function, 3) Reduce morbidity, 4) Prevent transmission.
59
What is the general structure of an initial ART regimen?
2 NRTIs + 1 drug from INSTI, NNRTI, or boosted PI class.
60
When is ART recommended for people with HIV?
Immediately after diagnosis, regardless of CD4 count.
61
When should ART be delayed?
In cryptococcal or TB meningitis due to risk of IRIS.
62
Why is early ART initiation beneficial?
Improves survival, immune recovery, and reduces HIV transmission.
63
What is a recommended first-line ART regimen for most people with HIV?
Biktarvy (bictegravir/TAF/emtricitabine) once daily.
64
What is an alternative first-line regimen using dolutegravir?
Dolutegravir + TAF/FTC or TDF/FTC.
65
When can you use Dovato (DTG/lamivudine) as first-line?
If HIV RNA <500,000, no HBV co-infection, and resistance test available.
66
What counseling points should be included with ART initiation?
Adherence is critical. Discuss side effects, long-term therapy, and follow-up labs.
67
When should HIV resistance testing be done?
1) At entry into care, 2) At treatment failure, 3) Before ART changes in experienced patients.
68
Which genes are tested in standard genotyping?
Reverse transcriptase and protease genes.
69
When should integrase resistance be tested?
If failing an INSTI regimen or exposed to long-acting CAB-LA.
70
What viral load is needed for successful genotypic resistance testing?
≥500 copies/mL preferred, but may be attempted at >200 copies/mL.
71
Which antiretroviral class has a high genetic barrier to resistance?
Boosted PIs and second-generation INSTIs (e.g., dolutegravir, bictegravir).
72
Which class has a low genetic barrier to resistance?
NNRTIs (e.g., efavirenz) and NRTIs like lamivudine.
73
What is the preferred PEP regimen?
Truvada (TDF/FTC) + Tivicay (dolutegravir).
74
How long is PEP taken?
28 days.
75
When should PEP be started?
Within 72 hours of exposure.
76
What follow-up is required with PEP?
HIV testing at baseline, 4–6 weeks, 3 months, and 6 months.
77
What are the approved PrEP regimens?
1) Truvada, 2) Descovy (not for vaginal sex), 3) Apretude (CAB-LA injection every 2 months).
78
What labs are monitored in PrEP users?
HIV test every 3 months, renal function every 6–12 months, and STI screening.
79
What is the drug class of abacavir?
Nucleoside Reverse Transcriptase Inhibitor (NRTI)
80
What is the mechanism of action of abacavir?
Guanosine analogue that inhibits reverse transcriptase by DNA chain termination.
81
What is abacavir used for?
Treatment of HIV-1 infection.
82
What is the adult dosing for abacavir?
600 mg once daily or 300 mg twice daily.
83
What is the drug class of lamivudine?
NRTI
84
What is the mechanism of action of lamivudine?
Cytidine analogue that inhibits reverse transcriptase.
85
What is lamivudine used for?
Treatment of HIV and hepatitis B.
86
What is the adult dosing for lamivudine?
300 mg once daily.
87
What is the drug class of emtricitabine?
NRTI
88
What is the mechanism of action of emtricitabine?
Cytidine analogue that inhibits reverse transcriptase.
89
What is emtricitabine used for?
Treatment of HIV and hepatitis B.
90
What is the adult dosing for emtricitabine?
200 mg once daily.
91
What is the drug class of tenofovir disoproxil fumarate?
NRTI
92
What is the mechanism of action of tenofovir disoproxil fumarate?
Adenosine monophosphate analogue that inhibits reverse transcriptase.
93
What is tenofovir disoproxil fumarate used for?
Treatment of HIV and hepatitis B.
94
What is the adult dosing for tenofovir disoproxil fumarate?
300 mg once daily.
95
What is the drug class of tenofovir alafenamide?
NRTI
96
What is the mechanism of action of tenofovir alafenamide?
Adenosine analogue prodrug that inhibits reverse transcriptase with improved safety profile.
97
What is tenofovir alafenamide used for?
Treatment of HIV and hepatitis B.
98
What is the adult dosing for tenofovir alafenamide?
25 mg once daily.
99
What is the drug class of zidovudine?
NRTI
100
What is the mechanism of action of zidovudine?
Thymidine analogue that inhibits reverse transcriptase.
101
What is zidovudine used for?
Treatment of HIV; used in perinatal prophylaxis.
102
What is the adult dosing for zidovudine?
300 mg twice daily.
103
What is the drug class of stavudine?
NRTI
104
What is the mechanism of action of stavudine?
Thymidine analogue that inhibits reverse transcriptase.
105
What is stavudine used for?
Treatment of HIV (no longer recommended due to toxicity).
106
What is the adult dosing for stavudine?
Varies by weight; not commonly used.
107
What is the drug class of didanosine?
NRTI
108
What is the mechanism of action of didanosine?
Adenosine analogue that inhibits reverse transcriptase.
109
What is didanosine used for?
Treatment of HIV (rarely used due to toxicity).
110
What is the adult dosing for didanosine?
Weight-based dosing; not commonly used.
111
What is the drug class of efavirenz?
NNRTI
112
What is the mechanism of action of efavirenz?
Binds to allosteric site of reverse transcriptase to inhibit function.
113
What is efavirenz used for?
Treatment of HIV-1.
114
What is the adult dosing for efavirenz?
600 mg once daily on an empty stomach at bedtime.
115
What is the drug class of nevirapine?
NNRTI
116
What is the mechanism of action of nevirapine?
Allosterically inhibits reverse transcriptase.
117
What is nevirapine used for?
Treatment of HIV-1.
118
What is the adult dosing for nevirapine?
200 mg once daily for 14 days, then 200 mg twice daily.
119
What is the drug class of etravirine?
NNRTI
120
What is the mechanism of action of etravirine?
Allosterically inhibits reverse transcriptase.
121
What is etravirine used for?
Treatment-experienced patients with HIV-1.
122
What is the adult dosing for etravirine?
200 mg twice daily after meals.
123
What is the drug class of rilpivirine?
NNRTI
124
What is the mechanism of action of rilpivirine?
Inhibits reverse transcriptase by binding to an allosteric site.
125
What is rilpivirine used for?
Treatment of HIV-1 in patients with VL <100,000 and CD4 >200.
126
What is the adult dosing for rilpivirine?
25 mg once daily with food.
127
What is the drug class of doravirine?
NNRTI
128
What is the mechanism of action of doravirine?
Allosterically inhibits HIV-1 reverse transcriptase.
129
What is doravirine used for?
Treatment of HIV-1.
130
What is the adult dosing for doravirine?
100 mg once daily.
131
What is the drug class of darunavir?
Protease Inhibitor (PI)
132
What is the mechanism of action of darunavir?
Inhibits HIV protease, preventing cleavage of viral polyproteins.
133
What is darunavir used for?
Treatment of HIV-1.
134
What is the adult dosing for darunavir?
800 mg once daily with ritonavir or cobicistat.
135
What is the drug class of atazanavir?
PI
136
What is the mechanism of action of atazanavir?
Inhibits HIV protease, preventing viral protein processing.
137
What is atazanavir used for?
Treatment of HIV-1.
138
What is the adult dosing for atazanavir?
300 mg once daily with ritonavir 100 mg, taken with food.
139
What is the drug class of ritonavir?
PI used as a pharmacokinetic booster.
140
What is the mechanism of action of ritonavir?
Inhibits CYP3A4 to boost levels of other PIs.
141
What is ritonavir used for?
Boosting agent in ART regimens.
142
What is the adult dosing for ritonavir?
100–200 mg daily (as booster).
143
What is the drug class of dolutegravir?
INSTI
144
What is the mechanism of action of dolutegravir?
Inhibits integrase enzyme to prevent viral DNA integration.
145
What is dolutegravir used for?
Treatment of HIV-1.
146
What is the adult dosing for dolutegravir?
50 mg once daily.
147
What is the drug class of bictegravir?
INSTI
148
What is the mechanism of action of bictegravir?
Inhibits integrase to block HIV DNA integration.
149
What is bictegravir used for?
Treatment of HIV-1.
150
What is the adult dosing for bictegravir?
50 mg once daily (in Biktarvy).
151
What is the drug class of cabotegravir?
INSTI
152
What is the mechanism of action of cabotegravir?
Inhibits integrase, preventing integration of viral DNA.
153
What is cabotegravir used for?
HIV treatment and prevention (PrEP).
154
What is the adult dosing for cabotegravir?
600 mg IM every 2 months after oral lead-in.
155
What is the drug class of maraviroc?
CCR5 antagonist
156
What is the mechanism of action of maraviroc?
Blocks CCR5 receptor, preventing HIV entry into CD4 cells.
157
What is maraviroc used for?
Treatment of CCR5-tropic HIV-1.
158
What is the adult dosing for maraviroc?
300 mg twice daily (adjusted for drug interactions).
159
What is the drug class of ibalizumab?
Post-attachment inhibitor (monoclonal antibody)
160
What is the mechanism of action of ibalizumab?
Binds to CD4 receptor to block HIV entry post-attachment.
161
What is ibalizumab used for?
Treatment-experienced HIV-1 patients with multidrug resistance.
162
What is the adult dosing for ibalizumab?
IV infusion every 2 weeks.
163
What is the drug class of fostemsavir?
Attachment inhibitor
164
What is the mechanism of action of fostemsavir?
Binds gp120 to prevent HIV attachment to CD4 cells.
165
What is fostemsavir used for?
Treatment of HIV-1 in heavily treatment-experienced adults.
166
What is the adult dosing for fostemsavir?
600 mg twice daily.
167
What is the drug class of lenacapavir?
Capsid inhibitor
168
What is the mechanism of action of lenacapavir?
Inhibits multiple steps including capsid formation and integration.
169
What is lenacapavir used for?
Treatment of multidrug-resistant HIV-1.
170
What is the adult dosing for lenacapavir?
927 mg SC every 6 months after oral loading dose.
171
What enzyme does HIV use to convert RNA to DNA?
Reverse transcriptase.
172
What are the stages of the HIV lifecycle?
Attachment, fusion, reverse transcription, integration, transcription/translation, assembly, budding, maturation.
173
What happens to CD4 count and viral load over time without ART?
CD4 count declines, viral load increases.
174
What does CD4 count indicate?
Immune system status and need for OI prophylaxis.
175
What does HIV RNA (viral load) measure?
Effectiveness of ART and disease progression.
176
What baseline tests should be done before starting ART?
Resistance testing, HLA-B*5701, tropism assay, HBV/HCV screen, renal/hepatic function.
177
Which ARV class needs renal dose adjustment?
NRTIs, except abacavir.
178
Which ARVs interact with acid reducers?
Rilpivirine and atazanavir.
179
What are common side effects of efavirenz?
CNS effects and vivid dreams.
180
What side effect is associated with atazanavir?
Hyperbilirubinemia.
181
Which INSTI is known to cause weight gain?
Dolutegravir (and other INSTIs).
182
Which booster raises SCr without harming kidneys?
Cobicistat.
183
When should ART be started in HIV?
Immediately upon diagnosis, regardless of CD4 count.
184
What are first-line ART regimens?
Biktarvy, Dovato, DTG + TAF/FTC or TDF/FTC.
185
When should Dovato not be used?
If HIV VL >500,000, HBV co-infection, or resistance unknown.
186
When should rilpivirine not be used?
If VL >100,000 or CD4 <200.
187
When is resistance testing recommended?
At baseline, treatment failure, and before regimen changes.
188
What viral load is needed for resistance testing?
Preferably >500 copies/mL.
189
Which ARV classes have low genetic barriers to resistance?
NNRTIs and some NRTIs.
190
Which ARV classes have high genetic barriers to resistance?
Boosted PIs and INSTIs like dolutegravir/bictegravir.
191
What OI prophylaxis is started when CD4 <200?
PJP – TMP-SMX.
192
What OI prophylaxis is started when CD4 <100?
Toxoplasmosis.
193
What OI prophylaxis is started when CD4 <50?
MAC – Azithromycin.
194
What are the approved PrEP options?
Truvada, Descovy (not for vaginal sex), Apretude.
195
What is monitored in PrEP users?
HIV every 3 months, renal function, STIs.
196
What is the preferred PEP regimen?
Truvada + dolutegravir.
197
When should PEP be initiated?
Within 72 hours of exposure.
198
How long is PEP taken?
28 days.
199
What is the PEP testing schedule?
Baseline, 4–6 weeks, 3 months, and 6 months.
200
What is the preferred ART regimen in pregnancy?
Dolutegravir + TDF/FTC.
201
What ARV should be avoided in the first trimester?
Efavirenz.
202
Why is viral load near delivery important?
To assess risk for vertical transmission.
