Appendix B, Table 3. Characteristics of Nucleoside Reverse Transcriptase Inhibitors

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Appendix B, Table 3. Characteristics of Nucleoside Reverse Transcriptase Inhibitors
Generic Name
(Abbreviation)
Trade Name
Formulations Dosing Recommendationsa Elimination/ Metabolic Pathway Serum/ Intracellular Half-Lives Adverse Eventsb
Abacavir
(ABC)
Ziagen

Note: Generic tablet formulation is available.
Ziagen:
  • 300 mg tablet
  • 20 mg/mL oral solution
Generic:
  • 300 mg tablet
  • Also available as FDC with 3TC and ZDV/3TC
FDC Tablets that Contain ABC:c
  • Epzicom (ABC/3TC)
STRs that Contain ABC:d
  • Triumeq (DTG/ABC/3TC)
Ziagen:
  • ABC 600 mg PO once daily, or 
  • ABC 300 mg PO twice daily
See Appendix B, Tables 1 and 2 for dosing information for FDC tablets that contain ABC.
Metabolized by alcohol dehydrogenase and glucuronyl transferase

82% of ABC dose is excreted in the urine as metabolites of ABC.

Dose adjustment is recommended in patients with hepatic insufficiency (see Appendix B, Table 11).
1.5 hours/12–26 hours Patients who test positive for HLA-B*5701 are at the highest risk of experiencing HSRs. HLA screening should be done before initiating ABC.

For patients with a history of HSRs, rechallenge is not recommended.

Symptoms of HSRs may include fever, rash, nausea, vomiting, diarrhea, abdominal pain, malaise, fatigue, or respiratory symptoms (e.g., sore throat, cough, or shortness of breath).

Some cohort studies suggest an increased risk of MI with recent or current use of ABC, but this risk is not substantiated in other studies.
Emtricitabine
(FTC)
Emtriva
Emtriva:
  • 200 mg hard gelatin capsule
  • 10 mg/mL oral solution
FDC Tablets that Contain FTC:c
  • Descovy (TAF/FTC)
  • Truvada (TDF/FTC)
STRs that Contain FTC:d
  • Atripla (EFV/TDF/FTC)
  • Biktarvy (BIC/TAF/FTC)
  • Complera (RPV/TDF/FTC)
  • Genvoya (EVG/c/TAF/FTC)
  • Odefsey (RPV/TAF/FTC)
  • Stribild (EVG/c/TDF/FTC)
  • Symtuza (DRV/c/TAF/FTC)
Emtriva
Capsule:
  • FTC 200 mg PO once daily
Oral Solution:
  • FTC 240 mg (24 mL) PO once daily
See Appendix B, Tables 1 and 2 for dosing information for FDC tablets that contain FTC.
86% of FTC dose is excreted renally

See Appendix B, Table 11 for dosing recommendations in patients with renal insufficiency.
10 hours/>20 hours Minimal toxicity

Hyperpigmentation/skin discoloration

Severe acute exacerbation of hepatitis may occur in patients with HBV/HIV coinfection who discontinue FTC.
Lamivudine
(3TC)
Epivir

Note: Generic products are available.
Epivir:
  • 150 and 300 mg tablets
  • 10 mg/mL oral solution
Generic:
  • 150 and 300 mg tablets
  • Also available as FDC with ABC and ZDV
FDC Tablets that Contain 3TC:c
  • Cimduo (TDF/3TC)
  • Epzicom (ABC/3TC)
  • Temixys (TDF/3TC)
STRs that Contain 3TC:d
  • Delstrigo (DOR/TDF/3TC)
  • Dovato (DTG/3TC)
  • Symfi (EFV 600 mg/TDF/3TC)
  • Symfi Lo (EFV 400 mg/TDF/3TC)
  • Triumeq (DTG/ABC/3TC)
Epivir:
  • 3TC 300 mg PO once daily, or
  • 3TC 150 mg PO twice daily
See Appendix B, Tables 1 and 2 for dosing information for FDC tablets that contain 3TC.
70% of 3TC dose is excreted renally

See Appendix B, Table 11 for dose recommendations in patients with renal insufficiency.
5–7 hours/18–22 hours Minimal toxicity

Severe acute exacerbation of hepatitis may occur in patients with HBV/HIV coinfection who discontinue 3TC.
Tenofovir Alafenamide
(TAF)
Vemlidy

Note: Vemlidy is available as a 25-mg tablet for the treatment of HBV.
FDC Tablets that Contain TAF:c
  • Descovy (TAF/FTC)
STRs that Contain TAF:d
  • Biktarvy (BIC/TAF/FTC)
  • Genvoya (EVG/c/TAF/FTC)
  • Odefsey (RPV/TAF/FTC)
  • Symtuza (DRV/c/TAF/FTC)
See Appendix B, Tables 1 and 2 for dosing information for FDC tablets that contain TAF. Metabolized by cathepsin A 

See Appendix B, Table 11 for dosing recommendations in patients with renal insufficiency.
0.5 hours/150–180 hours

Renal insufficiency, Fanconi syndrome, and proximal renal tubulopathy are less likely to occur with TAF than with TDF.

Osteomalacia and decreases in BMD are less likely to occur with TAF than with TDF.

Severe acute exacerbation of hepatitis may occur in patients with HBV/HIV coinfection who discontinue TAF.

Diarrhea, nausea, headache

Greater weight increase has been reported with TAF than with TDF.

Tenofovir Disoproxil Fumarate
(TDF)
Viread

Note: Generic product is available.
Viread:
  • 150, 200, 250, and 300 mg tablets
  • 40 mg/g oral powder
Generic:
  • 300 mg tablet
FDC Tablets that Contain TDF:c
  • Cimduo (TDF/3TC)
  • Temixys (TDF/3TC)
  • Truvada (TDF/FTC)
STRs that Contain TDF:d
  • Atripla (EFV/TDF/FTC)
  • Complera (RPV/TDF/FTC)
  • Delstrigo (DOR/TDF/3TC)
  • Stribild (EVG/c/TDF/FTC)
  • Symfi (EFV 600 mg/TDF/3TC)
  • Symfi Lo (EFV 400 mg/TDF/3TC)
Viread:
  • TDF 300 mg PO once daily, or
  • 7.5 level scoops of oral powder PO once daily (dosing scoop dispensed with each bottle; one level scoop contains 1 g of oral powder).
Mix oral powder with 2–4 ounces of a soft food that does not require chewing (e.g., applesauce, yogurt). Do not mix oral powder with liquid.

See Appendix B, Tables 1 and 2 for dosing information for FDC tablets that contain TDF.
Renal excretion is the primary route of elimination.

See Appendix B, Table 11 for dose recommendations in patients with renal insufficiency.
17 hours/>60 hours Renal insufficiency, Fanconi syndrome, proximal renal tubulopathy

Osteomalacia, decrease in BMD             

Severe acute exacerbation of hepatitis may occur in patients with HBV/HIV coinfection who discontinue TDF.

Asthenia, headache, diarrhea, nausea, vomiting, flatulence
a For dose adjustments in patients with renal or hepatic insufficiency, see Appendix B, Table 11. When no food restriction is listed, the ARV drug can be taken with or without food.

b Also see Table 17.

c See Appendix B, Table 2 for information about these formulations.

d See Appendix B, Table 1 for information about these formulations.

Key: 3TC = lamivudine; ABC = abacavir; BIC = bictegravir; BMD = bone mineral density; DOR = doravirine; DRV/c = darunavir/cobicistat; DTG = dolutegravir; EVG/c = elvitegravir/cobicistat; EFV = efavirenz; FDC = fixed-dose combination; FTC = emtricitabine; HBV = hepatitis B virus; HLA = human leukocyte antigen; HSR = hypersensitivity reaction; MI = myocardial infarction; PO = orally; RPV = rilpivirine; STR = single-tablet regimen; TAF = tenofovir alafenamide; TDF = tenofovir disoproxil fumarate