II. Indications

  1. HIV Infection (combination therapy)
  2. Chronic Hepatitis B Infection (Coinfected with HIV)

III. Mechanism

  1. Nucleoside Reverse Transcriptase Inhibitor
  2. Emtricitabine is 5-Fluorothiocytidine (FTC), a substituted analog of cytosine (similar to Lamivudine)

IV. Precautions

  1. Risk of severe HBV exacerbation on discontinuation
    1. Monitor for at least 2 months after discontinuation

V. Medications

  1. Emtricitabine (Emtriva, Coviracil)
    1. Capsules: 200 mg
    2. Solution: 10 mg/ml
  2. Emtricitabine with Tenofovir
    1. Tenofovir Disopoxil (TDF) and Emtricitabine (Truvada)
    2. Tenofovir Alafenamide (TAF) and Emtricitabine (Descovy)
  3. Emtricitabine with Tenofovir AND Efavirenz (an NNRTI)
    1. Tenofovir Disopoxil (TDF) and Emtricitabine and Efavirenz (Atripla)

VI. Dosing: HIV Infection

  1. See HIV Preexposure Prophylaxis
  2. Used in combination with other HIV agents (e.g. Tenofovir)
  3. Adult (or child weight >33 kg)
    1. Emtricitabine 200 mg orally daily
  4. Child (weight <33 kg)
    1. Age 0 to 3 months: 3 mg/kg orally daily
    2. Age >3 months: 6 mg/kg (up to 240 mg) orally daily
    3. Weight >33 kg: See Adult dosing

VII. Dosing: Chronic Hepatitis B Coinfection with HIV (not FDA approved)

  1. Emtricitabine 200 mg orally daily AND
  2. Tenofovir
    1. CrCl >=30 ml/min: Tenofovir Alafenamide (Descovy) 25 mg orally daily
    2. CrCl >=60 ml/min: Tenofovir Disopoxil (Truvada) 300 mg orally daily

VIII. Dosing: Renal (Adult)

  1. CrCl 30 to 49 ml/min
    1. Take 200 mg capsule orally every 48 hours (or 120 mg oral solution daily)
  2. CrCl 15 to 29 ml/min
    1. Take 200 mg capsule orally every 72 hours (or 80 mg oral solution daily)
  3. CrCl <15 ml/min or Hemodialysis
    1. Take 200 mg capsule orally every 96 hours (or 60 mg oral solution daily)

IX. Adverse Effects: Emtricitabine alone

  1. See nRTI for adverse effects attributed to the class
  2. Minimal specific adverse effects and well tolerated
  3. Hyperpigmentation of palms and soles
  4. Hepatitis B infection flares on withdrawal of medication

X. Adverse Effects: Emtricitabine with Tenofovir (Truvada, Descovy)

  1. See Tenofovir
  2. Start-up syndrome (Nausea, Abdominal Pain, Flatulence, Headache) which typically resolves after the first month
  3. Hepatitis B Virus flare
    1. Associated with abrupt cessation of Antiretroviral therapy
  4. Acute Renal Failure
    1. Risk when Truvada is combined with multiple dose or high dose NSAIDs
    2. May be less risk with Descovy (uses Tenofovir TAF instead of TDF)

XI. Safety

  1. Avoid in Lactation
  2. Pregnancy Category B
    1. Among preferred NRTI agents in pregnancy
    2. Combination with Tenofovir Disopoxil (Truvada) is also considered safe in pregnancy (preferred combination)

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Related Studies

Cost: Medications

emtricitabine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
truvada (on 7/20/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
TRUVADA 200 MG-300 MG TABLET Generic $0.56 each
descovy (on 1/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
DESCOVY 200-25 MG TABLET $66.13 each