Recommendations for the Use of Antiretroviral Drugs in Pregnant Women with HIV Infection and Interventions to Reduce Perinatal HIV Transmission in the United States

The information in the brief version is excerpted directly from the full-text guidelines. The brief version is a compilation of the tables and boxed recommendations.

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Cobicistat (Tybost, COBI)

Last Updated: December 7, 2018; Last Reviewed: December 7, 2018

Excerpt from Table 10

Note: When using FDCs, refer to other sections in Appendix B and Table 10 for information about the dosing and safety of individual drug components of the FDC during pregnancy.

Excerpt from Table 10
Generic Name
Trade Name
Formulation Dosing Recommendationsa Use in Pregnancy








COBI (Tybost)
  • COBI 150 mg
ATV/COBI (Evotaz):
  • ATV/COBI 300 mg/50mg tablet

  • EVG 150 mg plus COBI 150 mg plus FTC 200 mg plus TAF 10 mg tablet
DRV/COBI (Prezcobix):
  • DRV/COBI 800 mg/150 mg tablet
EVG/COBI/FTC/TDF (Stribild):
  • EVG 150 mg plus COBI 150 mg plus FTC 200 mg plus TDF 300 mg tablet

  • DRV 800 mg plus COBI 150 mg plus FTC 200 mg plus TAF 10 mg tablet
Standard Adult Doses
COBI (Tybost):
  • As an alternative PK booster with ATV or DRV: 1 tablet (150 mg) once daily with food.
ATV/COBI (Evotaz):
  • 1 tablet once daily with food.
  • 1 tablet once daily with food.
DRV/COBI (Prezcobix):
  • 1 tablet once daily with food
  • 1 tablet once daily with food
PK in Pregnancy:
  • Based on limited data COBI exposure and pharmaco-enhancing effect on DRV and EVG are markedly reduced in pregnancy.
  • No data are available on the pharmaco-enhancing effect of COBI on ATV.
  • When coadministered with COBI, TAF exposure is not significantly different between pregnancy and the postpartum period.
Dosing in Pregnancy:
  • While COBI exposure exposure is markedly reduced during pregnancy, higher than standard doses have not been studied. The Panel recommends RTV as the preferred pharmaco-enhancer for PIs and INSTIs during pregnancy until more data are available on COBI activity during pregnancy.
  • For guidance about the use of combination products in pregnancy, please see the specific sections on other components (i.e., FTC, TAF, TDF, ATV, DRV, EVG).

Low placental transfer to fetus.b

Insufficient data to assess for teratogenicity in humans. No evidence of teratogenicity in rats or rabbits.

Use of COBI-boosted ATV, DRV, or EVG is not recommended in pregnancy.

a Individual ARV drug dosages may need to be adjusted in patients with renal or hepatic insufficiency (for details, see the Adult and Adolescent Guidelines Appendix B, Table 8).
b Placental transfer categories—Mean or median cord blood/maternal delivery plasma drug ratio:
          High: >0.6
          Moderate: 0.3–0.6
          Low: <0.3

Key to Acronyms: ATV = atazanavir; COBI = cobicistat; DRV = darunavir; DRV/r = darunavir/ritonavir; EFV = efavirenz; EVG = elvitegravir; FDC = fixed-dose combination; FTC = emtricitabine; INSTIs = integrase strand transfer inhibitors; PIs = protease inhibitors; PK = pharmacokinetic; RTV = ritonavir; TAF = tenofovir alafenamide; TDF = tenofovir disoproxil fumarate

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