University of California, San Francisco Logo

University of California, San Francisco | About UCSF | Search UCSF | UCSF Medical Center

Home > Treatment > Drug Dosing Toolkit > Tybost

cobicistat (Tybost)

Type of Drug: Pharmacokinetic Enhancer

A pharmacokinetic enhancer "boosts" certain other drugs by increasing their levels in the body and slowing their elimination.

Approved adult dosing

150 mg tablet

  • Once daily



Notes on taking this medication

  • Used as a booster of the integrase inhibitor elvitegravir and of certain protease inhibitors; must be taken with one of these
  • Should take with food
  • Tybost interacts with many other drugs; persons using Tybost with those drugs may need an adjustment to their dose of Tybost or the other drugs; consult your medical provider

Possible side effects

  • Nausea, diarrhea
  • Headache
  • Fatigue
  • Elevation in blood creatinine levels (this is used to assess kidney function; your provider will monitor creatinine)

See accompanying chart: Tips for Common Side Effects

My doctor's instructions

Scroll over drug name to see other names for the drug.