What the FDA labels say about taking them together
Cobicistat and darunavir
Cobicistat's FDA label of February 10, 2026 names darunavir in its contraindications section; the darunavir label PlainMeds reads does not name cobicistat. The cobicistat label: “DRUG INTERACTIONS TYBOST, in combination with atazanavir or darunavir, can alter the concentration of drugs metabolized by CYP3A or CYP2D6.”
Check it at the source: the cobicistat FDA label on DailyMed (effective February 10, 2026, Gilead Sciences, Inc.); the darunavir FDA label on DailyMed (effective August 29, 2025, Janssen Products LP).
What does the cobicistat label say about darunavir?
Cobicistat label, contraindicationsCONTRAINDICATIONS The concomitant use of TYBOST with atazanavir or darunavir and the following drugs is contraindicated due to the potential for serious and/or life-threatening events or loss of therapeutic effect [see Drug Interactions (7.3) and Clinical Pharmacology (12.3) ].
Cobicistat label, drug interactionsDRUG INTERACTIONS TYBOST, in combination with atazanavir or darunavir, can alter the concentration of drugs metabolized by CYP3A or CYP2D6.
Cobicistat label, warnings and precautionsMonitor serum phosphorus in patients with or at risk for renal impairment. ( 5.2 ) TYBOST in combination with more than one antiretroviral that requires pharmacokinetic enhancement (i.e., two protease inhibitors or elvitegravir in combination with a protease inhibitor) is not recommended. ( 5.4 ) Use with HIV-1 protease inhibitors other than atazanavir or darunavir administered once daily is not recommended. ( 5.4 ) Coadministration with drugs or regimens containing ritonavir is not recommended.
Source: FDA drug label (Tybost), Gilead Sciences, Inc., effective February 10, 2026 (SPL set 3784c35c-e87f-410c-900b-8fd6313c6010), via openFDA; the full label on DailyMed
What does the darunavir label say about cobicistat?
Darunavir's label (effective August 29, 2025) does not name cobicistat in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (PREZISTA), Janssen Products LP, effective August 29, 2025 (SPL set 814301f9-c990-46a5-b481-2879a521a16f), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Cobicistat | Darunavir | |
|---|---|---|
| Labeled for | HIV | HIV |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $1.16 per tablet 600 mg tablet |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once