Paxlovid and Ketamine Therapy | Tovani Health
Paxlovid (Nirmatrelvir / Ritonavir) — Antiviral (COVID-19) with strong CYP3A4 inhibition
Verdict at Tovani Health
Strong CYP3A4 inhibition can raise ketamine exposure; we space the 5-day course from sessions.
Paxlovid alongside ketamine warrants individual evaluation. The ritonavir component is one of the most potent CYP3A4 inhibitors in clinical use, and ketamine is metabolized primarily by CYP3A4 and CYP2B6. Combining them can substantially raise ketamine plasma levels and prolong its half-life. Paxlovid is a short course (typically 5 days), so the practical fix is timing: we do not run sessions during the course or for several days after. After the typical washout, you become eligible again.
If you take Paxlovid regularly and are considering at-home ketamine therapy, the combination is depends on your specific situation. This page covers the brief pharmacologic context and what we do at intake.
How Paxlovid interacts with ketamine
Ritonavir potently inhibits CYP3A4 (the inhibition is the design of the booster), and the inhibition persists for several days after the last dose. With CYP3A4 suppressed, ketamine clearance drops, raising peak plasma levels and total exposure. This means a standard ketamine dose could behave like a much larger one.
What we do at intake
Disclose any current or recent Paxlovid course. We do not run sessions during the 5-day course or within 72 hours after. If you have COVID symptoms severe enough to need Paxlovid, the session is postponed regardless of timing.
Bottom line
Paxlovid alongside ketamine warrants individual evaluation. The ritonavir component is one of the most potent CYP3A4 inhibitors in clinical use, and ketamine is metabolized primarily by CYP3A4 and CYP2B6. Combining them can substantially raise ketamine plasma levels and prolong its half-life. Paxlovid is a short course (typically 5 days), so the practical fix is timing: we do not run sessions during the course or for several days after. After the typical washout, you become eligible again.
Ready to find out if at-home ketamine fits your situation?
We’ll note that you’re on Paxlovid (Nirmatrelvir / Ritonavir) at intake. The eligibility check takes 5 minutes and gives you an honest answer about whether at-home ketamine fits your specific situation.
FL and NJ residents only. Benjamin Soffer, DO — Tovani Health.
Sources
The verdict and clinical guidance on this page are based on the following peer-reviewed literature and FDA prescribing information.
- Ketamine: A Review of Clinical Pharmacokinetics and Pharmacodynamics in Anesthetic and Pain Therapy. Peltoniemi MA, Hagelberg NM, Olkkola KT, Saari TI. Clinical Pharmacokinetics. 2016. PMID: 27028535
Reviews CYP-mediated drug interactions affecting ketamine clearance; CYP3A4 inhibitors substantially raise ketamine exposure.
Clinically reviewed
Reviewed by Benjamin Soffer, DO on May 16, 2026. Dr. Soffer is a board-certified physician (American Board of Internal Medicine) licensed in Florida and New Jersey, prescribing at-home ketamine therapy through Tovani Health.
This page is general information about how this medication interacts with at-home ketamine therapy at Tovani Health. It is not a substitute for medical advice from your prescribing physician about your specific situation. Always discuss medication changes with the doctor who prescribed them.