Dextromethorphan (Robitussin DM, Auvelity) and Ketamine Therapy | Tovani Health
Robitussin DM (Dextromethorphan) (also: Delsym, Auvelity) — NMDA receptor antagonist / sigma agonist (cough suppressant, antidepressant adjunct)
Verdict at Tovani Health
Compatible at cough doses; the NMDA mechanism overlap is the real concern, not serotonin syndrome.
Dextromethorphan and ketamine are compatible at standard OTC cough-syrup doses. The historically cited serotonin syndrome concern (DXM has minor serotonin reuptake activity) is less relevant with ketamine, which is not meaningfully serotonergic itself. The real consideration is mechanism overlap: DXM is also an NMDA receptor antagonist, just like ketamine. At cough doses the effect is negligible, but Auvelity (dextromethorphan-bupropion) for depression and recreational high-dose use produce meaningful NMDA blockade that overlaps with ketamine's mechanism.
If you take Robitussin DM regularly and are considering at-home ketamine therapy, the combination is safe with monitoring or dose adjustment. This page covers the brief pharmacologic context and what we do at intake.
How Robitussin DM interacts with ketamine
Dextromethorphan antagonizes NMDA glutamate receptors (overlapping ketamine), agonizes sigma-1 receptors, and inhibits serotonin reuptake. The NMDA overlap is what matters most for clinical planning around KAP; the serotonergic component is small and not a documented combination concern with ketamine.
What we do at intake
Disclose use, dose, and form (cough syrup, Auvelity for depression, recreational). We do not recommend high-dose DXM in the same week as a ketamine session.
Bottom line
Dextromethorphan and ketamine are compatible at standard OTC cough-syrup doses. The historically cited serotonin syndrome concern (DXM has minor serotonin reuptake activity) is less relevant with ketamine, which is not meaningfully serotonergic itself. The real consideration is mechanism overlap: DXM is also an NMDA receptor antagonist, just like ketamine. At cough doses the effect is negligible, but Auvelity (dextromethorphan-bupropion) for depression and recreational high-dose use produce meaningful NMDA blockade that overlaps with ketamine's mechanism.
Frequently Asked Questions
I take Auvelity. Can I also do ketamine?
We evaluate individually. The NMDA mechanism overlap and the bupropion component both matter. Often we recommend choosing one antidepressant pathway rather than stacking them.
Ready to find out if at-home ketamine fits your situation?
We’ll note that you’re on Robitussin DM (Dextromethorphan) 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 Anesthesia and Pain Therapy. Peltoniemi MA, Hagelberg NM, Olkkola KT, Saari TI.. Clinical Pharmacokinetics. 2016. PMID: 27028535
Comprehensive clinical pharmacokinetics/pharmacodynamics review of ketamine including CYP-mediated drug interactions (CYP3A4, CYP2B6).
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.