Isoniazid (INH) and Ketamine Therapy | Tovani Health
INH (Isoniazid) (also: Laniazid) — Antimycobacterial (TB treatment + latent TB prophylaxis; MAO-A inhibitor)
Verdict at Tovani Health
INH has real MAO-A inhibition; we follow the same operational framework as other MAOIs.
Isoniazid alongside ketamine requires individual evaluation. INH is the standard latent TB prophylaxis (common for healthcare workers, immigrants from high-prevalence countries, and BCG-vaccinated patients) and a TB treatment cornerstone. The relevant pharmacology for KAP: INH has documented MAO-A inhibitor activity that has produced tyramine-cheese-reaction case reports and serotonin syndrome interactions with serotonergic drugs. Same operational framework we apply to phenelzine, linezolid, and methylene blue: at-home unmonitored KAP is not appropriate while on active INH. Also: INH causes B6 (pyridoxine) deficiency that can produce peripheral neuropathy — patients should be on supplemental B6 throughout INH therapy.
If you take INH regularly and are considering at-home ketamine therapy, eligibility depends on your specific situation — we evaluate case by case. This page covers the brief pharmacologic context and what we do at intake.
How INH interacts with ketamine
INH inhibits mycolic acid synthesis in mycobacteria. Independently inhibits monoamine oxidase (both A and B) and CYP2C19/2E1. The MAO inhibition is what makes the ketamine sympathomimetic stack a real concern. Hepatotoxicity is the dose-limiting toxicity for the TB indication.
What we do at intake
Disclose dose and indication (latent TB prophylaxis vs active TB treatment). We do not run sessions during active INH therapy. After completing the course and a 14-day washout, you become eligible. Continue your B6 supplementation as prescribed.
Bottom line
Isoniazid alongside ketamine requires individual evaluation. INH is the standard latent TB prophylaxis (common for healthcare workers, immigrants from high-prevalence countries, and BCG-vaccinated patients) and a TB treatment cornerstone. The relevant pharmacology for KAP: INH has documented MAO-A inhibitor activity that has produced tyramine-cheese-reaction case reports and serotonin syndrome interactions with serotonergic drugs. Same operational framework we apply to phenelzine, linezolid, and methylene blue: at-home unmonitored KAP is not appropriate while on active INH. Also: INH causes B6 (pyridoxine) deficiency that can produce peripheral neuropathy — patients should be on supplemental B6 throughout INH therapy.
Ready to find out if at-home ketamine fits your situation?
We’ll note that you’re on INH (Isoniazid) 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.
- Safety of Ketamine Augmentation to Monoamine Oxidase Inhibitors in Treatment-Resistant Depression. Veraart JKE, Smith-Apeldoorn SY, et al.. Journal of Clinical Psychiatry. 2022. PMID: 36300995
Clinically reviewed
Reviewed by Benjamin Soffer, DO on May 22, 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.