Talking Ketamine Podcast

This episode dives into a 2026 case report revealing a surprising drug interaction: ketamine, used for pain management, induced the liver to accelerate the breakdown of critical immunosuppressant medications in a heart transplant recipient. Transplant patients rely on a delicate balance, where drugs like tacrolimus and sirolimus prevent organ rejection. However, these drugs are metabolized by specific liver enzymes (CYP3A4), making them vulnerable to interactions.

In this case, a patient receiving ketamine for post-surgical pain experienced a dramatic drop in immunosuppressant levels, placing his transplanted heart at risk. Doctors responded by drastically increasing the doses, but the drug concentrations barely budged. The ketamine was essentially "teaching" the liver to clear the drugs faster, a phenomenon known as enzyme induction. The peak effect occurred a week after ketamine was started, followed by a slow recovery over three weeks.

The episode emphasizes the importance of vigilant monitoring when ketamine is used in patients on narrow therapeutic range medications, and that monitoring should continue for three weeks after ketamine is discontinued to catch any potential rebound effects.

Resources:

Stojanova, J., Murnion, B., Burrows, F., Carlos, L., Mizuno, T., Nadai, T., Helsby, N., Muthiah, K., & Day, R. (2026). Continuous Subcutaneous Ketamine Infusion May Induce Tacrolimus and Sirolimus Clearance: A Case Report. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy, 46(e70150). https://doi.org/10.1002/phar.70150

Imagine standing in your bathroom, staring down at your current prescription bottles, terrified that your daily SSRI or SNRI might block the effects of your upcoming ketamine treatment. In Episode 62, we tackle “The Combination Question” by breaking down a highly practical 2026 brief report from Yale by Curran, Hardy, and colleagues.

Looking at real-world data from 332 patients with Treatment-Resistant Depression (TRD), researchers uncovered a “beautifully boring” but life-altering reality: there is absolutely no significant difference in ketamine’s clinical success regardless of what background antidepressant class a patient is currently taking. We explore the neurobiology behind this phenomenon. Traditional oral antidepressants act like “traffic cops” trying to route signals efficiently on a broken, congested monoamine highway. Ketamine, however, bypasses that system entirely; it acts on the glutamate system to release BDNF, essentially deploying a “construction crew” to pave an entirely new, high-speed neural bypass. Because they operate on completely different biological tracks, they do not interfere with one another.

This data offers massive relief. It proves patients do not have to endure agonizing, dangerous drug tapers or risk a severe depressive crash just to clear their system before starting ketamine. Psychiatry is finally moving away from the exhausting merry-go-round of drug “swapping” and entering a much more compassionate era of “layering” treatments.

Reference

Curran, E., Hardy, M., Katz, R., Rhee, T. G., & Wilkinson, S. T. (2026). Concurrent SSRI, SNRI, or other antidepressant use not associated with differential outcomes in ketamine or esketamine treatment. The Journal of Clinical Psychiatry, 87(2), 25br16294. https://doi.org/10.4088/JCP.25br16294

Imagine knowing exactly what someone is feeling, but your brain forces you to second-guess yourself before you can even react. That is the reality of Treatment-Resistant Depression (TRD), which creates massive “cognitive friction” in social situations. Episode 61 breaks down a fascinating 2026 computational psychiatry study by Yoldas and colleagues that proves severe depression doesn’t break your ability to read emotions—it just hits the brakes on your processing speed.

Using Hierarchical Drift Diffusion Modeling (HDDM), researchers discovered that TRD patients are perfectly accurate at Facial Emotion Recognition (FER). Their delay is caused by psychomotor slowing and excessively wide “decision boundaries”—meaning their depressed brains require an abnormal amount of evidence before making a choice. The most incredible part? Within just 2 to 4 hours of a single ketamine infusion, patients became significantly faster, normalizing their decision-making speeds. The data shows that ketamine doesn’t need to teach the brain to read emotions again; it simply takes the foot off the cognitive brakes.

Reference:

Yoldas, Z., Cantenys, W., Tronche, M., Hardy, S., Samion, L., Imbault, M., Schmidt, L., & Fossati, P. (2026). Ketamine and facial emotion recognition in treatment-resistant depression: a computational account. OSF Preprints. https://doi.org/10.31234/osf.io/7vb32_v1

In Episode 60, we step outside the realms of mental health and anesthesia to explore a groundbreaking 2026 study by Korkmaz and colleagues that asks a shocking question: can ketamine fight cancer directly? We dive into an in vitro study focusing on HT-29 colorectal cancer cells, exploring the potential of repositioning this common anesthetic in the oncology world.

Cancer cells are notoriously hard to kill because they deactivate apoptosis—the body’s natural cellular suicide program. This study reveals that ketamine effectively flips this self-destruct switch back on, showing a marked increase in early apoptosis. It alters the delicate balance of key proteins by downregulating Bcl-2, which protects the tumor, and upregulating Bax, which tears the cancer cell apart. At the same time, ketamine acts as an anti-proliferative agent, stopping the cancer cells from aggressively multiplying.

How does a dissociative anesthetic achieve this? Molecular docking simulations and gene expression profiling show that ketamine interacts with NMDA and EGFR receptors, disrupting vital signaling pathways like ERK and AKT. While these findings are currently limited to petri dishes rather than human clinical trials, they open the door to a fascinating future where the anesthetics used during tumor-removal surgeries might actively help fight the disease itself.

Reference:

Korkmaz, I. F., Elgun, T., Aktas, Ç., Gündeğer, E., & Yurttas, A. G. (2026). Ketamine induces apoptosis and inhibits proliferation in HT-29 colorectal cancer cells. Biomedicines, 14(4), 907. https://doi.org/10.3390/biomedicines14040907

For decades, neurology has viewed adult brain damage as a relatively permanent state, offering mostly compensatory therapies to help patients adapt to their deficits. But Episode 59 explores a 2026 systematic review by Leon-Rojas and Sacks-Zimmerman that flips the script: could subanesthetic ketamine actually act as a powerful cognitive enhancer?

We unpack the paradox of using a dissociative anesthetic to sharpen the mind. The secret lies in looking past the acute intoxication phase—the temporary “construction zone”—to the structural remodeling that follows. We explore ketamine’s two-phase neuroprotective mechanism: acting first as a “fire extinguisher” to block NMDA receptors and stop toxic glutamate floods (excitotoxicity), and second as “fertilizer” by releasing BDNF to sprout new neural bridges (synaptogenesis).

While animal models show a staggering 93.2% success rate in restoring cognitive functions like working memory and spatial learning, the review’s single human study on Huntington’s disease showed short-term cognitive impairment. We discuss why timing and context are everything: to truly harness this drug, the biological “window of neuroplasticity” must be actively paired with rigorous, targeted neurorehabilitation to guide the brain’s rewiring.

Reference:

Leon-Rojas, J. E., Mascialino, G., Vinueza Mera, L., Hinojosa-Figueroa, M. S., Navas Arias, C. F., Cadena Barberis, E. D., & Sacks-Zimmerman, A. (2026). Ketamine as a potential cognitive enhancer in neurological disorders: Evidence from preclinical and clinical studies. Frontiers in Neurology, 17, 1786249. https://doi.org/10.3389/fneur.2026.1786249

For decades, the clinical focus of treating Major Depressive Disorder has been on alleviating profound sadness. However, traditional monoaminergic antidepressants often fall short of treating anhedonia—the absolute absence of pleasure—and can even cause “emotional blunting” by placing an artificial ceiling on a patient’s dopamine-driven joy. In Episode 58, we explore a landmark 2026 systematic review by Faisal and colleagues that synthesizes 13 neuroimaging studies to show how ketamine acts not just as an antidepressant, but as a “pro-joy intervention.”

We break down the brain’s reward architecture into the “Engine” (primitive structures like the striatum and nucleus accumbens) and the “Steering Wheel” (the prefrontal cortex). Chronic depression causes the dendritic spines connecting these regions to wither, leaving the engine dead. But the neuroimaging data is staggering: functional MRI (fMRI) measuring the BOLD signal during the Monetary Incentive Delay task shows that ketamine rapidly reactivates the striatum’s response to reward anticipation.

We also dive into PET scan data, revealing how ketamine modulates the 5-HT1B serotonin receptor—acting like a “bouncer” to remove the brakes from the dopamine system. Ultimately, this episode offers profound vindication for patients stuck in the gray zone: anhedonia is not a moral failing or a psychological attitude, but a physical deficit in the brain’s wiring that ketamine is structurally capable of repairing.

Reference:

Faisal, H., Le, G. H., Kwan, A. T. H., Wong, S., Cheung, W., Dri, C. E., Cao, B., Rhee, T. G., Bargiota, S., Lo, H. K. Y., Shen, B., Guillen-Burgos, H. F., & McIntyre, R. S. (2026). Effect of ketamine on reward processing in depressive disorders: A systematic review of neuroimaging studies. CNS Spectrums. https://doi.org/10.1017/S109285292610087X

In Episode 57, we explore a groundbreaking 2026 study out of Hungary by Koncz and colleagues that challenges the foundation of modern psychiatry: do you actually have to “trip” to heal? For years, the pharmaceutical industry has searched for a sanitized, at-home version of ketamine, hoping that R-ketamine (arketamine) could deliver neuroplasticity without the intense psychotomimetic effects of standard S-ketamine (esketamine).

By utilizing quantitative EEG (qEEG) signals, researchers discovered the “Gamma-Delta Shift”—the electrical signature of the brain actively rewiring. S-ketamine acts like a controlled forest fire: it triggers a massive, high-frequency “gamma storm” (the trip) which creates a massive cellular energy debt. This debt forces a mandatory “delta rebound” during deep sleep, which is when the actual physical remodeling and synaptic plasticity occur.

The shocking twist? Even at four times the normal dose, arketamine completely failed to trigger this shift. This perfectly mirrors its recent failure in human clinical trials, where it did not show a statistically significant antidepressant effect compared to a placebo. The data draws a clear line: you cannot bypass the chaotic exertion phase and still get the structural repair. The altered state isn’t a side effect to be engineered away; it is a necessary feature of the cure.

Reference:

Koncz, S., Pothorszki, D., Papp, N., Pál, D., & Bagdy, G. (2026). Differential effects of ketamine enantiomers on EEG parameters including the gamma-delta shift phenomenon. British Journal of Pharmacology, 1-15. https://doi.org/10.1111/bph.70399

In Episode 56, we explore a fascinating 2026 pharmacokinetics study by Otto and colleagues that completely changes how we view oral ketamine for Treatment-Resistant Depression (TRD). When taken orally, ketamine hits a massive biological roadblock: the liver’s “first-pass effect”. The liver acts as an aggressive tollbooth, metabolizing almost all of the parent drug and transforming it into a high volume of a metabolite called (S)-norketamine before it reaches the wider bloodstream.

Using advanced Pharmacokinetic-Pharmacodynamic (PKPD) modeling, researchers discovered a mind-bending reality. While intravenous ketamine drips rely on the original parent drug to drive the therapeutic high, the subjective experience of an oral pill is almost entirely driven by its metabolite, (S)-norketamine. Because this metabolite is a “clunkier key” with a lower affinity for NMDA receptors, it requires a massive volume to overwhelm the system and produce the necessary psychotomimetic effects.

The study’s simulations reveal a major clinical hurdle: standard oral doses (like 0.2 or 0.45 mg/kg) fall significantly short of matching the proven therapeutic experience of an IV drip. To achieve those same effects, oral doses must be drastically increased to approximately 1.0 mg/kg. We discuss what this means for the future of TRD treatment, the need for new safety monitoring strategies due to delayed absorption, and the unsettling realization that the pills we swallow aren’t always the chemicals that heal us.

Reference:

Otto, M. E., Jacobs, G. E., van Mechelen, J. C., Borghans, L. G. J. M., van Hasselt, J. G. C., & Aulin, L. B. S. (2026). Pharmacokinetics and pharmacodynamics of intravenous and oral (S)-ketamine: Investigating metabolite contribution to subjective effects. British Journal of Clinical Pharmacology, 1-12. https://doi.org/10.1002/bcp.70503

Bipolar depression creates an agonizing clinical trap: patients are paralyzed by severe lows, yet traditional antidepressants take weeks to work and carry the terrifying risk of an “affective switch”—triggering a manic episode or rapid cycling. In Episode 55, we explore a 2026 review by Queissner and colleagues showing how ketamine and esketamine rewrite the rules by bypassing serotonin and targeting the brain’s glutamate “gas pedal”.

We unpack the staggering data: an odds ratio of 10.68 for rapid relief, with the REAL-ESK study showing zero cases of manic switching in real-world patients using intranasal esketamine. The episode dives deep into the biology, exploring Rizzo’s 2025 discovery of ketamine’s dual mechanism (NMDA and mu-opioid receptor modulation) that specifically targets anhedonia by restoring dopamine to the brain’s reward center. Finally, we discuss why ketamine isn’t a solo act—and how foundational mood stabilizers like lithium act as a safety net that synergizes with ketamine to spark central neuroplasticity and structural brain repair.

Reference:

Queissner, R., Fellendorf, F., & Reininghaus, E. Z. (2026). Ketamine as an NMDA-modulating therapy in bipolar disorder: Rationale and evidence. Frontiers in Psychiatry, 17, 1777402. https://doi.org/10.3389/fpsyt.2026.1777402

For decades, medicine has sold us the comforting “light switch” theory: under general anesthesia, we simply cease to exist for a few hours. But in Episode 54, we unpack Bruno Tonetto’s terrifying and fascinating 2026 paper, “Conscious Under Anesthesia,” which argues that we have confused the silence of the body with the absence of the mind.

We explore the “broken speaker” analogy, revealing how paralytics trap patients in a silent body, while premedications like Midazolam act as chemical memory wipers (anterograde amnesia) to ensure the experience is forgotten. The most chilling evidence? The Isolated Forearm Technique, where researchers block the paralytic from reaching one arm, revealing that up to a third of paralyzed, “unconscious” patients can squeeze a hand to answer complex questions—yet remember absolutely nothing upon waking.

Finally, we tackle the “Ketamine Paradox.” As an approved anesthetic that triggers hyper-vivid, mystical experiences, ketamine completely breaks the traditional “production model” of the brain. Instead, Tonetto argues for the “constraint model,” suggesting the brain is not a turbine generating consciousness, but a “reducing valve” filtering it. When ketamine unplugs the sensory inputs, the filter breaks, and the mind expands.

Reference:

Tonetto, B. (2026). Conscious under anesthesia: What the clinical evidence actually shows. Project: Return to Consciousness. https://brunoton.github.io/return-to-consciousness/exports/pdf/cua.pdf