Ketamine Side Effects: What New Data Means for Patients

The News: Clinicians Push for Smarter, Faster Protocols

A new perspective published in Psychiatric Times is calling on prescribers to move more decisively when treating patients with treatment-resistant depression (TRD) using NMDA receptor antagonists — a drug class that includes both IV ketamine and intranasal esketamine (Spravato). The piece emphasizes optimizing dosing, switching agents sooner when response is inadequate, and tracking outcomes systematically using tools like the PHQ-9 depression scale. Crucially, the authors also shine a spotlight on side effect profiles and discontinuation rates — two factors that patients and families often struggle to get clear answers about before starting treatment.

NMDA receptor antagonists have become a significant part of the TRD treatment landscape over the past several years. Esketamine received FDA approval in 2019 specifically for treatment-resistant depression and, later, for major depressive disorder with acute suicidal ideation. IV racemic ketamine is used widely off-label. Both have demonstrated rapid antidepressant effects — sometimes within hours — which sets them apart from conventional antidepressants that can take weeks to show results. But that speed comes alongside a side effect burden that is meaningfully different from SSRIs or SNRIs, and understanding that burden matters enormously for informed consent and patient retention.

What the Evidence Says About Side Effects

The most commonly reported side effects of NMDA antagonists during acute treatment sessions include dissociation, dizziness, nausea, increased blood pressure, and sedation. These effects are typically short-lived — most resolve within two hours of administration — and are managed in clinical settings through supervised monitoring periods. However, the Psychiatric Times article underscores that side effect burden is not uniform across patients, and that clinicians need to be tracking these effects systematically rather than relying on informal patient reports.

Dissociation, in particular, deserves attention. It is both a commonly reported experience and a phenomenon that patients respond to very differently. For some, mild dissociative effects feel tolerable or even therapeutically interesting. For others, they are distressing enough to prompt early discontinuation. The clinical literature shows that dissociation during esketamine sessions is dose-dependent, meaning that dose optimization — rather than simply stopping treatment — can sometimes resolve tolerability problems without sacrificing efficacy.

Discontinuation rates are a less-discussed but equally important metric. In clinical trials for esketamine, dropout rates due to adverse events were generally in the range of 5–10%, but real-world rates can differ. Patients who discontinue early often do so in the first few sessions, before therapeutic benefit has had time to accumulate. This is one reason the Psychiatric Times authors advocate for proactive side effect management and faster clinical decision-making: waiting too long to adjust a protocol can result in patients leaving treatment prematurely, before they've had a fair trial.

Blood pressure elevation is another consideration that receives clinical attention. Both IV ketamine and intranasal esketamine can transiently raise blood pressure during and shortly after administration. For most patients this is manageable and expected, but it does mean that patients with pre-existing hypertension or cardiovascular concerns require particularly careful screening and monitoring. Reputable ketamine clinics and certified esketamine treatment centers routinely monitor blood pressure throughout sessions — this should be a baseline expectation, not a premium feature.

Why This Matters for Patients Evaluating Ketamine Therapy

For patients and families researching ketamine or esketamine as a treatment option, this kind of clinical guidance matters on several practical levels.

First, it reinforces that side effects, while real and sometimes uncomfortable, are largely predictable and time-limited. The majority of what you may experience during a ketamine infusion or esketamine session happens in-session and resolves within a couple of hours. You should not be driving yourself home — but you also should not expect to feel impaired the next morning. Understanding this arc in advance can help reduce anxiety going into a first session.

Second, the emphasis on systematic outcome tracking is a useful signal for provider selection. Clinics that are routinely measuring your depression scores with validated tools like the PHQ-9 or MADRS, and that are actively asking about side effects at each visit, are demonstrating a higher standard of care. This kind of structured monitoring is what allows a clinician to make timely, data-informed decisions — like adjusting your dose or switching protocols — rather than reacting only when things go noticeably wrong.

Third, the article's call for faster protocol switching when response is inadequate is patient-empowering information. If you complete an induction course (typically six sessions over two to three weeks for esketamine) without meaningful improvement, that is a clinically relevant data point. You are not obligated to continue indefinitely with a protocol that isn't working. Good providers will discuss with you when to pivot, and this guidance suggests the field is moving toward earlier, more decisive reassessment rather than passive waiting.

Finally, this piece is a reminder that the NMDA antagonist category is still evolving. Researchers and clinicians are actively refining best practices — dosing intervals, patient selection criteria, side effect management strategies, and long-term maintenance protocols are all areas of ongoing study. The evidence base is stronger than it was five years ago, but it is not finished. That is worth holding in mind as you weigh your options: ketamine therapy is evidence-supported for TRD, but it is not a one-size-fits-all solution with a fully standardized protocol across every provider.

The Bottom Line

The Psychiatric Times guidance on NMDA antagonist side effect profiles and discontinuation rates is a useful reminder that ketamine therapy, done well, is an active clinical process — not a passive one. Providers should be measuring, adjusting, and communicating. Patients and families should feel empowered to ask questions and expect structured answers. As the field continues to mature, this kind of data-driven, patient-centered approach is what separates high-quality ketamine care from the lower end of the market.

You can read the original article at Psychiatric Times.