Ketamine Drug Interactions: What to Tell Your Doctor

One extremely common class of medication may blunt the treatment. Most people are never asked about it.

Table of Contents

1. Ketamine Drug Interactions That Matter
2. Benzodiazepines, the Big One
3. Antidepressants and Mood Stabilizers
4. Blood Pressure and Heart Medication
5. Everything Else to Disclose
6. How to Prepare Your Medication List
7. FAQs About Ketamine Drug Interactions

Most people arriving for a ketamine assessment expect to be asked about their depression. Fewer expect a detailed medication review. The review is the more important half, and skipping it is one of the clearest signs of a clinic cutting corners. Ketamine drug interactions fall into two groups. Medications affecting how well treatment works, and medications affecting safety during a session. This page covers both and names nothing you should change on your own.

Ketamine Drug Interactions That Matter

Four groups matter most. Benzodiazepines may reduce ketamine’s antidepressant effect and are extremely commonly prescribed alongside depression. Blood pressure and cardiac medications matter since ketamine reliably raises blood pressure during a session. Sedatives and opioids increase sedation when combined. Some mood stabilizers, particularly lamotrigine, have been discussed as potentially reducing the dissociative and possibly the therapeutic effect. Everything else you take still needs disclosing, since interactions are assessed as a whole picture rather than a checklist. None of this means any of these medications rules you out. It means your clinician needs to know before rather than after.

Benzodiazepines, the Big One

The interaction most worth understanding, since so many people with depression and anxiety take one. This class includes alprazolam, lorazepam, clonazepam and diazepam, sold under names including Xanax, Ativan, Klonopin and Valium. The concern. Several studies and clinical reports suggest regular benzodiazepine use may reduce or blunt ketamine’s antidepressant response. The proposed reason involves opposing effects on the excitation and inhibition balance that ketamine acts on. Benzodiazepines increase GABA activity, which suppresses neuronal firing, and ketamine’s effect appears to depend on a burst of that firing. How strong is the evidence. Reasonable rather than definitive. Findings are mixed and the effect is not universal. Plenty of people on benzodiazepines respond well. What it does not mean. It does not mean stopping. Benzodiazepines carry a genuine physical withdrawal risk, and abruptly stopping can be dangerous, including seizures. Any change requires a prescriber and usually a gradual taper over weeks or months. What to do. Tell your ketamine clinician exactly what you take, the dose and how often. They will discuss it with your prescriber. Options might include timing sessions relative to doses, a planned taper managed by your prescriber, or proceeding as you are and monitoring response. If a course produces no response and nobody asked about benzodiazepines, that is worth raising, as covered in our post on what happens if ketamine does not work.

Antidepressants and Mood Stabilizers

SSRIs and SNRIs. Usually continued during ketamine treatment. Ketamine is usually given alongside rather than instead of them, and Spravato was approved only as an add-on until January 2025. MAOIs. An older class needing specific attention from blood pressure effects. Disclose clearly. This is a prescriber-level decision. Lamotrigine. A mood stabilizer that has been discussed as potentially reducing ketamine’s dissociative effects and possibly its therapeutic ones. Evidence is limited and mixed. Worth disclosing, not worth acting on independently. Lithium. Usually compatible and requires disclosure alongside monitoring. Antipsychotics. Disclose. A history of psychosis affects candidacy separately from the medication itself. Bupropion, mirtazapine, trazodone and others. All disclosed as part of the full list. Never stop or reduce any of these on your own. Discontinuation effects are real across several classes and stopping abruptly can worsen symptoms considerably. Anyone who tells you to stop your antidepressant before ketamine without involving your prescriber is doing something wrong.

Blood Pressure and Heart Medication

The safety half of the picture rather than the effectiveness half. Ketamine reliably raises blood pressure and heart rate during a session. That rise is expected, temporary, and monitored. It matters if you have uncontrolled hypertension, a history of heart attack or stroke, an aneurysm or vascular malformation, significant arrhythmia, or uncontrolled thyroid disease. Disclose everything you take for these, including beta blockers, ACE inhibitors, calcium channel blockers and diuretics. Do not skip a dose of blood pressure medication before a session except where in particular instructed. People sometimes assume they should. The opposite is usually true. Expect your blood pressure to be taken before dosing and monitored during the session. A clinic that does not is not managing the most predictable physiological effect of the drug it is giving you.

Everything Else to Disclose

The list people leave things off.

• Opioid pain medication, increased sedation when combined
• Sleep medication, including z-drugs like zolpidem
• Muscle relaxants
• Stimulants for ADHD, which affect blood pressure
• Thyroid medication
• Anticoagulants
• Alcohol, honestly, including how much and how often
• Cannabis, including legal and medical use
• Recreational drugs, particularly other dissociatives
• Herbal supplements, especially St John’s wort, kava and valerian
• Over-the-counter medication taken regularly

Two of these get omitted most: alcohol and cannabis. Both interact with sedation and both are relevant. Clinicians are not there to judge you. They cannot plan safely without an accurate picture, and an omission that seems minor to you may not be.

How to Prepare Your Medication List

Fifteen minutes before your appointment saves a great deal. Write everything down rather than relying on memory. Name, dose, how often, how long you have taken it. Photograph the bottles and bring the photos. Labels carry details people misremember. Include what you take occasionally, not just daily medication. Include past psychiatric medications with rough dates and what happened. This matters for insurance authorization on Spravato, covered in our post on Spravato. Bring your prescriber’s contact details and expect to be asked for consent to contact them. Ask your pharmacy for a printout if the list is long. Most will produce one. Our post on choosing a ketamine clinic covers what a thorough screening looks like.

FAQs About Ketamine Drug Interactions

Do benzodiazepines affect ketamine treatment? There is reasonable evidence that regular use may reduce or blunt ketamine’s antidepressant effect, though findings are mixed and many people on them still respond. Disclose exactly what you take. Never stop a benzodiazepine on your own, since withdrawal carries genuine risk including seizures. Do I need to stop my antidepressant before ketamine? Usually no. Ketamine is usually given alongside existing antidepressants rather than instead of them. Any change is a decision for your prescriber, never something to do independently, since several classes carry discontinuation effects. Can I have ketamine treatment if I take blood pressure medication? Usually yes, with disclosure and monitoring. Ketamine raises blood pressure temporarily during a session, so your medication and your readings matter. Do not skip a dose before a session except where in particular instructed, since the opposite is usually correct. Should I tell them about cannabis or alcohol? Yes, honestly, including how much and how often. Both affect sedation and both are clinically relevant. This is one of the most commonly omitted disclosures and one of the more useful ones. Nobody is assessing your character. What about supplements and over-the-counter medicine? Disclose them. St John’s wort, kava and valerian all have relevant effects, and regular over-the-counter use counts. Bring the actual bottles or photographs of the labels rather than trying to recall names.

Bring Your Full List

A proper medication review is part of the assessment. Bring everything, including what you would rather not mention. Call (770) 817-9200 or see our ketamine therapy page. Atlanta Ketamine Clinic, 5755 North Point Parkway Suite 256, Alpharetta, GA 30022. Reviewed by Angelo Sambunaris, M.D., Atlanta Ketamine Clinic. This article is general information, not medical advice. Never start, stop or change any medication without speaking to your prescriber. If you are having thoughts of suicide or self-harm, call or text 988 to reach the Suicide and Crisis Lifeline, available 24 hours a day.