Ketamine and Other Medications: What to Tell Your Clinician

Three groups stand out in ketamine's prescribing information: sedating medicines, stimulant-type medicines, and two older lung medicines. Antidepressants, mood stabilizers, and blood pressure medicines also come up often when people plan treatment.

Often, yes. In much of the research on ketamine for depression, people kept taking their usual antidepressant and ketamine was added on top.

In a 2020 multi-site trial, for example, participants had to be on a stable antidepressant dose for at least four weeks, and ketamine or a placebo was added to that ongoing treatment. Whether your own antidepressant should continue unchanged is a question for your prescriber and the ketamine clinician to answer together. MAOIs are a special case, covered below.

They can matter in two ways: safety and response. Taken together with ketamine, benzodiazepines add to sedation and can slow breathing, which is one reason dosing and monitoring are planned around them.

There is also some evidence that higher benzodiazepine doses may blunt ketamine's antidepressant effect. A 2020 analysis of 47 patients found that people taking higher daily doses were less likely to respond, and a 2023 analysis of a larger trial linked higher doses with less improvement on day one but not by day three. Both were after-the-fact analyses, so they suggest a link rather than settle it.

Stopping a benzodiazepine suddenly can be dangerous. The FDA warns that abrupt discontinuation or cutting the dose too quickly can cause withdrawal reactions, including seizures that can be life-threatening. Any adjustment, even to the timing of a dose around a session, should be planned with your prescriber.

Possibly, though the evidence is limited and mixed. Lamotrigine is thought to reduce the release of glutamate, a brain signaling chemical that ketamine also acts on, so researchers have asked whether it changes ketamine's effects.

In a 2000 study of healthy volunteers, a single dose of lamotrigine taken two hours before ketamine reduced some of ketamine's perceptual and dissociative effects. In a later trial in people with treatment-resistant depression, the same single pretreatment neither reduced side effects nor changed the antidepressant response. Neither study looked at people who take lamotrigine every day for a mood disorder or epilepsy, which is the usual situation.

If you take lamotrigine, list it with its dose, and do not stop or lower it on your own.

This combination needs particular care, and the decision belongs to your prescribers. Adding ketamine to an MAOI has generally been advised against because of concerns about raised blood pressure and serotonin syndrome.

A 2022 systematic review found only 12 published studies, covering 39 patients, in which ketamine was given alongside an MAOI. Blood pressure and heart rate rose in several cases, but the authors judged the change clinically insignificant in all but one patient, and they saw no hypertensive crisis or serotonin syndrome. They stressed that the numbers were small and the MAOI doses low, and that more research is needed.

MAOIs also interact strongly with other medicines. The labeling for amphetamine-type stimulants, for instance, warns that combining them with an MAOI can cause a hypertensive crisis, so a complete list matters even more if you take one.

Both belong on your list. Stimulants can add to ketamine's effect on blood pressure and heart rate, and blood pressure medicines show how well your pressure is controlled.

Amphetamine-type stimulants used for ADHD are sympathomimetic drugs, and their labeling notes that they can raise blood pressure and heart rate on their own. Ketamine's label advises closely monitoring vital signs when ketamine and sympathomimetic drugs are used together.

Ketamine's label does not single out blood pressure medicines, but they still matter. Ketamine commonly causes a short rise in blood pressure, and the label says ketamine is not for people in whom a sharp increase in blood pressure could be seriously harmful. Before your first session, the clinical team gives you instructions about medicines on treatment days; follow those, and check with your prescriber if anything conflicts with what they have told you.

Write it down rather than relying on memory, and bring it to the evaluation. Include: