While ketamine is generally considered safe in a clinical setting (Psychedelic.support, n.d.), there always exist the possibility of interactions with other medications or adverse effects for clients with existing conditions or predispositions for certain conditions.
Health professionals should be mindful of possible interactions and consult a physician or pharmacist on the possibility of interactions. Any change in medication should be overseen by a licensed medical provider. Since psychedelic medicines being used in a clinical setting is fairly new, not all contraindications or concomitant medications and supplements have been well studied (Pilecki et al., 2021).
The following conditions are contraindications for ketamine administration.
Under no circumstances should a client use ketamine if they have one of these conditions.
Allergic reaction to ketamine
History of ketamine abuse
History of stroke or brain aneurysm
Uncontrolled high blood pressure
Acute Angle Glaucoma
Uncontrolled thyroid disorder
History of mania/bipolar
Age 14 and under
Current diagnosis of schizophrenia, schizoaffective disorder, major depressive disorder with psychotic features, psychotic disorder
Pregnancy (women of childbearing age must use contraception if sexually active)
Note: While it is believed that ketamine doesn’t cause psychosis, mania, bipolar disorder, or borderline personality disorder, it is believed that ketamine can trigger an earlier onset of these underlying conditions (McIntyre et al., 2021).
These contraindications require further discussion with a physician.
Active or unstable substance use disorder that is not an indication for treatment will be evaluated on a case-by-case basis by the screening physician
History of heart disease
Dissociative identity disorder
History of psychosis
Current diagnosis of borderline personality disorder
Active or chronic severe suicidality and self-injury
History of seizure disorders
Actively breastfeeding: breastfeeding women may participate if they refrain from breastfeeding for 24 hours following ketamine administration
Sleep apnea (avoid if moderate to severe sleep apnea)
In addition to the above contraindications, there are additional contraindications for ketamine being used at low doses to treat depressive symptoms, such as with Spravato.
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Clients with these conditions must participate in ketamine-assisted therapy and not simply receive ketamine independent of therapy.
Current Dissociative Disorder*
Current moderate to severe Substance Use Disorder*
Under the age of adult consent*
PTSD
Bipolar Disorder
Eating Disorder
History of moderate to severe Substance Use Disorder
Borderline Personality Disorder
History of Psychosis
History of Dissociative Disorder
*Ketamine administration should not be conducted in a group setting with these conditions.
These are the contraindications specifically for Spravato.
Aneurysmal vascular disease (including thoracic and abdominal aorta, intracranial, and peripheral arterial vessels) or arteriovenous malformation
History of intracerebral hemorrhage
Hypersensitivity to esketamine, ketamine, or any of the excipients
In addition to the contraindications, if the client meets any of the following criteria, ketamine-assisted therapy is not recommended.
Under the age of adult consent in pertinent jurisdiction
Not fluent in the treating language of the health professionals present
There are myriad more potential drug interactions between ketamine and other substances. The following are selected based upon commonality or potential for severe risks in combination.
In collaboration with the treatment physician, prescribed psychiatric medications will be tapered by the referring physician and discontinued at least five half-lives before MDMA administration if considered safe and reasonable to do so. These medications include, but are not limited to:
Adderall (amphetamine / dextroamphetamine)
Benadryl (diphenhydramine)
Klonopin (clonazepam)
Lyrica (pregabalin)
Seroquel (quetiapine)
Valium (diazepam)
Xanax (alprazolam) (Drugs.com, 2022)
How should you talk to your clients about relative and absolute contraindications when it comes to ketamine-assisted therapy?
Because this is a new treatment, cautions must be taken to ensure there are no underlying mental or physical vulnerabilities that may put the client at a greater risk of adverse side effects or potential harms. Current standard contraindications draw from conditions that have been excluded due to potential for risk in research that has been done to validate the treatment. Also, because ketamine has psychoactive properties that cause a significant alteration in mood, thought, and behaviour during the acute effects, it’s important for individuals with mental health concerns to be evaluated for risk and appropriateness.
A relative contraindication is like an orange light/caution suggesting further evaluation and careful decision making weighing potential risks and benefits through informed consent.
An absolute contraindication is like a red light, meaning that this treatment is currently not recommend for someone with this particular condition.
As more research is done, inclusion and exclusion criteria typically broaden so that treatments can be proven safe enough for a broader range of people with a greater variety of underlying mental and physical health conditions.
Drugs.com (2022). Ketamine Interactions. https://www.drugs.com/drug-interactions/ketamine.html
McIntyre, R. S., Rosenblat, J. D., Nemeroff, C. B., Sanacora, G., Murrough, J. W., Berk, M., . . . Stahl, S. (2021). Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation. Am J Psychiatry, 178(5), 383-399. https://doi.org/10.1176/appi.ajp.2020.20081251
Pilecki, B., Luoma, J. B., Bathje, G. J., Rhea, J., Fraguada Narloch, V. (2021). Ethical and legal issues in psychedelic harm reduction and integration therapy. Harm Reduction Journal, 18(40). https://doi.org/10.1186/s12954-021-00489-1