Harm Reduction

At high doses, ketamine has the potential to be lethal. That being said, lethal doses for humans have been estimated using rodent data as being 11.3 mg/kg of intravenously delivered ketamine, far higher than what is considered the high range for anesthetic induction, which is typically 1- 4.5 mg/kg IV (Ben-Shlomo et al., 2001; Hansen et al., 1988).

In a recreational setting, ketamine can cause serious or fatal accidents caused by its perceptual alterations (Lodge & Mercier, 2015; Nutt et al., 2007). Ketamine deaths in recreational settings also tend to be linked with polysubstance use (Corkery et. al, 2021).

Some clients may be hesitant when learning about the dissociative properties of ketamine; however, ketamine’s dissociative effects are an essential part of the ketamine therapy model that should not be feared or avoided (Dore et al., 2019). An early study conducted to investigate whether dissociative adverse effects of ketamine were related to antidepressant efficacy observed that these effects predict a robust and sustained antidepressant response and, therefore, they are essential clinical biomarkers to predict the effectiveness of ketamine (Luckenbaugh et al., 2014).

Particularly with the medicines used in psychedelic-assisted therapy, clients may start treatment with some inaccurate information about the psychedelic medicine being used. The internet (particularly social media platforms) is full of misinformation about psychedelic medicines, their effects, adverse effects, and anticipated experiences.

In the case of ketamine, there is a widespread public belief that ketamine is a “horse tranquilizer.” While ketamine is used in veterinary medicine, it is important to share with clients the vast human-centred use of ketamine, including its past and present applications, as well as its benefits in psychedelic-assisted therapy and the treatment of treatment-resistant depression.

Although ketamine can be used to reduce suicidality, a rare side effect of ketamine use is an increased risk of suicidal thoughts and thus risk of self-harm or suicide. Clients should undergo a suicide risk assessment to determine if ketamine is appropriate (Pilecki et al., 2021).

Because of the possibility of liver damage, it requires the performing of liver function tests periodically for those clients receiving repeated treatment (Ceban et al., 2021).

Chronic high doses of ketamine have shown in human and animal models to have neurotoxic potential; these doses, however, are larger and more frequent than those in medical ketamine treatment and this risk is one associated with cases of substance use disorders (Nogo et al., 2022).

Ketamine is a drug that—when used recreationally—is a known drug of abuse that can cause social and physical harm. The potential for addiction and abuse should be kept in mind when screening clients. Although the evidence on an increased risk of substance use disorders after ketamine administration is scarce, appropriate clinical usage is largely believed not to represent a risk for the development of dependence or abuse (Dore et al., 2019; McIntyre et al., 2021).

As discussed in Fundamentals of Psychedelic-Assisted Therapy, some clients express a desire for wanting to keep their psychedelic experiences alive. In the course, we provide some recommendations for how to keep the psychedelic experience alive without the need for ingesting medicines recreationally outside of a clinical setting.

Flashbacks with ketamine are rare, however some people can experience them. Flashbacks occur after a ketamine session where an individual might experience a hallucination or memory from their time under the effects of the medicine. Flashbacks can be disorienting or frightening (Perel & Davidson, 1976).

Long-term use of ketamine can also lead to kidney and bladder toxicity and other damage to the urinary tract. However, this condition appears to be associated with long-term recreational use (Jalil & Gupta, 2012; Srirangam & Mercer, 2012).

Ketamine addiction is possible if clients regularly consume ketamine outside of a clinical setting. Clients should be made aware of the addiction potential for ketamine and how termination of ketamine abuse can result in withdrawal symptoms (American Addition Centers, 2022).