Ketamine: Beyond Anesthesia

“I have seen a light at the end of the tunnel. ” This is the well-known phrase that the mass media, through popular culture, have sent us as a representation of what some consider “out-of-body experiences” or “near death”. But, beyond supernatural considerations, there is a well-known anesthetic drug that may be behind some of these experiences: ketamine.

Some of the people who report these experiences of extracorporeal escape and perception of it – from a point of view remote from the physical body itself – were at that moment undergoing surgery under the sedative effects of ketamine.

We are talking about a drug that has powerful psychotropic properties; Those popular phenomena of escape and tunnel travel at the time of death thus found scientific logic.

Ketamine is capable, like other recreational drugs, of generating perceptual dissociation phenomena in which the composition of perceptions, in whatever sensory modality – including the perception of time and that of oneself as a whole, but differentiated being – occurs in a disorderly or illogical manner.

For this reason, the final perceptual phenomenon emerges distorted, intermingled ; intermodal sensory transfers occur (such as hearing a color, tasting a sound, etc.) and, in somewhat more extreme cases, the directional sense of time changes or reverses, expands or contracts, and the person stops recognizing their own limits physical and bodily members.

Multisensory hallucinations – visual, auditory, gustatory, tactile and olfactory – then occur frequently, as does the ‘ in situ’ experience of true spatial and temporal episodes far from the temporal-spatiality of the individual’s present moment and place – phenomenon informally known as ‘travel’.

At controlled and therapeutic doses, such as on an operating table, these psychoactive effects are reversible and transient, while ingested in different doses, ketamine can induce a deep dissociative state (popularly known as the “K hole”).

It can also induce the perception of non-real things, people and situations to an extreme difficult to reconcile with one’s own reality, and at great risk of causing sequelae or promoting psychotic outbreaks in people biologically predisposed to it.

This problem made the use of ketamine a highly controversial issue, and for this reason its legal use in humans has been restricted in recent years – sometimes used only as a last resort-, remaining as the anesthetic of choice in large veterinary surgery. animals.

What is ketamine?

Ketamine is a type of medication used essentially for the induction and maintenance of anesthesia in human surgery, both adult and pediatric. It has the ability to induce a trance-like state, while also providing :

• Pain relief.
• Sedation.
• Memory loss.

In addition to this surgical use, which is also extensive to veterinary science, ketamine is used in the management of chronic pain and for rapid sedation in the Intensive Care Unit (ICU).

While the drug exerts its effects, a relative preservation of cardiac, respiratory and various reflex function is observed. Usually, it is not until the effects begin to weaken that undesirable side reactions appear, such as :

• Elevation of blood pressure.
• Respiratory depression
• Involuntary muscle contractions
• Agitation.
• Confusion.
• Hallucinations

These are the effects attributable to this drug when it is used, illegally and for recreational purposes, at higher doses or administered in a way other than strictly clinical ones.

Alternative uses of ketamine

Despite its bad reputation, the political and legal impediments that surround this substance -now widely considered an addictive drug-, the reluctance of the clinical, pharmaceutical and patient community itself, numerous investigations have been carried out. fact about alternative uses.

Its mechanism of action is to selectively block the well-known NMDA receptor (N-methyl-d-aspartate), which in addition to globally reducing brain activity also hinders memory retention and temporarily alleviates depressive symptoms.

This action, together with its pharmacokinetics and pharmacodynamics, makes ketamine a powerful anesthetic and sedative; very practical for medical applications, but it also makes it a strong dissociative drug, precisely because of its link with the NMDA receptor.

In addition to the aforementioned uses – considered ‘typical’ in clinical practice – there are other less exploited uses for which ketamine seems to be an effective alternative :

• As an adjunct in the treatment of depression.
• As a hypnotic or sleep inducer.
• To reduce the incidence of epileptic seizures.
• As a neuroprotector, especially in cases of brain damage.
• To collaborate in mitigating the effects of post-traumatic stress disorder and also in the treatment of obsessive-compulsive disorder.
• As a reducer of asthmatic symptoms.

Ketamine and depression

Of all the new and surprising uses attributable to ketamine, the one that seems to be arousing the most interest, and the one that, according to all the indications, will receive clinical application and commercialization the earliest, is its use as a complement to antidepressant therapy. 

In this regard, and far from the widely accepted monoaminergic hypothesis that for so many decades has fueled research and the generation of antidepressant drug families, the real new news is that, precisely, the most benefited are those who have responded the worst to the common antidepressants.

That is, ketamine works where other antidepressants do not; it is working well in people whose depression is resistant to common drugs. A result that very few scientists thought of contemplating.

Sometimes the solutions are much closer than we think; our eagerness for great deeds makes us look to new horizons when, possibly, we have an answer right in front of us.