Is Ketamine Dangerous?
You must have heard about Ketamine, a powerful psychedelic medication used to treat treatment-resistant depression and post-traumatic stress disorder (PTSD). Some studies also indicate its beneficial effects in the treatment of obsessive-compulsive disorder (OCD), eating disorders, anxiety disorders, and addiction. Ketamine hydrochloride is used as an anesthetic during surgical procedures. Esketamine, a nasal spray, is used in the treatment of major depressive disorder (MDD). Due to its dissociative effects and feeling of detachment from surrounding and self, its recreational use has gained popularity as a "club drug."
However, there are certain side effects associated with the use of Ketamine. The public must be aware of these harmful effects. This blog will highlight the side effects, pharmacological effects, and toxicology of Ketamine.
Pharmacology of Ketamine
Ketamine is an NMDA receptor antagonist that alters the levels of glutamate. It also interacts with opioid, monoaminergic, and muscarinic receptors and affects voltage-sensitive calcium channels.
It is used as a rapid-acting anesthetic medication to induce a state termed as dissociative anesthesia. This state is characterized by analgesia, cardiovascular stimulation, normal or slightly enhanced muscle tone, normal pharyngeal and laryngeal reflexes, respiratory stimulation, and occasionally transient respiratory depression.
Ketamine exerts its antidepressant effects by enhancing inhibitory serotonergic pathways. Approximately one-tenth the dose needed for anesthetic purposes is required for antidepressant effects.
Ketamine absorption is very rapid, its bioavailability is 93%, and its distribution half-life is 1.95 min. Approximately 85-95% of administered Ketamine is eliminated from urine. Other routes of elimination are bile and feces.
When ketamine is administered properly in healthcare settings by a doctor, it has the least side effects and makes patients relaxed and calm. They experience relief from pain, sedation, and dissociation.
Recreational use of Ketamine at higher doses has potential hazards. Such individuals are at the risk of entering a "K-hole," characterized by unpleasant experiences of visual and auditory hallucinations associated with frightening detachment from reality.
Potential long term side effects of Ketamine
Although there is little evidence of long-term negative effects among people taking Ketamine in small doses, these effects are not negligible when a big dose is taken for an extended period. Chronic ketamine abuse has been known to damage people’s kidneys and liver. There is also a risk of bladder damage in such patients.
In contrast, people taking Ketamine at low doses for psychiatric purposes under a doctor’s supervision are thought to be safe. Some studies indicate Ketamine shows neuroplasticity, which has benefits that last for a long time. It could even improve cognitive functions in such patients.
Recreational and chronic use of Ketamine at higher doses may cause the following side effects:
Poor memory and concentration
Mood and personality changes
Abnormal liver function
Abnormal kidney functions
Poor sense of smell (if snorted)
Dependence of Ketamine
Ketamine bladder syndrome
Cognitive function deficit
Personal, family, and social problems.
Large and repeated doses of Ketamine may cause ketamine bladder syndrome characterized by ulceration of the bladder and inability to hold urine. Anyone having symptoms of ketamine bladder syndrome should immediately stop using ketamine and consult a healthcare professional.
Short time side effects of Ketamine
Sedation, confusion, transient rise in blood pressure, dream-like state, dissociation, memory and learning problems, and hallucinations, rate are short-term side effects of ketamine. These are usually completely reversible after 3-4 hours.
Ketamine As An Antidepressant; Side effects
Ketamine treatment in MDD, TRD, and PTSD has shown promising results. The negative cognitive effects are present transiently in acute and low doses of ketamine but consistently in long-term use of ketamine at high doses. Higher doses have detrimental effects on cognition; they can even cause psychosis. There is no evidence of cognitive impairment after MDD trials at low doses.
In a clinical study, patients with schizophrenia and psychosis have been shown to be at greater risk of developing cognitive deficits as compared to nonpsychotic patients. Cognitive deficits were only noticed in very frequent users (4 or more times/week).
Clinically, these results indicate doctors should be more cautious while administering ketamine in patients with psychosis, schizophrenia, psychotic depression, and ketamine-induced psychotic disorders.
Ketamine toxicity most commonly results from intramuscular and intravenous injections, oral consumption, smoking, and insufflation (snorting). It can also result from recreational and intranasal use.
Acute toxicity results in cardiovascular effects, features of physical harm, agitation, aggression, and dissociative features. Toxicity due to recreational use causes neurobehavioral effects like paranoid behavior and falling into a "K-hole."
Chronic toxicity causes neurotoxicity, urological and gastrointestinal problems, and dependence.
Oral ketamine based treatment under the supervision of a licensed healthcare professional has shown to be safe with fewer side effects than using ketamine with other administration route. A transient rise in blood pressure and nausea are expected after ketamine administration, but these
effects subside within 3-4 hours. Recreational use of ketamine at high doses is associated with short-term and long-term adverse effects.