All About Ketamine
Ketamine’s history begins with phencyclidine. Phencyclidine was first synthesized in 1956 by the chemists at Parke Davis Company, who first confirmed its unique and fascinating properties.
Soon phencyclidine became a safe and effective anesthetic in human beings. However, it was also considered undesirable owing to its side effect which was the prolonged and intense delirium.
There was intensive research to discover a shorter analog of phencyclidine which delivers the same anesthetic effects, but causes less delirium. Calvin Stevens who was an organic chemist and a Parke Davis consultant developed ketamine in 1962. Ketamine was well known as CI-581 in those days. Ketamine is chemically (+)-2-(2-chlorophenyl)-2-(methylamino) cyclohexanone (CAS No. 6740-88-1 for base, 1867-66-9 for hydrochloride.)
In 1996, Corssen and Domino published a paper mentioning the potential uses of ketamine, its efficacy, and safety in 130 patients to whom ketamine was given. They confirmed ketamine relieves pain and alters consciousness to a limited time which can be increased by repeating the dosage. Ketamine is much safer and desirable than phencyclidine. Ketamine maintains the stability of the heart and respiratory system while maintaining anesthesia and analgesia/ pain-relieving action.
Mode of administration
Ketamine is safe and effective via various routes such as:
· IV/ Intravenous/ injections into the blood vessels called veins
· IM/ intramuscular/ injected into muscles
· Oral
· Nasal
· Subcutaneous/ injected below the skin
· Epidural/ injected in the lower back
Out of the above routes, IV administration is the best as ketamine’s bioavailability via the IV route is 100%.
*Bioavailability is the dosage of the medicine that is available for utilization by your body. When you have medicine, some of it might get lost on the way due to filtration processes. Bioavailability is the final amount of medicine that is available for the desired effects.
IM/ Intramuscular bioavailability of ketamine is 93%. It is the choice in emergencies and uncooperative patients.
Ketamine mainly exerts the following effects:
· Sedation/ relaxing and inducing sleep
· Analgesia/ pain-relieving
· Maintains the stability of vital systems such as the heart and respiratory system
Ketamine was historicially mainly used for:
· Prolonging anesthesia
· Critical care medicine
Beginning in 2002 Ketamine has received a lot of attention for it’s use to treat:
Treatment-resistant depression
*Depression is the constant feeling of lifelessness/ boredom/ worthless/ suicidal tendency at times
· PTSD/ Post Traumatic Stress Disorder
· Schizophrenia
· Psychological/nerve related pain-relief
The psychological benefits of ketamine are owing to its dissociative nature and dissociation refers to a feeling of dissociation of the mind from the body.
Side effects of ketamine
When you take ketamine under the guidance of your doctor, ketamine is generally safe. Inadvertent use could invite problems.
Here’s a list of the potential side effects of ketamine:
· Hypersalivation/ excess saliva production
· Hyperreflexia/ overactive reflexes such as a twitching tendency
· Transient clonus/ uncontrollable, rhythmic, shaking movements due to involuntary muscle contraction
· Dizziness
· Nausea/ vomiting sensation
· Vomiting
· Dissociative symptoms such as a feeling of intoxication, altered vision/ hearing/ other sensations, thought disorder, misinterpretation, poor speech, etc.
· Urinary system diseases such as inflammation of the bladder
Ketamine blocks the sensory inputs to the higher centers of CNS thus blocking the emotional response to stimuli and the process of memory and learning.
Ketamine abuse/ inadvertent use could lead to digestive tract related symptoms such as pain in the upper stomach and injury to the liver. Though these effects resolve on their own in about 2 hours, long-term use can cause pronounced and persistent side effects such as schizophrenia-like symptoms, cognitive impairment (disturbed thought and learning process,) and poor psychological well-being.
Ketamine needs to be used with caution especially while using it with other medicines/ substances that alter mood and behavior such as alcohol, opioids, benzodiazepines, and cannabis.
Very rarely it could cause the following side effects:
· Palpitation/ you feel a high heartbeat
· Tachycardia/ increased heart rate
· High blood pressure
The side effects are dose-dependent too and usually reverse once you stop the dosage. Follow your doctor’s guidelines for better results.
Over the past 50 years, countless patients have benefited greatly from ketamine. We anticipate many more exciting discoveries in the next 50 years…
Ketamine is effective, safer, and offers multiple but effective options for use. Ketamine is well studied and has an impressive benefit-to-risk ratio.
Reference
· https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5126726/
· https://www.who.int/medicines/areas/quality_safety/6_2_Update.pdf
· https://www.mayoclinic.org/diseases-conditions/delirium/symptoms-causes/syc-20371386
