Ketamine is a medicine developed more than 50 years ago for anesthesia during surgery, and has been used for that purpose since that time in children, adults, and animals. More recently, ketamine has been found to be a valuable and highly effective treatment for depression, anxiety, and certain pain disorders.
Depression, anxiety, pain, and other forms of stress damage the communication system between areas of the brain responsible for memory, learning, and higher-order thinking. Ketamine is able to promote the materials necessary to make repairs to this damage within hours.
There are several. First is that it is an N-Methyl D-Aspartate (NMDA) receptor antagonist. Another is that it effects levels of the neurotransmitter glutamate. Third, is that ketamine enhances neuroplasticity with the neurons in the central nervous system.
Major depression, the depressed phase of bipolar disorder (bipolar depression), postpartum depression, anxiety, post-traumatic stress disorder (PTSD), obsessive compulsive disorder (OCD), pain syndromes such as fibromyalgia and complex regional pain syndrome (CRPS), also known as reflex sympathetic dystrophy (RSD), and addiction.
Uncontrolled blood pressure, unstable heart disease, untreated thyroid disease, active substance abuse, current manic phase of bipolar disorder, or active psychotic (hallucinations or delusions) symptoms.
The dose used for the treatment of mood and anxiety disorders is very low and safe. During ketamine treatments, blood pressure and heart rate may increase. This is monitored to ensure safety.
At this time, the majority of insurance companies do not pay for ketamine treatments for either pain or psychiatric conditions. Insurance companies view ketamine for these purposes as investigational or experimental.
What patients experience, depends on many factors, such as mode of administration (e.g., intravenous, intramuscular, intranasal, etc.), dose of ketamine, individual sensitivity to ketamine, amongst others. For most patients that receive subanesthetic doses to treat psychiatric and pain conditions the experience is pleasant and calming. It can induce a sense of disconnection to patients’ bodies, and a distortion of patients’ senses, such as vision, hearing, orientation to time, and others. For some, it can be disorienting, anxiety provoking, and unpleasant.
Although there is not a consensus of opinion on this matter amongst health care providers, subanesthetic dosing is considered less than 0.8-1mg/kg over 40 minutes to one hour. This is compared to anesthetic dosing of ketamine which is typically considered to be 2mg/kg bolused (meaning given all at once).
The main difference in these different delivery methods, are the bioavailability of ketamine, meaning the percentage of given ketamine that is absorbed into bloodstream. This doesn’t necessarily mean one method is more effective than another. Some physicians prefer one over the other, just as some patients prefer receiving one over the other. There is varying evidence for all methods of delivery for ketamine.