Ketamine is not free of side effects.
Ketamine gained notoriety in the 90's as a recreational drug, referred to as "special K" and associated with veterinary anesthesia. In the past decade, though, it has emerged as a powerful analgesic and antidepressant in the right setting.
Used in very low doses - doses lower than those used for anesthesia - ketamine reduces pain and resets the pain centers of the brain. It allows for neuroplasticity, reorganization of pain programming in the nervous system.
For depression and post-traumatic stress disorder (PTSD), ketamine is also helpful when traditional medication options have failed.
As depression and PTSD frequently accompany chronic pain, low-dose ketamine becomes a powerful tool for patients.
At the initial visit, after arriving at an anatomic understanding of the patient's pain process, we will discuss all treatment options.
We consider ketamine when there is:
- Hypersensitivity of the nervous system
- Severe pain that has not responded to other medications
- Opioid dependence with a desire to taper off
- Coexisting depressed mood
More information is available in our informed consent.
For the first ketamine visit, we want to determine:
- 1) How does the patient tolerate the medication?
Ketamine may cause an out-of-body experience. Some patients describe kaleidoscope vision, or an Alice in Wonderland type of experience.
- 2) Are there side effects (eg. elevated blood pressure)
- 3) Is it helpful for pain and/or mood? If so, how helpful, and how long does it last?
To do this, we start an IV in a monitored setting and administer 10mg of ketamine. We see how the patient responds and measure vital signs. Possible responses:
- 1) Anxiety - patient is uncomfortable with the experience. We then give midazolam IV to sedate the patient and end the experience.
- 2) Analgesia without dissociation - we have found the ideal therapeutic dose to reduce pain and not cause an out-of-body experience.
- 3) Dissociation - this is the out-of-body experience which most patients find quite pleasant.
- 4) Nothing. Some patients require a higher dose, so an additional 5-10mg is given.
For 2 and 3 above, based on the dose required, we start an infusion which is run over 45 minutes.
Many patients work with a mental health specialist who prepares an audio track for use during the infusion and follows up with them after.
Based on the response to the initial infusion, we may set up a series of infusions (usually weekly x8 weeks) or prescribe for home use (strictly controlled).
Is ketamine the future of antidepressants?
Currently there is no scientific data on the safety of long-term use of ketamine. We know short-term side effects from decades of use in surgical anesthesia, but chronic daily use or frequent infusions are not well studied, and long-term effects are not known.