Overview
Ketamine is a dissociative anesthetic used for surgical procedures, treatment-resistant depression, and chronic pain. As an NMDA receptor antagonist, it blocks glutamate, the primary excitatory neurotransmitter in the brain. With depression, this leads to the brain creating new pathways extremely quickly that can guide someone out of negative loops in their thoughts and feelings. It’s also used recreationally, with high doses inducing a state that’s colloquially referred to as a “K-hole” in which someone experiences severe dissociation that temporarily immobilizes them.
Long-term complications of Ketamine include:
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Cystitis. When ketamine is broken down and filtered into the urine, its byproducts burn the bladder lining and replaces healthy tissue with thick scar tissue. This fibrosis leads to the bladder’s capacity shrinking as far down as the size of a marble, which can cause pain, bleeding, and frequent urination. In extreme cases, this can cause a backup into the kidneys that causes renal failure.
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Cramps. While the exact cause isn’t yet established, researchers are exploring toxicity in the bile ducts and gastrointestinal spasms after taking ketamine.
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Cognitive decline. Although we noted above that ketamine can help open up new pathways for treatment-resistant depression, it can also impair short-term memory and executive functioning. It’s also been tied to persistent episodes of depersonalization, paranoia, and psychosis.
The brain is able to build tolerance to ketamine quickly, so while overdoses from ketamine are rare, a high quantity mixed with other depressants can be fatal. For instance, ketamine and alcohol have a compounding effect that can trigger fatal respiratory depression, so someone can simply stop breathing while dissociated or sedated from the mix. When ketamine is mixed with stimulants like cocaine, which someone might try as a means of offsetting the sedation of ketamine, the combination places high strain on the cardiovascular system which leads to elevated heart rates and blood pressure.