Ketamine
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https://medicalxpress.com/news/2022-10-ketamine-depression-mechanism-antidepressant-revealed.html
Researchers from Inserm, CNRS, Sorbonne University and clinicians from the AP-HP and at Paris Brain Institute identified one of the mechanisms explaining the ketamine effect as an antidepressant. Ketamine, usually used as an anesthetic, was administered to patients with severe resistant depression.
This treatment led patients to present an increased ability to overcome their negative beliefs about themselves and the world when researchers presented them positive information. These results, published in JAMA Psychiatry, open new therapeutic avenues for the management of antidepressant-resistant mood disorders.
Depression is the most common psychiatric disorder: it is estimated that 5 to 15% of the French population will experience a major depressive episode during their lifetime. All age groups and all social backgrounds are affected.
The disease is characterized by sadness and loss of hedonic feelings that positive events do not improve. Depressed patients progressively develop negative beliefs about themselves, the world, and the future, that may develop into suicidal thoughts. These negative beliefs remain even when the patient receives positive information.
About one-third of people with depression do not respond to the most prescribed antidepressants, leading to a diagnosis of treatment-resistant depression (TRD). For these people, finding new and effective therapies is a priority.
Ketamine, a commonly used anesthetic, has been shown to influence resistant depression. While conventional antidepressant treatments take time to be efficient (on average three weeks), ketamine has a rapid antidepressant effect, only a few hours after administration. The mechanisms associated with this fast-acting antidepressant effect are still unknown.
In the suite of the study, TRD patients received three administrations of ketamine at a subanesthetic dose (0.5 mg/kg over 40 minutes) in one week.
For the sake of comparisons, 0.5mg/kg is a pretty good dose that will provide systemic analgesia without inducing unconsciousness. I always found it to be a useful adjuvant to an epidural when the epidural wasn't quite good enough. I'd usually combine it with about 0.5ug/kg of fentanyl. To induce anesthesia, a dose of about 2 mg/kg is enough. For kids who are not going to be cooperative with starting an IV or getting a mask held on their face, 5 mg/kg
in a "dart"intramuscularly is sufficient to make the rugrat compliant with being moved and transported to the OR.Ketamine, in lower doses, is called a "dissociative anesthetic." In other words, it sort of disconnects your lower brain from your cortex, so that you might be aware that something's happening. In fact, you might even be aware that it hurts. You just don't care.
A singular bad side effect of it is that it can cause hallucinations that persist after the drug has supposedly worn off.
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https://medicalxpress.com/news/2022-10-ketamine-depression-mechanism-antidepressant-revealed.html
Researchers from Inserm, CNRS, Sorbonne University and clinicians from the AP-HP and at Paris Brain Institute identified one of the mechanisms explaining the ketamine effect as an antidepressant. Ketamine, usually used as an anesthetic, was administered to patients with severe resistant depression.
This treatment led patients to present an increased ability to overcome their negative beliefs about themselves and the world when researchers presented them positive information. These results, published in JAMA Psychiatry, open new therapeutic avenues for the management of antidepressant-resistant mood disorders.
Depression is the most common psychiatric disorder: it is estimated that 5 to 15% of the French population will experience a major depressive episode during their lifetime. All age groups and all social backgrounds are affected.
The disease is characterized by sadness and loss of hedonic feelings that positive events do not improve. Depressed patients progressively develop negative beliefs about themselves, the world, and the future, that may develop into suicidal thoughts. These negative beliefs remain even when the patient receives positive information.
About one-third of people with depression do not respond to the most prescribed antidepressants, leading to a diagnosis of treatment-resistant depression (TRD). For these people, finding new and effective therapies is a priority.
Ketamine, a commonly used anesthetic, has been shown to influence resistant depression. While conventional antidepressant treatments take time to be efficient (on average three weeks), ketamine has a rapid antidepressant effect, only a few hours after administration. The mechanisms associated with this fast-acting antidepressant effect are still unknown.
In the suite of the study, TRD patients received three administrations of ketamine at a subanesthetic dose (0.5 mg/kg over 40 minutes) in one week.
For the sake of comparisons, 0.5mg/kg is a pretty good dose that will provide systemic analgesia without inducing unconsciousness. I always found it to be a useful adjuvant to an epidural when the epidural wasn't quite good enough. I'd usually combine it with about 0.5ug/kg of fentanyl. To induce anesthesia, a dose of about 2 mg/kg is enough. For kids who are not going to be cooperative with starting an IV or getting a mask held on their face, 5 mg/kg
in a "dart"intramuscularly is sufficient to make the rugrat compliant with being moved and transported to the OR.Ketamine, in lower doses, is called a "dissociative anesthetic." In other words, it sort of disconnects your lower brain from your cortex, so that you might be aware that something's happening. In fact, you might even be aware that it hurts. You just don't care.
A singular bad side effect of it is that it can cause hallucinations that persist after the drug has supposedly worn off.
@George-K
So is not giving a damn about the pain the same as relieving depression?I’m confused about the dosage here.
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@George-K
So is not giving a damn about the pain the same as relieving depression?I’m confused about the dosage here.
@Ivorythumper said in Ketamine:
@George-K
So is not giving a damn about the pain the same as relieving depression?Sounds like that's possible, yes. It wouldn't make sense to use this for chronic depression, but sometimes people have very strong acute depression, and for a little while, harming themselves and others is absolutely on the table. Who knows, ketamine might be able to get them to clear the hump and get back to a place that still might not be great, but at least they can think more clearly.
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@George-K
So is not giving a damn about the pain the same as relieving depression?I’m confused about the dosage here.
@Ivorythumper said in Ketamine:
@George-K
So is not giving a damn about the pain the same as relieving depression?I’m confused about the dosage here.
Giving the dose listed in the article during a c-section - 0.5 mg/kg is a good analgesic dose. I have no idea what effect it has on depression, particularly because it's a one-of, and I don't know how these people felt a week later. But, it's a small enough dose to be acutely useful, and chronically insignificant (as a one-of, as I said). That dose, given quickly - as opposed to via infusion over 40 minutes, repeated - though the same dose, probably has different pharmacodynamics. For example, I can give you 200 mg of propofol over an hour, and nothing will happen, though you might get a bit drowsy. If I give it in 30 seconds, you'll stop breathing.
