NMDA Receptor Antagonists

The NMDA receptor antagonists are a type or group classification of anesthetics. They work to inhibit, or antagonize (and hence the interesting nickname) the action of the N Methyl D aspartate receptor (NMDAR). These drugs are considered to be anesthetics for both humans and animals, and are capable of producing a state known as dissociative anesthesia. Incidentally, several of the medications that fall into this classification are also used as recreational drugs since they also have hallucinogenic and euphoriant properties. These drugs are also used because they are very effective, especially in the emergency room. Patients without a known medical history are often given something like Ketamine (a popular NMDA receptor antagonist) since it will depress breathing and circulation less than most other types of anesthetics.

NMDA Receptor Antagonists Drugs

Some typical NMDA receptors antagonists drugs include:

  • Ketamine
  • Methadone
  • Propoxyphene
  • Dextromethorphan
  • Phencyclidine
  • Methoxetamine
  • Nitrous Oxide

NMDA Receptor Antagonists Uses

Several types of NMDA receptors antagonists are used in the emergency room. They tend to depress the breathing and circulation less than most other categories of pain relievers. Burn victims tend to also see a number of positive effects when being treated with such medications.

NMDA receptors antagonists are also widely used as recreational drugs. Even when used in smaller doses, they tend to have at least mild stimulant effects. Taking higher doses can result in hallucinations and other types of dissociation. Obviously, the particular effects and their strength will vary according to the dosage and type of drug used.

There is also much promise that these types of medications may be useful in treating conditions of excitotoxicity. This can include issues like:

  • Benzodiazepine withdrawal
  • Traumatic brain injury
  • Stroke
  • Neurodegenerative diseases (Alzheimer's, Parkinson's, Huntington's)

NMDA Receptor Antagonists Side Effects

Perhaps the most noted side effect of NMDA receptors antagonists are those which result from recreational drug use. This includes primarily hallucination and leading to a dissociative state, from which people will quickly recover.

When used in the operating room or through a medical professional, such drugs can have other side effects. This can include:

  • catalepsy
  • amnesia
  • analgesia

Although this may or may not be perceived as a side effect, taking such drugs over time can lead to tolerance (since they are metabolized by the liver).

There are also some scientists and medical professionals who think depressed NMDA receptor function may occur over time, especially as we age. This can then become associated with a wide range of negative symptoms like:

  • confusion
  • difficulty concentrating
  • agitation
  • mood alterations
  • nightmares
  • learning and memory deficits

NMDA Receptor Antagonists Interactions

You will want to avoid using additional central nervous system medications when taking these NMDA receptors antagonists, since they can have the effect of making you overly drowsy. Another type of drug interaction occurs when combined with monoamine oxidase inhibitors. Taken together, this can lead to serotonin syndrome, which is a potentially life threatening condition that can happen rapidly.

There are also some known food interactions. For example, when using dextromethorphan, it is recommended to avoid any grapefruit or grapefruit juice. This is also true for several other citrus fruits like limes.

Main NMDA Receptor Antagonists Drugs

Namenda Namenda XR Ketalar

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