Ketamine is known for its pain-reducing and sedative effects. In this Healthline article, Mindpath Health’s Julian Lagoy, MD, discusses how the medication is used to treat anxiety as well as its potential side effects.

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Ketamine was originally developed in the 1950s and used in the 1960s as a general anesthetic for medical procedures due to its pain-reducing and sedative effects. In recent years, though, researchers have started investigating the potential benefits of ketamine for treating certain mental health conditions, including anxiety, depression, and post-traumatic stress disorder (PTSD).

While there are a variety of medications used to treat anxiety, research suggests around 50% of people undergoing treatment for generalized anxiety disorder (GAD) are treatment-resistant. That means they don’t experience any improvement after a course of anti-anxiety medication.

The FDA has only approved a particular form of ketamine for treatment-resistant depression, not anxiety. However, doctors may still prescribe ketamine “off-label” to treat anxiety. This is known as ketamine therapy, and the research on its potential benefits has been steadily growing.

How it works

According to Khaled Bowarshi, MD, a psychiatrist, ketamine works by quickly increasing the activity of glutamate in the brain.

Glutamate is one of the brain’s chemical messengers, and it plays an important role in mood regulation, as well as memory and learning.

Glutamate also supports neuroplasticity, or your brain’s ability to adapt and change with every new experience you have. By increasing neuroplasticity, researchers believe ketamine may help “re-wire” your brain, disrupting problematic or harmful thought patterns and allowing you to form new pathways. Those new pathways allow you to create more positive thoughts, which can help to relieve anxiety symptoms.

Ketamine vs. other medications

Traditional anti-anxiety medications start by boosting other brain chemicals, like serotonin, before targeting glutamate.

What sets ketamine apart is that it immediately activates glutamate. This can translate to faster results, according to Kai Lewis, LMFT. While it can take two to six weeks for anti-anxiety medications to work, Lewis notes ketamine can help to relieve anxiety in as little as two hours

Ketamine treatment types

Ketamine can be taken in multiple ways:

  • Intravenous (IV) ketamine infusions: A slow, constant IV drip of ketamine is delivered directly into your bloodstream. This can only be done in a hospital or clinic setting.
  • Intramuscular (IM) shots: Shots are injected into a large muscle, such as your thigh or arm, in a hospital or clinic setting.
  • Sublingual tablets: This form of ketamine is prescribed for at-home use as a stand-alone treatment or for maintenance in between IV or IM treatments. You put a tablet under your tongue and allow it to dissolve slowly. It takes longer for your body to absorb this type of ketamine, so it’s generally considered to be less effective than other forms.
  • Nasal spray: Sprovato (esketamine) can only be administered at a hospital or doctor’s office because someone will need to monitor any side effects. You’ll use the spray once or twice weekly for the first 8 weeks, and then only once every week or 2 in the maintenance phase.

Are there any side effects?

Ketamine therapy involves relatively low doses of ketamine, and the side effects are typically minimal and mild.

That said, Julian Lagoy, MD, a psychiatrist with Mindpath Health, says ketamine is not usually recommended for those who are pregnant or breastfeeding or those who have a diagnosis of schizophrenia.

You’ll also want to talk with your healthcare professional about potential risks if you have:

  • unmanaged high blood pressure
  • a history of substance use disorder (ketamine has the potential to cause physical and psychological dependence)
  • a history of psychosis
  • heart disease
  • a history of increased intracranial pressure

Even if none of those apply to you, ketamine can cause the following side effects:

  • nausea and/or vomiting
  • lightheadedness
  • dissociation, or an out-of-body experience that involves feeling disconnected from your thoughts, identity, and feelings
  • sleepiness
  • increased blood pressure and/or heart rate
  • visual changes, like double vision or blurry vision
  • perceptual changes, like feeling as if time is slowing down or speeding up

Ketamine can also occasionally contribute to increased anxiety. That’s another reason why it’s important to work with a qualified health professional. They’ll be able to monitor your symptoms and provide support for dealing with any negative side effects.

Read the full Healthline article with sources.

Julian Lagoy, M.D.

San Jose, CA

Julian Lagoy, M.D. is a board-certified psychiatrist. He received his bachelor’s degree in philosophy from the University of Notre Dame and his medical degree from St. George’s University. Dr. Lagoy completed his psychiatry residency at Virginia Tech Carilion School of Medicine. Dr. Lagoy has published in multiple medical journals and has presented his research at the American Psychiatric Association National ... Read Full Bio »

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