Dr. Mersad Alimoradi 26 Jan 2023

Over 21 million people worldwide suffer from schizophrenia, a chronic mental condition.

Most schizophrenia therapies depend on antipsychotic medications that alter dopamine or serotonin levels in the brain. However, these drugs often cause strong side effects, which lead to patients stopping their treatment. Moreover, most available schizophrenia medications do not improve life-restricting symptoms other than hallucinations and delusions. 

KarXT is a new schizophrenia drug that works in a completely novel way and does not directly target the dopamine or serotonin pathways in the brain like other available schizophrenia medications.

Studies showed it is safe, well-tolerated, and reduces the symptoms of schizophrenia, including social isolation, cognitive impairment, and memory problems. It was also not associated with problematic side effects commonly reported with other antipsychotic drugs.

These observations provide a new hope and treatment option for people living with this psychotic disorder.

Continue reading to learn more about the newest promising schizophrenia therapy. 

Schizophrenia Facts

Below are some quick facts about schizophrenia.

What is Schizophrenia?

Schizophrenia is a severe mental disorder that causes a range of psychological symptoms. It affects around 3 in every 1,000 people worldwide. 

This mental health condition can result in highly disordered behavior and thinking. A person with schizophrenia may not always be able to tell what is real from what is not.

People often confuse schizophrenia with multiple personality disorder. Individuals with schizophrenia do not have split personality disorder. Instead, they experience ideas or thoughts that are not realistic or true. 

Schizophrenia symptoms

Schizophrenia can cause a variety of symptoms that affect a person’s thinking, behavior, mood, or perception of reality. 

Symptoms of schizophrenia may include the following:

  • Hallucinations (hearing or seeing things that do not exist outside the person’s mind)
  • Delusions (unrealistic thoughts or beliefs)
  • Highly disorganized or abnormal thoughts and actions
  • Inability to function normally
  • Loss of interest in everyday activities
  • Neglecting personal hygiene

Schizophrenia in teenagers may cause the following symptoms:

  • Withdrawal from family and friends
  • Struggling or performing poorly in school
  • Losing motivation
  • Sleeping troubles
  • Irritability or depression

What causes schizophrenia?

The exact cause of schizophrenia remains unknown. Scientists believe that a combination of genetics, environmental factors, and brain chemistry contributes to the development of this disorder.

It has not been established that schizophrenia runs in families. However, researchers do not believe that a single gene may be responsible.

Some studies suggest that two neurotransmitters in the brain (dopamine and glutamate) may be partly responsible for the onset of schizophrenia.

Is Schizophrenia Curable?

Individuals with schizophrenia require lifelong treatment for their condition. Although most patients can recover, many experience relapses later (their symptoms occasionally return).

Therefore, schizophrenia may go away in some cases, although not permanently. Treatment with medication, psychological therapy, and community support can help manage this mental condition and reduce its impact on quality of life.

What Is the Newest Schizophrenia Medication?

So far, antipsychotic drugs are the most commonly prescribed medications for the treatment of schizophrenia. Antipsychotics may help control schizophrenia symptoms by regulating the brain’s dopamine or serotonin (neurotransmitter) levels. 

However, these medications do not work for everyone and may cause serious side effects, such as confusion, agitation, sexual problems, sedation, high blood pressure, weight gain, and constipation. 

More recently, Karuna Therapeutics, a U.S.-based biopharmaceutical company, developed a new combination drug for schizophrenia called KarXT (xanomeline-trospium)

What Is KarXT (xanomeline-trospium)?

KarXT is the first potential new schizophrenia treatment developed in over 50 years. It is an investigational combination therapy that has a novel mechanism of action.

KarXT is a combination drug; it combines two medications called xanomeline and trospium.

Muscarinic receptors are part of the cholinergic neurotransmitter system. This system is heavily responsible for controlling many body functions, such as memory, learning, digestion, movement, and blood pressure.

As a muscarinic agonist, xanomeline can activate these receptors to enhance cognition and lessen psychotic symptoms such as hallucinations, delusions, disturbed thoughts, and behavior.

However, muscarinic agonists have produced undesirable side effects because they also stimulate receptors outside the central nervous system (CNS). That is why the development of schizophrenia therapy targeting muscarinic receptors has been unsuccessful until recently.

Meanwhile, trospium is a muscarinic antagonist. It does the opposite of what xanomeline does. Trospium blocks muscarinic receptors in the body (outside the central nervous system) without affecting those in the brain. 

The dual action of this new schizophrenia therapy allows it to stimulate muscarinic receptors in the CNS selectively without causing the undesirable side effects seen with previous developmental drugs. 

Scientific Evidence Supporting KarXT

Scientists at Karuna pharmaceuticals predicted that combining xanomeline with trospium would reduce the problematic side effects caused by other drugs. 

Several clinical trials have shown promise.

A study to assess the safety and efficacy of KarXT in adults with schizophrenia showed that the drug was safe and well tolerated by patients. Moreover, KarXT reduced undesirable side effects by 50% compared to xanomeline alone. 

Most side effects with KarXT were mild and transient and included the following:

  • Vomiting (for one day)
  • Dry mouth (for 13 days)

The Phase 2 clinical study revealed that KarXT significantly reduces psychosis symptoms in patients with schizophrenia. 

The results from another Phase 2 clinical study showed that the new schizophrenia investigational therapy significantly improves cognition (thinking) in people with schizophrenia.

Positive outcomes from the Phase 3 EMERGENT-2 Trial of KarXT in Schizophrenia Patients were reported by the drug manufacturer (Karuna) in August 2022. The findings are as follows:

  • KarXT significantly reduces schizophrenia symptoms, such as hallucinations and delusions.
  • The new drug significantly improves negative symptoms of schizophrenia, such as impaired thinking, lack of motivation, and social isolation. These improvements are often not achieved by the current schizophrenia drugs.
  • KarXT is not associated with bothersome side effects that commonly occur with other schizophrenia medications, such as weight gain, sedation (sleepiness), and abnormal body movements.


Despite the available schizophrenia therapies, many patients do not respond well to the medications or stop taking them because of the side effects.

KarXT is the first investigational schizophrenia medication in over 50 years to show remarkable results in a Phase 3 clinical trial.

Current treatments for schizophrenia may be effective in reducing specific symptoms, such as hallucinations and delusions. However, they do not improve other negative symptoms that affect the patient’s quality of life, such as memory impairment, cognitive problems, and social withdrawal.

KarXT has the potential to tackle schizophrenia symptoms more comprehensively without causing serious side effects, providing new hope for a better, healthier, and more functional life for people living with psychotic disorders.

By the middle of 2023, Karuna Pharmaceuticals representatives anticipate submitting a New Drug Application to the US Food and Drug Administration as a treatment for schizophrenia for KarXT.

To search for the best Psychiatry doctors worldwide, please use the Mya Care search engine.

To search for the best doctors and healthcare providers worldwide, please use the Mya Care search engine.

About the Author:
Dr. Mersad is a medical doctor, author, and editor based in Germany. He's managed to publish several research papers early in his career. He is passionate about spreading medical knowledge. Thus, he spends a big portion of his time writing educational articles for everyone to learn.


Disclaimer: Please note that Mya Care does not provide medical advice, diagnosis, or treatment. The information provided is not intended to replace the care or advice of a qualified health care professional. The views expressed are personal views of the author and do not necessarily reflect the opinion of Mya Care. Always consult your doctor for all diagnoses, treatments, and cures for any diseases or conditions, as well as before changing your health care regimen. Do not reproduce, copy, reformat, publish, distribute, upload, post, transmit, transfer in any manner or sell any of the materials in this blog without prior written permission from