Dopamine Antagonists

What is a dopamine antagonist?

Dopamine antagonists are drugs that keep certain types of cells in your brain from activating. They’re a key type of drug for treating certain mental health conditions and symptoms, especially psychosis and schizophrenia. In simple terms, they’re dopamine receptor blockers.

Dopamine (pronounced “DOE-pah-meen”) is a neurotransmitter, a chemical that your brain uses for communication and control of certain processes. Cells throughout your nervous system have receptors, which are like locks, on their surfaces. Neurotransmitters are like keys, and they have very specific shapes. Neurotransmitters fit into receptors so they can “unlock” and activate cells.

Dopamine antagonists fit into dopamine receptors but don’t activate them. Instead, they block receptor activation. Think of them like a placeholder card for a seat at a special event. It isn’t the same thing as a person sitting in the chair, but you still know you can’t sit there.

What conditions do dopamine antagonists treat?

Dopamine antagonists treat different conditions depending on the targeted receptors. Different types of drugs can block dopamine receptors. Many of these affect multiple types of receptors. Some can activate certain receptors while blocking others.

Dopamine antagonist medications generally fall into two classes:

• Antipsychotic drugs.
• Antiemetic drugs (these treat nausea and vomiting).

Many of these drugs can treat both psychosis symptoms and nausea/vomiting. However, not all of them see widespread use for both.

Antipsychotic drugs can treat many conditions, including (but not limited to):

• Schizophrenia (and its related spectrum of disorders, including schizoaffective disorder and schizophreniform disorder).
• Bipolar disorder.
• Delusional disorder.
• Mania.
• Major depressive disorder (with or without psychotic features).
• Severe agitation.
• Borderline personality disorder.
• Substance-induced psychotic disorder.

Antipsychotic drugs that are dopamine antagonists

First-generation (typical) antipsychotics include:

• Chlorpromazine (Thorazine*).
• Fluphenazine (Prolixin*, Permitil*).
• Haloperidol (Haldol®).
• Loxapine (Adusuve®, Loxitane*).
• Molindone (Moban*).
• Perphenazine (Trilafon*).
• Pimozide (Orap*).
• Prochlorperazine (Compazine®*, Compro®).
• Thiothixene (Navane*).
• Thoridazine (Mellaril*).
• Trifluoperazine (Stelazine*).

*The brand name of this medication is no longer available in the U.S., but generic versions still are.

Second-generation (atypical) antipsychotics include:

• Aripiprazole (Abilify®, Aristada®).
• Asenapine (Secuado®, Saphris®).
• Brexpiprazole (Rexulti®).
• Cariprazine (Vraylar®).
• Clozapine (Clozaril®, Versacloz®, Fazaclo*).
• Iloperidone (Fanapt®).
• Lumateperone (Caplyta®).
• Lurasidone (Latuda®).
• Olanzapine (Zyprexa®, Lybalvi®, Symbyax®).
• Quetiapine (Seroquel®).
• Paliperidone (Invega®).
• Pimavanserin (Nuplazid®).
• Risperidone (Perseris®, Risperdal®).
• Ziprasidone (Geodon®).

Antiemetic drugs that are dopamine antagonists

Several drugs that treat nausea and vomiting do so by blocking dopamine receptors. Many of these are also — or mainly — used as antipsychotics (which is why they’re also listed above).

• Amisulpride (Barhemsys®).
• Metoclopramide (Reglan®, Gimoti®).
• Droperidol (Inapsine®).
• Haloperidol (Haldol®).
• Chlorpromazine (Thorazine®).
• Prochlorperazine (Compazine®*, Compro®).
• Olanzapine (Zyprexa®, Lybalvi®, Symbyax®).

*This brand name of this medication is no longer available in the U.S., but generic versions still are.

NOTE: One medication, domperidone, also falls under this class. The U.S. Food and Drug Administration (FDA) banned domperidone in 2004, but may approve use for treating digestive tract conditions in rare cases. People seeking this use must apply for case-by-case consideration.

How common are prescriptions for dopamine antagonists?

Dopamine antagonist medications prescriptions are common. Millions of adults in the U.S. have a prescription for medications of this type.

What are the potential benefits of dopamine antagonists?

Dopamine antagonists are very useful because they slow down the activation of certain kinds of cells. Depending on the class of drug, that can have different benefits.

Antipsychotic drugs

Dopamine antagonists are extremely helpful, or even lifesaving, when used to treat psychosis. Psychosis-related conditions are often difficult to treat with other medications. Without these drugs, many people would need long-term (or even lifelong) around-the-clock mental healthcare.

Psychosis can also be dangerous (both directly and indirectly). People with psychosis may be vulnerable to people who want to take advantage of their condition. Much less commonly, people with psychosis may be a danger to themselves or others. Antipsychotics reduce vulnerability and keep those who take them safer from many forms of harm.

Antiemetic drugs

For most people, feeling nauseated and vomiting (throwing up) is unpleasant or inconvenient. But for some people, it can be dangerous.

One particular example is people who have cancer. Many cancer treatments, especially chemotherapy, can cause nausea that’s so severe to the point it becomes dangerous. Dopamine antagonists are a possible alternative when other drugs don’t work. These drugs are also helpful for stopping nausea and vomiting that are common when general anesthesia wears off after surgery or medical procedures.

What are the risks or complications of taking dopamine antagonists?

The possible risks and complications with dopamine antagonists depend on many factors, especially the medication you take. Your health history and other factors can also play a role.

Some of the possible side effects of dopamine antagonists include:

• Inability to hold still (akathisia).
• Dystonia and tardive dyskinesia.
• Heart rhythm changes (similar to long Q-T syndrome).
• Orthostatic hypotension (low blood pressure when you stand up suddenly that causes dizziness or fainting).
• Neuroleptic malignant syndrome (this is rare but life-threatening).
• Sedation, including feeling tired or sleepy.
• Prolactin hormone level changes, causing missed periods (amenorrhea) and leaky discharge from your breasts when you aren’t breastfeeding/chestfeeding (galactorrhea).
• Can aggravate symptoms of restless leg syndrome.

Your healthcare provider can tell you more about the possible risks and complications that you’re most likely to experience. They can also tell you what you can do to minimize or avoid these.

How long can I stay on dopamine antagonists?

Some dopamine antagonists are medications you only need in certain situations. Antiemetic drugs are an example of this. Other dopamine antagonists, such as antipsychotic medications, you can take for years or indefinitely.

Can I work or drive if I’m taking dopamine antagonists?

Whether you can work or drive while taking a dopamine antagonist can vary. Several of these medications can make you tired or sleepy, so you may be unable to go about your routine like usual while taking them. Your healthcare provider is the best person to tell you whether it’s safe to work or drive while taking these medications, and what to keep in mind.

A note from Cleveland Clinic

Dopamine antagonists play a major role in the treatment of mental health conditions. They also reduce the effects of nausea in certain settings, especially for people receiving chemotherapy for conditions like cancer.

While these drugs commonly cause certain side effects, especially movement-related symptoms, they still help millions of people every day. It’s generally possible to manage their side effects or minimize their effects on your life.