Dopamine Agonists

What is a dopamine agonist?

Dopamine agonists are drugs that activate certain types of cells in your brain. They’re a key type of drug for treating movement disorders, especially Parkinson’s disease. Simply put, they activate dopamine receptors.

Cells throughout your nervous system have receptors, which are like locks, on their surfaces. Neurotransmitters are chemicals that your brain uses for communication and control of certain processes. They’re a lot like keys. They have very specific shapes and can “unlock” cells, activating them.

Dopamine (pronounced “DOE-pah-meen”) is one of the most important neurotransmitters in your brain. It’s a key part of how you learn and experience feelings of reward and pleasure. Cells in parts of your brain that control muscle movements also need dopamine to work correctly.

Dopamine agonists are useful because dopamine-dependent cells react to them the same way they would to dopamine. They aren’t dopamine, but your cells can’t tell the difference.

What does dopamine do, and what conditions do dopamine agonists treat?

A lack of dopamine can cause major disruptions in how your brain works. Your body also needs dopamine to control processes related to your:

• Heart.
• Kidneys.
• Pancreas.
• Pituitary gland.
• Endocrine system.
• Digestive system.
• Reproductive system (both female and male).

When you don’t have enough dopamine, it can cause many different conditions. Dopamine agonists are approved for or used off-label to treat the following:

• Parkinson’s disease and related parkinsonism-type conditions and symptoms.
• Restless legs syndrome.
• High prolactin levels (hyperprolactinemia).
• Neuroleptic malignant syndrome (a rare, deadly complication of certain antipsychotic drugs).
• Dangerously high blood pressure (hypertensive crisis).
• Type 2 diabetes.
• Amenorrhea (no period) and oligomenorrhea (fewer than six or eight periods in a year) for people who have periods.

What drugs are dopamine agonists?

There are several dopamine agonists, but not all have the same uses. Some are mainly for brain-related conditions like Parkinson’s disease. Others are mainly to treat conditions outside your brain.

The earliest dopamine agonist drugs came from ergot, a type of rye fungus. While there are fewer of these in use, some still see use for certain conditions.

Ergot-based dopamine agonists

• Bromocriptine (Cycloset®, Parlodel®).
• Cabergoline. The name brand of this drug (Dostinex) is no longer available in the U.S. But generic versions remain in use.

Non-ergot-based dopamine agonists

• Amantadine (Gocovri®, Osmolex®).
• Apomorphine (Apokyn®, Kynmobi®).
• Fenoldopam (Corlopam®).
• Pramipexole (Mirapex®).
• Ropinirole. The name brand of this drug (Requip) is no longer available in the U.S. But generic versions remain in use.
• Rotigotine (Neupro®).

How common are prescriptions for dopamine agonists?

Dopamine agonist prescriptions are common. Millions of people in the U.S. have a prescription for them. Parkinson’s disease-related prescriptions are the most common.

What are the potential benefits of dopamine agonists?

Dopamine agonists have several benefits and advantages, including:

• Effectiveness. Research confirms that dopamine agonists are very effective in treating many conditions.
• Range of conditions they can treat. Dopamine agonists have U.S. government approval to treat many different conditions, ranging from brain-related movement disorders to endocrine problems that cause menstrual cycle disruptions.
• Combination potential with other medications. Dopamine agonists can reduce the needed dosage for other medications. An example is adding a dopamine agonist alongside levodopa for treating Parkinson’s disease. Using both at the same time makes lower doses of levodopa just as effective as higher doses would be on their own.
• Life-saving potential. Dopamine agonists can treat and reverse neuroleptic malignant syndrome, a rare — but potentially deadly — complication that can happen when taking antipsychotic medications.

What are the risks or complications of taking dopamine agonists?

While they’re very effective, there are some possible risks or complications from taking dopamine agonists. These side effects are usually more common as dosage increases. They include:

• Constipation.
• Dizziness.
• Headaches.
• Indigestion.
• Irregular heart rhythms (arrhythmia).
• Nausea and vomiting.
• Orthostatic hypotension (feeling lightheaded or passing out when standing up too quickly).
• Uncontrolled chorea-like muscle movements.

Long-term use of dopamine agonists can also lead to mental health- and behavior-related changes. Some examples include:

• Confusion.
• Depression.
• Impulse control issues.
• Mania.
• Psychosis-like symptoms (delusions and hallucinations).
• Sleep attacks and daytime sleepiness (especially with pramipexole and ropinirole).

Impulse control issues

Dopamine agonists mimic the effects of dopamine. That can affect your behavior, especially your self-control abilities. That can lead to compulsive behaviors, meaning you can’t manage them. Some examples include:

• Extreme insatiable hunger (polyphagia).
• Engagement with hobby activities.
• Gambling.
• Hypersexuality.
• Shopping.

Dopamine agonist withdrawal syndrome

Dopamine agonist withdrawal syndrome (DAWS) is a potential complication of suddenly reducing the dose of or stopping dopamine agonist medications. It affects between 15% and 20% of people who suddenly switch to a reduced dose or stop their medication altogether.

Researchers are still investigating this effect because it isn’t well understood. However, research shows strong evidence that it happens. The symptoms include:

• Anxiety and panic attacks.
• Excessive sweating (diaphoresis).
• Agitation.
• Fatigue.
• Pain.
• Nausea.
• Orthostatic hypotension.

Research also shows three risk factors increase your risk of developing DAWS:

• Higher doses of dopamine agonists (this depends on the medication you take).
• Impulse control disorder that happened in connection with taking a dopamine agonist.
• Previously receiving deep brain stimulation (a possible treatment for Parkinson’s disease).

Having one of those three factors carries a 30% risk of developing DAWS. Having two of them carries a 70% risk. Having all three carries a 92% risk.

Are there any reasons why I can’t or shouldn’t take dopamine agonists?

There are several reasons you might not be able to take dopamine agonists. Healthcare providers call these “contraindications.” These can include:

• Pregnancy and breastfeeding (chestfeeding). People who are pregnant or breastfeeding (chestfeeding) shouldn’t take dopamine agonists because they can interfere with lactation.
• High blood pressure (hypertension). Some dopamine agonists can increase your blood pressure, which can be an issue if your blood pressure is already high.
• Risk of fibrosis-type conditions. Conditions that cause fibrotic tissue to form, such as pulmonary fibrosis, are more likely to happen when you take ergot-based dopamine agonists. That’s one reason only two of these are still in use in the U.S. (the others were removed or withdrawn from use).
• Kidney or liver disease. Your kidneys and liver help process medications and remove waste products from your body. Having kidney or liver disease, or failure of either organ, can make it harder for your body to process dopamine agonists.
• Taking certain medications. You shouldn’t take dopamine agonists if you already take monoamine oxidase inhibitor (MAOI) drugs. You’ll need at least two weeks off MAOIs before starting a dopamine agonist.
• History of psychosis-related conditions or symptoms. The risk of developing psychosis symptoms is much higher in people who already have a history of these mental health concerns.

How long can I stay on dopamine agonists?

You can typically stay on dopamine agonists for years. But the risk of certain side effects increases the longer you’re on them.

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

Whether you can work or drive if you’re taking dopamine agonists depends on several factors, including your reason for taking a dopamine agonist, the drug you take and more. Your healthcare provider is the best person to tell you if it’s safe to work or drive while taking these medications.

What’s the difference between dopamine vs. dopamine agonists?

There are a few key factors in the use of synthetic dopamine vs. dopamine agonists:

• Side effects. Dopamine can cause side effects throughout your body. Depending on your health history and current situation, some of these side effects might not be helpful (or could even be harmful).
• The blood-brain barrier. Dopamine can’t cross the blood-brain barrier, a protective filter-like layer around the blood vessels inside your brain. Your brain gets dopamine because other molecules convert into dopamine because of chemical processes in your brain. Dopamine agonists can enter your brain directly, making them available without needing conversion.
• How long you can take them. The main treatment for Parkinson’s disease later in life is a drug called levodopa. After levodopa crosses the blood-brain barrier, your body converts it to dopamine. But you need higher doses over time for it to remain effective, and it causes severe side effects at higher doses. Dopamine agonists can treat Parkinson's earlier in life, allowing you to wait until later to begin taking levodopa. You can also take both at the same time, which can get you a greater effect even with a lower levodopa dose.

How do dopamine agonists make you feel?

Dopamine agonists can have different effects on how you feel, and how they affect you can vary from person to person. Some people may not feel any different, while others may feel physical effects like dizziness or nausea.

Other people may not feel anything at first but may start to feel different after long-term use of these medications. Your healthcare provider is the best person to explain the effects you might feel and what you can or should do if you notice any changes in how you feel.

Do dopamine agonists cause euphoria?

Some people may experience feelings like mania or euphoria when taking certain dopamine agonists, but this isn’t common.

Are dopamine agonists used for depression?

Dopamine agonists may help depression, but they don’t have official approval in the U.S. for treating it. Research shows that combining dopamine agonists with certain antidepressants may have a stronger effect on treating depression than antidepressants alone. But more research is necessary to confirm this or rule it out.

A note from Cleveland Clinic

Dopamine agonists represent an important part of managing chronic conditions and preserving the ability to live independently. They’re some of the most important tools for treating Parkinson’s disease, especially early in the course of the condition. They can also help delay dose increases for other Parkinson’s drugs like levodopa, extending how long you can take those drugs. They can treat many other conditions, too, making them some of the most important prescription medications currently in use.