Dopamine is a complex and key neurotransmitter responsible for many of our daily physical and mental functions.
Changes in levels of this brain chemical can alter our behavior, movement, mood, memory, and many other reactions.
Dopamine agonists (DA) are medications that work by imitating the actions of dopamine when levels are low. These medications improve condition-related symptoms by fooling the brain into thinking dopamine is available.
Dopamine agonists are prescription medications that can be used alone or in combination with other medications to treat a variety of conditions that are a result of dopamine loss.
The D1 group includes D1 and D5 receptors, and the D2 group includes D2, 3, and 4.
Each is found in different areas throughout our body and responsible for important actions from how we move to how we learn. Lack of dopamine in our cells affects our bodies in many negative ways.
Dopamine agonists bind to the D1 and D2 group of dopamine receptors in the brain, copying the effects of the neurotransmitter in order to improve disorders that happen from low levels.
They’re mostly prescribed for their effects on movement related and hormone related disorders.
They can improve other related troubles such as sleep disorders, pain, and emotional concerns that co-occur with certain dopamine-linked conditions.
These medications are not as strong as levodopa-type medications that are used for Parkinson’s disease, but they don’t have the more severe uncontrolled movement related side effects, called dyskinesia, associated with long-term use of levodopa.
Newer dopamine agonists are helpful for the early treatment of Parkinson’s disease.
It’s important to understand that influencing dopamine receptor actions (up or down) can generate good and bad effects. These medications do have some serious risks including problems with impulse control and addiction.
There are two main categories of DA medications, ergoline and non-ergoline.
The first generation are ergoline type and are used less often today since they have some serious heart- and lung-related risks linked with their use. This is mainly because the older medications attach to any available dopamine receptors in the body and are not selective.
Examples of ergoline DA
Bromocriptine (Parlodel). Approved to treat Parkinson’s disease and dopamine-related hormonal conditions like hyperprolactinemia and related conditions, Bromocriptine is a prescription drug, available as a tablet or capsule, that comes in both generic and brand versions. It’s rarely used today.
Cabergoline. This prescription medication is available as a tablet used to treat hyperprolactinemia, a condition in which high levels of the hormone prolactin are produced by the pituitary gland. Increased prolactin levels can interfere with women’s menstrual cycle, ovulation, and milk production. In men, it can cause reproductive and sexual problems.
Examples of non-ergoline DA
These newer medications bind to more specific dopamine receptors and have fewer heart and lung side effects.
Apomorphine (Apokyn). A short acting injectable medication used to provide quick relief from sudden Parkinson’s symptoms, Apomorphine takes effect within 10 minutes and the effects last about an hour. There are some very serious side effects and drug interactions with this medication. Talk to your doctor or pharmacist about precautions you need to be aware of when taking this medication.
Pramipexole (Mirapex). This is a prescription medication available in tablet form in brand and generic versions. The short and long acting forms are used to treat symptoms of Parkinson’s disease (PD), a chronic degenerative condition in which dopamine cells slowly die causing movement and mood related disorders. Pramipexole helps improve movement-related symptoms and is especially useful in patients younger than 60 to slow symptom progress. The short acting version is also used to treat symptoms of restless legs syndrome.
Ropinirole (Requip). This is a prescription medication available in both brand and generic versions in tablet form. It’s available as both short and long acting types and is used to treat symptoms of PD and restless legs syndrome, a condition in which there’s an urge to constantly move the legs, even during rest. This can disturb sleep and cause daytime tiredness.
Rotigotine (Neupro). A once-a-day prescription medication that’s available as a transdermal patch in several strengths, Rotigotine is used to treat symptoms of Parkinson’s disease and restless legs syndrome.
Side effects from DA medications can vary depending on the medication (ergoline versus non-ergoline), dose, how long the medication is used, and individual traits.
If you’re experiencing side effects which are bothersome, don’t stop taking the medication on your own. Talk to your doctor about treatment options available to help improve your condition. This includes non-medication options too.
Side effects might be mild and go away after a few days or they may be important enough to need either a dose change or to stop the medication. DA medications can cause withdrawal symptoms or worsening of the condition if they’re suddenly stopped.
This is not a full list of side effects. Ask your pharmacist or doctor about specific concerns related to your medication.
Side effects for dopamine agonists include:
- increased heart rate
- heart valve problems, heart failure
- dry mouth
- nausea, vomiting, constipation
- runny nose
- increased blood pressure
- low blood pressure
- trouble with memory or concentration
- movement-related problems (dyskinesia)
- sudden sleepiness
- paranoia, agitation
- swelling of legs or arms
There are some serious risks with dopamine agonist medications, especially the older generation drugs. Risks vary based on the medication, dosage, and individual reactions.
If you have a history of heart or blood pressure problems, kidney or liver disease, and psychosis or other mental health problems, your doctor may discuss benefits versus risks of DA medications for your condition.
These are some risks associated with DA medications. This isn’t a complete list of possible risks. Discuss any specific concerns you have about your medication with your doctor.
- Heart attack. Symptoms such as chest pain, shortness of breath, nausea, and sweating.
- Stroke. Symptoms like numbness of an arm or leg, slurred speech, paralysis, loss of balance, and confusion.
- Withdrawal syndrome. Symptoms have been
reportedfrom cutting down or suddenly stopping dopamine agonist doses. It can cause a serious condition called malignant syndrome (symptoms include high fever, rigidity, loss of consciousness, and kidney failure). It can also cause severe anxiety, depression, and sleep and mood problems. It’s important not to suddenly stop or lower the dose of these medications. Your doctor will slowly ease the dosing down if you’re having side effects or other problems with the medication.
- Increase in restless legs syndrome. Early morning symptoms and rebound effects are possible.
- Compulsive behavior. Compulsive gambling, binge eating, shopping, sex, and other behaviors may start or worsen. Talk to your doctor if you notice behavior changes in you or a loved one. Ask your doctor about this risk and what you need to know.
- Hallucinations. Different types of sensory hallucinations (visual, sound, smell, and taste) that can be intense and disturbing can occur.
- Low blood pressure. Symptoms such as fainting and dizziness when you stand up from sitting or lying down (orthostatic hypotension).
- Sudden sleepiness. This symptom can be dangerous. Be careful with activities that need alertness like driving until you become used to the medication. Avoid alcohol or other substances that can increase drowsiness.
- Problems with posture. Some DA medications like pramipexole can cause abnormalities in your body positioning (leaning, bending).
- Fibrosis. Scarring of tissue in the lungs, heart, or stomach along with symptoms including shortness of breath, cough, chest pain, swelling of legs, weight loss, and tiredness can occur.
- Increase in psychosis. These medications may worsen mental health conditions and symptoms.
- Muscle deterioration (rhabdomyolysis). Symptoms can include dark urine, muscle weakness, soreness, and fever.
When to see your doctor
Contact your doctor immediately if you have any of the following symptoms:
- compulsive behavior that puts you or someone else at risk
- strong hallucinations that interfere with daily life function
- worsening of symptoms
- heart problems (increased heart rate, chest pain, swelling of legs or arms)
If you have an allergic reaction to a dopamine agonist medication (swelling of tongue, difficulty breathing, rash) call 911 right away and seek medical attention.
Dopamine agonists are a broad category of medications that mimic the actions of dopamine in the body to relieve symptoms related to low levels of dopamine. They’re most often used to treat Parkinson’s disease and restless legs syndrome but are also prescribed for other conditions.
Side effects from dopamine agonists can be serious and include compulsive or risky behavior. Worsening of disease symptoms with long-term use is possible.
Your doctor will discuss risks versus benefits of dopamine agonist medications and monitor you while you’re taking the medication for side effects.
Until you’re used to the medication, be careful driving or doing other activities that need you to be alert. Don’t stand up too quickly to avoid balance problems, dizziness, and sudden fainting.
Ask your pharmacist about drug interactions with prescription, over-the-counter medications, supplements, and DA medications.
It’s important to discuss any concerns you have about your condition and medications with your doctor on a regular basis. Don’t stop taking any medication suddenly without talking to your doctor first.