Dopamine agonists are a form of drug that treats conditions such as Parkinson’s disease. Dopamine agonists imitate dopamine, which is a chemical that is important for various physical and mental functions.
Low levels of dopamine are linked to depression, schizophrenia, and Parkinson’s disease.
In this article, you will learn more about how dopamine agonists work, what diseases they treat, and their side effects.
What are dopamine agonists?
Dopamine agonists are prescription drugs that treat diseases which occur due to dopamine loss. A person may use dopamine agonists alone, or alongside other drugs and treatment methods.
Dopamine is a neurotransmitter. A neurotransmitter is a chemical messenger that passes signals from nerve cells to other cells of the body. Dopamine helps with functions such as movement, memory, mood, learning, and cognition.
If a person does not have enough dopamine, they can develop certain medical conditions.
Dopamine agonists help to take the place of dopamine in a person’s body.
There are various dopamine agonists approved by the United States Food and Drug Administration, including:
- pramipexole (Mirapex)
- ropinirole (Requip)
- apomorphine injection (Apokyn)
- rotigotine (Neupro)
Doctors prescribe different dopamine agonists to treat different symptoms and diseases.
How do dopamine agonists work?
In the body, there are two types of dopamine receptors, which both have different subgroups. Dopamine receptors receive dopamine, creating a signal for a specific function to occur, such as movement. The different types of dopamine receptors are responsible for different mental and physical functions.
The two types of dopamine receptors are D1-like dopamine receptors and D2-like dopamine receptors. The D1-like dopamine receptor group contains the subtypes D1 and D5. The D2-like dopamine receptor group contains D2, D3, and D4 subtypes.
Dopamine agonists bind to the D1-like and D2-like dopamine receptors. By doing so, dopamine agonists activate the dopamine receptors in the same way that dopamine does. This means that dopamine agonists can help to relieve symptoms that occur due to low dopamine levels.
Which diseases do dopamine agonists treat?
Dopamine agonists are used to treat various diseases, such as:
- Parkinson’s disease
- restless leg syndrome
- neuroleptic malignant syndrome, a rare side effect of antipsychotic medication
- hyperprolactinemia, a disease that occurs when a person has too high levels of the hormone prolactin
- type-2 diabetes
- hypertensive emergencies, which occur when a person has severely high blood pressure and organ damage
In the treatment of advanced Parkinson’s disease, doctors prescribed dopamine agonists alongside the drug levodopa (Duopa).
However, according to the World Health Organization, healthcare professionals discovered that a person can take dopamine agonists by themselves to delay motor function impairments.
Dopamine agonists are not as effective as levodopa, but they are less likely to cause erratic, involuntary movements.
Side effects of dopamine agonists
Dopamine agonists can have different side effects depending on the drug used, length of use, and dosage. A person may also be more likely to experience dopamine agonist side effects if they are over 65 years old.
Common side effects of dopamine agonists are:
- nausea and vomiting
- low blood pressure when a person sits up or stands
- irregular heartbeat
Long term use of dopamine agonists can cause side effects such as:
- jerky or writhing movements
- uncontrollable and possibly painful muscle movements
Other side effects of dopamine agonists include:
- falling asleep suddenly
- daytime tiredness
- leg swelling
If a person experiences any side effects while taking dopamine agonists, they should speak with a doctor. Doctors can adjust a person’s dosage, or timing of doses to remove or limit side effects.
Dopamine agonists can also interact with some drugs, foods, or supplements. It is important that a person tells a doctor about any other medication they are taking before starting to take dopamine agonists.
Women need to tell a doctor if they are pregnant or breast-feeding before taking dopamine agonists.
Risks of taking dopamine agonists
Dopamine agonists can cause a person to develop more severe side effects. A person who is concerned about the risks of dopamine agonists should speak with a doctor about their medication.
Serious side effects of dopamine agonists include:
- heart disease
- fibrosis, in which the tissue gets scars or become thicker
- heart failure
- increased chance of developing cancer
Impulse control disorders
A person who takes dopamine agonists may also have a higher chance of developing impulse control disorders. Impulse control disorders can make a person participate in gambling, excessively spend, or have a higher sex drive.
A research from 2018 found that approximately 46% of people taking dopamine agonists to treat Parkinson’s disease developed impulse control disorders over 5 years.
Researchers also found that length of use and increased dosage of dopamine agonists were associated with impulse control disorders. Impulse control disorders gradually disappeared after people stopped taking dopamine agonists.
Symptoms when suddenly stopping taking dopamine agonists
Suddenly stopping taking dopamine agonists can be harmful. A study from 2017 found that up to 19% of people who stop taking dopamine agonists experience some symptoms.
If a person suddenly stops taking dopamine agonist medication, they can develop a serious condition called neuroleptic malignant syndrome.
Neuroleptic malignant syndrome can cause a person to have symptoms such as:
- stiff muscles
- difficulty swallowing
- body shaking
- lack of control over urination or defecation
- changes in mental state
- anxiety that causes a person to be unable to speak
- high heart rate
- high or unexpected changes in blood pressure
- high levels of white blood cells
- raised creatine phosphokinase levels, an enzyme that usually increases if there is damage muscle tissue
You need to make sure that you do not stop taking dopamine agonists suddenly. A doctor can help you safely stop taking dopamine agonists if it is necessary.
If a person experiences severe or worrying symptoms while taking dopamine agonists, they need to talk to a doctor immediately.
Dopamine agonists are a type of drug used to mimic the effects of dopamine. Dopamine is a neurotransmitter which participates in various mental and physical functions. A person can take dopamine agonists to treat a number of different diseases.
A person may experience certain side effects while taking dopamine agonists. Side effects from dopamine agonists range from mild to severe. Dopamine agonists can increase a person’s chances of developing impulse control disorders.
Suddenly stopping taking dopamine agonist medication can cause a person to develop some symptoms. A person should not stop taking dopamine agonists unless under guidance from a doctor.
If a person has any serious or worrying side effects while taking dopamine agonists, they need to talk to a doctor immediately.