Some of the different types of dopamine agonists are ropinirole, pramipexole, and apomorphine. These medications are often prescribed for patients who have Parkinson's disease, and while these drugs cannot cure the disease, they may help delay symptoms. Dopamine agonists are usually reserved for people who have recently been diagnosed with Parkinson's disease, however they may sometimes be used in the later stages of the disease, along with other medicines.
The body naturally produces dopamine, a neurotransmitter that works with the brain to control movements. It also plays a key role in a person's ability to sense pain or pleasure, and to experience emotional responses to stimuli. People who are diagnosed with Parkinson's disease have abnormally low levels of this neurotransmitter.
Dopamine agonists bind to the dopamine receptors in the central nervous system and stimulate these receptors. Essentially, they do the job that dopamine is supposed to perform. These drugs mimic the effects of dopamine in order to reduce symptoms like muscle stiffness or spasms, and poor muscle control. Sometimes, a doctor may also prescribe dopamine agonists to a patient with restless legs syndrome (RLS), a condition in which the patient's legs spasm uncontrollably.
Two types of dopamine agonists, ropinirole and pramipexole, are taken orally. These drugs are intended to be taken on a regular schedule, with or without food. Pramipexole may be available in an extended-release tablet.
In contrast, apomorphine is a fast-acting type of dopamine agonist. A patient may take either ropinirole or pramipexole regularly, but they may also be prescribed apomorphine for use in emergencies. These emergencies include incidents in which the patient is immobile because his muscles do not respond. For example, a patient may be unable to stand up from a seated position. In these circumstances, a caregiver would inject the apomorphine into the skin to “unfreeze” the muscles.
The possible side effects of these medicines depend on which specific dopamine agonist the patient is using. Some common side effects may include constipation, drowsiness, and blurred vision. A runny nose, dry mouth, and headaches may also occur. Patients have also reported indigestion, forgetfulness, and mild dizziness.
More serious side effects require urgent medical care, including flu symptoms, shortness of breath, and muscle pain. Rapid heartbeats, hallucinations, and uncontrollable muscle movements have also been reported. Some patients may fall asleep while performing normal daytime activities, while others have reported decreased coordination, confusion, and nausea. Fainting, severe dizziness, and chest pains may also occur.
Before using any type of dopamine agonist, patients must disclose their other medical conditions, medications, and supplements. Women who are pregnant or breastfeeding should discuss the risks with their doctors. These drugs may be contraindicated for use by those with heart problems, sleep disorders, or high blood pressure. Dopamine agonists may interact with other drugs, including blood thinners, estrogens, and benzodiazepines.