There is no cure for Parkinson’s disease. Medications are usually recommended and can substantially reduce a patient’s symptoms. Most medications are aimed at increasing the levels or reducing the breakdown of dopamine in the brain. However, it is not possible to take dopamine in pill form because the chemical is broken down before it can reach the brain.  

Most patients receive a combination of the drugs levodopa and carbidopa to treat the symptoms of Parkinson’s disease. Neurons inside the body convert levodopa to dopamine, and carbidopa helps to ensure that this process does not happen until the levodopa reaches the brain. Carbidopa also helps reduce side effects that are associated with levodopa, such as nausea and vomiting. Other side effects of levodopa include dyskinesia (uncontrollable movements), sudden sleep onset, hallucinations and psychosis.  

Most patients who take this medication gain some benefit from it, according to the National Institute of Neurological Disorders and Stroke (NINDS). Usually, these drugs have the most significant impact on rigidity and slowness of movement. They are also effective in reducing tremors. However, they may have little or no effect on other symptoms, such as postural instability or nonmotor-related symptoms. They also do not repair or replace damaged nerve cells in the brain, nor do they stop progression of the disease. 

The benefits of levodopa therapy are usually experienced soon after beginning the medication, although the dosage may be gradually increased over time in order to be most effective. Levodopa can dramatically increase the quality of life for people with Parkinson’s disease. However, it is not a cure for Parkinson’s disease and cannot slow the progression of the disease. Eventually, the effectiveness of levodopa therapy may decrease, in which case patients usually experience a gradual worsening of symptoms (called the “wearing off effect”) or periodic attacks of more severe symptoms (called the “on-off effect”).  

Other drugs may be used to treat the symptoms of Parkinson’s disease or increase the effectiveness of levodopa. These may include:

• Dopamine agonists. These drugs treat Parkinson’s disease by mimicking the effects of dopamine on target cells. They are sometimes used in conjunction with levodopa. Although they are generally considered safe, the side effects from this type of medication can include sleep disorders, hallucinations, confusion and nightmares. They have also been linked to compulsive behavior (e.g., gambling, hypersexuality, excessive shopping) in some patients.
  
  
• COMT inhibitors and MAO-B inhibitors. These drugs inhibit the breakdown of dopamine caused by the enzymes catechol-O-methyltransferase (COMT) and monoamine oxidase B (MAO-B). They are often used to extend the effectiveness of levodopa. The most common side effect from these medications is diarrhea. People who are taking certain other drugs (e.g., the antidepressant fluoxetine or the pain medication mepiridine) should consult their physician before taking certain MAO-B inhibitors as they may have harmful interactions.
  
  
• Anticholinergics. These drugs are primarily used to treat tremors and muscle rigidity. They work by reducing the effects of the neurotransmitter acetylcholine. It is thought that excess levels of acetylcholine increase neuron activity in the brain and that, by reducing these levels, anticholinergics may be effective in controlling tremors and muscle rigidity. However, anticholinergics are only effective in roughly half of the patients who use them, according to the NINDS. Even for people who respond well to anticholinergics, the medication usually offers limited benefits for a short period of time. Side effects may include dry mouth, constipation, urinary retention, hallucinations and delirium.
  
  
• Amantadine. This drug may be used to treat the symptoms of Parkinson’s disease, as well as some of the side effects of levodopa, such as dyskinesia. Amantadine is an antiviral drug that is sometimes used to treat certain types of influenza. It is not fully understood how the drug works to control symptoms of Parkinson’s disease, although it is thought to increase the effects of dopamine. Side effects may include insomnia, mottled skin and hallucinations.

If medications fail to alleviate symptoms, patients with advanced Parkinson’s disease may be advised to undergo surgery. One of the most common procedures is a form of surgery called deep brain stimulation. In this procedure, electrodes are placed in the brain and connected to a small electrical device (called a pulse generator) that is surgically implanted in the chest wall. The pulse generator delivers electrical stimulation to specific parts of the brain in order to reduce the patient’s symptoms. The device can be controlled by the patient and reprogrammed by a physician as needed. 

It is important to note that not all patients are good candidates for surgery. Deep brain stimulation has been shown to be more effective on younger patients with Parkinson’s disease and is generally not suitable for patients who are in poor overall health. However, some older patients in good health have benefited from deep brain stimulation.

Another form of surgery, known as a pallidotomy or thalamotomy (depending on the area of the brain targeted), involves the destruction of parts of the brain that are associated with the symptoms of Parkinson’s disease. During this procedure, surgeons use radio frequency energy to heat and destroy the globus pallidus (pallidotomy) or the thalamus (thalamotomy). Abnormal activity in these two small areas in the brain is believed to contribute to movement problems in people with Parkinson’s disease.

Because of the risks with radiofrequency destruction of the globus pallidus or thalamus, deep brain stimulation is usually a preferred treatment method over pallidotomy and thalamotomy for patients with advanced Parkinson’s disease.

Surgery may improve many of the symptoms of Parkinson’s disease. However, patients may find that they still have to rely on medication to effectively control symptoms. They may also still have to take medication to treat symptoms that are not affected by surgery, such as nonmotor-related symptoms. 

Physical therapy and occupational therapy can help patients learn new ways to cope with their symptoms. Physical therapy includes a mixture of exercise, massage and other treatments to maintain strength and flexibility. A physical therapist is likely to teach the patient exercises that can be performed at home to strengthen and retrain muscles. This helps patients improve balance and reduce fatigue. Occupational therapy is similar to physical therapy, but it focuses on improving patients’ fine motor skills so they can better accomplish daily activities, such as dressing and bathing.

Patients are encouraged to engage in complementary or supportive therapies, such as eating a well-balanced diet and exercising regularly. Eating a diet that is high in fiber and consuming plenty of fluids can help reduce constipation, which can be associated with Parkinson’s disease. Additionally, patients who remain active may better cope with the disabling nature of the disease.

Finally, some patients and their caregivers may find that support groups or individual counseling are helpful when coping with Parkinson’s disease. This type of therapy may be a valuable outlet for both the patient and the patient’s caregiver to discuss feelings of frustration or depression.