Parkinson’s disease is a disease that affects the brain cells responsible for producing dopamine, leading to trembling, stiffness and problems with coordination and balance.

Treatment for Parkinson’s disease is aimed at restoring dopamine balance and improving motor function and other manifestations of the disease. Doctors may prescribe levodopa, dopamine agonists, anticholinergic drugs, COMT inhibitors, and MAO-B inhibitors to relieve symptoms.

This article provides an overview of the most common medications used to treat Parkinson’s disease.

What drugs help in the fight against Parkinson’s disease?

Medical professionals use a variety of medications to treat this disease.

Levodopa is one of the key drugs that compensates for the lack of dopamine. Also used are dopamine agonists, which mimic its action, COMT inhibitors, which increase the effectiveness of levodopa, and MAO-B inhibitors, which prevent the destruction of dopamine.

In addition to the main treatments for Parkinson’s disease, there are other medications that help manage certain symptoms, including:

Anticholinergic drugs to control shivering
Amantadine to eliminate uncontrollable movements
Exelon (rivastigmine) for the treatment of mild to moderate dementia associated with Parkinson’s disease
Nurianz (istradefylline) to combat “fade out” episodes in which Parkinson’s patients experience muscle stiffness and loss of muscle control.

Levodopa and Carbidopa

Carbidopa/levodopa is a combination drug sold under the brand name Sinemet.

Levodopa acts as a prodrug, i.e. is a precursor to dopamine. Its action is to replace dopamine lost in Parkinson’s disease. Carbidopa is given along with levodopa to prevent it from breaking down before it crosses the blood-brain barrier.

Levodopa is considered the most effective drug for Parkinson’s disease. People who take levodopa for a long time sometimes experience movement complications known as dyskinesias. This side effect can be managed by adjusting your medication regimen.

Dopamine agonists

Dopamine agonists are a class of medications that act similarly to dopamine at dopamine receptors. They are usually prescribed as initial therapy for young patients.

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As the disease progresses, many patients will require a combination of treatments, including dopamine agonists. However, not all drugs in this class are suitable for treating Parkinson’s disease.

Here are some examples of dopamine agonists used to treat this disorder:

Mirapex (pramipexole)
Ropinirole
Neupro (rotigotine)
Apokine (apomorphine)
Although generally well tolerated, the following side effects may occur:

Compulsive behavior
Sleep problems
Confusion
Swelling and discoloration of the legs
Movement disorders
Dizziness
Sudden discontinuation of dopamine agonists may cause dopamine withdrawal syndrome, accompanied by symptoms such as apathy.

Anticholinergic drugs

Anticholinergics are primarily used to reduce tremor. They are also effective in combating other symptoms of Parkinson’s disease, such as muscle stiffness, excess salivation, and excessive sweating.

They are often recommended by doctors as first-line treatment for younger patients, but significant side effects make them less suitable for older people (aged 65 years and older) due to the risk of negative reactions. Some of these side effects include:

Dry mouth
Constipation
Urinary retention
Deterioration of vision
Drowsiness
Confusion
Examples of anticholinergic drugs include:

Benztropine
Trihexyphenidyl
Levsin (hyoscyamine)
Anticholinergics can be taken alone or in combination with levodopa or dopamine agonists.

COMT inhibitors

COMT inhibitors are usually taken with levodopa to prolong its action. They are effective in reducing “flat-off” episodes, when symptoms of Parkinson’s disease, such as muscle stiffness and loss of muscle control, return between doses of the drug.

COMT inhibitors work by blocking the metabolism of levodopa by inhibiting the enzyme catechol-o-methyltransferase (COMT).

Possible side effects include:

Uncontrolled movements
Confusion or hallucinations
Nausea or diarrhea
Passing orange urine
Lower blood pressure
Examples of COMT inhibitors include:

Comtan (entacapone)
Tasmar (tolcapon)
Ongentis (opikapon)

MAO-B inhibitors

Selective MAO-B inhibitors help prevent the breakdown of dopamine and increase its activity. They are usually used in combination with carbidopa and levodopa.

These drugs are usually used to treat the «waning off» episodes that can occur when levodopa is taken along with other Parkinson’s disease drugs. Only selegiline and rasagiline can be taken alone as initial therapy for people with mild motor symptoms.

Possible side effects of MAO-B inhibitors may include:

Nausea
Headache
Sleep problems
Vague condition in older people (most often with selegiline)
Examples include:

Zelapar (selegiline) in the form of tablets for oral administration
Azilect (rasagiline)
Xadago (safinamide)
Other drugs
Amantadine is prescribed to eliminate dyskinesia and tremor. It is an N-methyl-D-aspartate (NMDA) inhibitor that blocks dopamine reuptake and increases its release.

Gokowri (amantadine) is a modified, long-acting form of amantadine used with levodopa to improve motor activity.

Nurianz (istradefylline) is sometimes used with carbidopa and levodopa. Its mechanism of action is not fully understood, but it is believed to block adenosine receptors, which makes it effective in treating “fading” episodes.

Exelon (rivastigmine) is used to treat mild to moderate dementia caused by Parkinson’s disease. It interacts with acetylcholinesterase, which plays an important role in memory.

Stalevo (carbidopa, levodopa and entacapone) is a combination of three drugs. Levodopa compensates for the loss of dopamine, carbidopa prevents the premature degradation of levodopa, and entacapone, as a COMT inhibitor, increases its duration of action.

Conclusion

Parkinson’s disease affects the brain cells responsible for producing dopamine, leading to impairments in movement and cognitive function.

Currently, there is a wide arsenal of drugs to combat Parkinson’s disease. These include levodopa, dopamine agonists, anticholinergics, COMT inhibitors, and MAO-B inhibitors.

Levodopa helps replace dopamine deficiency, dopamine agonists mimic its effects, COMT inhibitors prolong the effectiveness of levodopa, and MAO-B inhibitors help prevent its breakdown.

In addition to these main drugs, there are other drugs that can be used to treat Parkinson’s disease, such as amantadine, Exelon, Nurianz and Stalevo.

At Neuro Implant Clinic we strive to improve the quality of life of patients with this disease. With our treatment, we aim to minimize symptoms and make everyday life easier for our patients. Find out more about our procedures by visiting neuroimplantclinic.com, calling +34 656 500 167 or emailing [email protected].