From the Guidelines
Parkinson's disease diagnosis and treatment should be guided by a comprehensive clinical evaluation, with treatment typically beginning with levodopa/carbidopa, and may include dopamine agonists, MAO-B inhibitors, and non-pharmacological approaches to manage symptoms and improve quality of life. The diagnosis of Parkinson's disease (PD) is based on clinical evaluation by a neurologist, looking for cardinal symptoms like tremor, rigidity, bradykinesia (slowness of movement), and postural instability 1. There is no definitive test, but brain imaging, DaTscan, and response to levodopa may support diagnosis. Treatment typically begins with levodopa/carbidopa (Sinemet), starting at 25/100 mg three times daily, which remains the most effective medication by increasing dopamine levels in the brain. For younger patients or those with milder symptoms, dopamine agonists like pramipexole (Mirapex) 0.125-0.5 mg three times daily or ropinirole (Requip) 0.25-1 mg three times daily may be used first to delay levodopa-related complications. MAO-B inhibitors such as selegiline (5-10 mg daily) or rasagiline (1 mg daily) can be used as early monotherapy or as adjuncts. As the disease progresses, treatment becomes more complex, often requiring combinations of medications, adjusted dosing schedules, and management of "wearing-off" periods with COMT inhibitors like entacapone (200 mg with each levodopa dose) 1. Deep brain stimulation surgery may benefit patients with medication-resistant tremor or severe fluctuations. Non-pharmacological approaches including regular exercise, physical therapy, occupational therapy, and speech therapy are essential components of comprehensive care, and optimization of antiparkinsonian treatment can help ameliorate motor symptoms that contribute to dysphagia in PD patients 1. Early referral to a movement disorder specialist is recommended for optimal management of this progressive neurodegenerative condition. Some key points to consider in the diagnosis and treatment of PD include:
- Clinical evaluation by a neurologist is essential for diagnosis
- Levodopa/carbidopa is the most effective medication for managing symptoms
- Dopamine agonists and MAO-B inhibitors can be used as adjuncts or monotherapy
- Non-pharmacological approaches are essential for comprehensive care
- Optimization of antiparkinsonian treatment can help manage dysphagia and other motor symptoms.
From the FDA Drug Label
Parkinson’s disease is a progressive, neurodegenerative disorder of the extrapyramidal nervous system affecting the mobility and control of the skeletal muscular system. Its characteristic features include resting tremor, rigidity, and bradykinetic movements. Current evidence indicates that symptoms of Parkinson's disease are related to depletion of dopamine in the corpus striatum. Administration of dopamine is ineffective in the treatment of Parkinson's disease apparently because it does not cross the blood-brain barrier However, levodopa, the metabolic precursor of dopamine, does cross the blood-brain barrier, and presumably is converted to dopamine in the brain.
The diagnosis of Parkinson's disease (PD) is based on its characteristic features, including:
- Resting tremor
- Rigidity
- Bradykinetic movements The treatment options for PD include:
- Levodopa: a metabolic precursor of dopamine that crosses the blood-brain barrier and is converted to dopamine in the brain
- Carbidopa: an inhibitor of decarboxylation of peripheral levodopa, which increases the availability of levodopa for transport to the brain
- Pramipexole: a dopamine agonist that can be used as monotherapy or in combination with levodopa 2 Note that the provided drug labels do not explicitly discuss diagnosis, but rather focus on the treatment of PD.
From the Research
Diagnosis of Parkinson's Disease
- Parkinson's disease is diagnosed based on history and examination, including prodromal features, characteristic movement difficulty, and psychological or cognitive problems 3
- Examination typically demonstrates bradykinesia with tremor, rigidity, or both 3
- Dopamine transporter single-photon emission computed tomography can improve the accuracy of diagnosis when the presence of parkinsonism is uncertain 3
Treatment Options for Parkinson's Disease
- Treatment is symptomatic, focused on improvement in motor and nonmotor signs and symptoms 3
- Dopamine-based therapies typically help initial motor symptoms 3
- Nonmotor symptoms require nondopaminergic approaches, such as selective serotonin reuptake inhibitors for psychiatric symptoms and cholinesterase inhibitors for cognition 3
- Rehabilitative therapy and exercise complement pharmacologic treatments 3, 4
- Advanced treatments, such as therapy with levodopa-carbidopa enteral suspension or deep brain stimulation, can help individuals with medication-resistant tremor, worsening symptoms, and dyskinesias 3, 4, 5
Pharmacological Treatment
- Dopaminergic pharmacotherapy for PD consists of levodopa and other dopaminergic drugs, such as dopamine agonists and monoamine oxidase B inhibitors 5
- Non-dopaminergic pharmacological approaches, including zonisamide and istradefylline, are also available 5
- Dopamine agonists can be used as monotherapy or in combination with levodopa 6, 7
- Early initiation of combination therapy with levodopa and dopamine agonists may reduce the severity and delay the appearance of complications associated with long-term administration of levodopa 6
Non-Pharmacological Treatment
- Rehabilitative therapy, including physical, occupational, and speech therapy, can help individuals with PD 4
- Exercise, including strenuous aerobic exercise programs, can be neuroprotective and improve motor function 4
- Complementary and alternative medicine substances, such as those used in maintenance therapy, may support and protect the brain microenvironment 4