Parkinson's Disease Treatment - Overview

GENERAL PRINCIPLES

  • Motor symptoms are treated by replacing dopamine. Like the oil can helping the Tin Man in The Wizard of Oz, dopamine helps make movements quicker and more fluid.
  • Medications improve daily symptoms but do not slow the progression of disease over time.
  • Medications are taken daily on a routine schedule to control symptoms.
  • Nausea is the most common side effect of dopamine therapy.
  • PD meds should NOT be stopped abruptly, as doing so can cause a life-threatening condition. Please consult with your provider on how to properly wean off a medication if it becomes necessary.
  • Non-motor symptoms typically do not respond to dopamine and require other treatment strategies.

KEY DEFINITIONS

ON time

  • Times when the medications are working well, and PD motor symptoms are well-controlled

OFF time 

  • Times when the medications are not working, and the PD motor symptoms are poorly controlled

Wearing OFF 

  • Medication loses its effect before the next dose is due, resulting in an OFF time

Unpredictable OFF

  • Occurs randomly and is not related to timing of the dose of medication

Morning OFF

  • Severe OFF symptoms are present upon waking, due to an extended time since last dose, and before the morning dose takes effect

Dose failure

  • When a dose is taken and does not provide control of movement symptoms, usually due to gastrointestinal issues

Dyskinesia

  • An abnormal, excessive, involuntary movement caused by PD medication
  • Squirmy, wiggling, or even dance-like movements that can occur anywhere in the body

MAINTINENCE MEDICATION

Levodopa 

  • This is the most potent medication for controlling PD motor symptoms.
  • Levodopa goes into the brain and becomes dopamine.
  • Levodopa must be given with carbidopa, which blocks the breakdown of levodopa in the body and allows it to cross the blood-brain barrier and be converted to dopamine.
  • There are various forms of carbidopa/levodopa:
    • Sinemet
    • Sinemet CR
    • Stalevo
    • Rytary
  • The effect of the dose typically lasts 4-6 hours.
  • The medication is taken three times during the most active part of the day.
  • If wearing off occurs, the frequency is increased, or a levodopa-extending drug is prescribed.

Levodopa extenders 

  • These medications block the breakdown of dopamine in the brain, allowing the levodopa to last longer and help prevent wearing off.
  • Classes
    • COMT inhibitors
      • Entacapone
      • Opicapone
    • MAO inhibitors
      • Selegiline
      • Rasagiline

Dopamine agonists

  • These medications mimic the activity of dopamine but are not as potent as levodopa.
  • They can be used initially for treatment or in combination with levodopa.
  • Dopamine agonists are:
    • Pramipexole
    • Ropinirole
    • Rotigotine patch
  • Rare but serious side effects include:
    • Impulse control disorder
    • Sleep attacks
  • Dopamine agonists are used with caution in the elderly because of potential for additional side effects, such as:
    • Confusion
    • Memory loss
    • Hallucinations

MEDICATIONS FOR SPECIAL CIRCUMSTANCES

Rescue medications

  • These are on-demand therapies used to treat wearing off, unpredictable off, and early morning off episodes.
  • The effects typically take 15-20 minutes to kick in and usually last about 90 minutes.
  • Rescue medications are only taken as needed.
  • Rescue medications are:
    • Apomorphine injectable and sublingual film
      • Side effects include nausea and drops in blood pressure.
    • Levodopa inhaler
      • Side effects are the same as levodopa tablets, plus cough due to inhaling a very fine powder.

Medications for dyskinesia

  • Abnormal, excessive involuntary movements are caused by the PD medications.
  • Dyskinesia medications are
    • Gocovri
    • Amantadine
  • These medications may cause hallucinations.