OSMOLEX® ER is a once-daily prescription medication used to treat adults with Parkinson’s disease and drug-induced extrapyramidal reactions.1

Person icon

What is Parkinson’s disease (PD)?2

  • PD is a neurological disorder characterized by bradykinesia (slow movement), stiffness, and tremor that typically occurs at rest and may cause other non-movement symptoms
  • Symptoms include tremor or shaking, rigidity or stiffness, extreme slowness of intentional movement, and impaired balance
  • Onset of PD usually occurs after age 60 but can occur earlier
Extrapyramidal reaction icon

What are drug-induced extrapyramidal
reactions (EPR)?3,4

  • EPR are movement disorders that may occur after the administration of certain medications such as antipsychotics
  • EPR may include excessive involuntary muscle contractions (dystonia), symptoms that resemble Parkinson’s Disease (parkinsonism) or uncontrollable movements (tardive dyskinesia)
  • Symptoms can begin immediately (hours or days) after administration of certain drugs or may be delayed (months or longer)
  • These symptoms can cause distress or discomfort for patients and may be stigmatizing
OSMOLEX delivery system icon

How does the extended release delivery system work?

This delivery system involves an immediate-release outer layer of amantadine that dissolves 30 to 60 minutes after the pill is swallowed. The tablet shell then absorbs water, which pushes more amantadine out of the tablet through a laser-drilled hole at a steady rate.

This results in a consistent delivery of amantadine.1,6

The Osmodex
delivery system

This delivery system allows for once-daily dosing with OSMOLEX® ER. When taken in the morning, amantadine plasma
levels are higher during the day, without the need for a second mid-day dose.6

Osmotic pressure delivers amantadine at a controlled release rate throughout the day

Image labeling the drug delivery of an OSMOLEX® ER (amantadine) extended-release tablet Image labeling the drug delivery of an OSMOLEX® ER (amantadine) extended-release tablet
  • Image showing that the color coating and outer layer of amantadine dissolves
    The color coating and outer layer of
    amantadine dissolve
  • Image showing that the tablet shell is semipermeable, which lets water in without letting amantadine out
    The semipermiable tablet shell allows
    water in without letting amantadine out
  • Image showing how amantadine is released through the laser-drilled hole
    Amantadine release through the laser-drilled
    hole is driven by the osmotic pressure
*The biologically inert components of the tablet remain intact during gastrointestinal transit and are eliminated
in the stool as a tablet shell.


  1. OSMOLEX® ER. Prescribing information. Adamas Pharmaceuticals, Inc. 2021.
  2. Parkinson’s Disease. MassGeneral Institute for Neurodegenerative Disease. http://mghmind.org/disease-research/parkinsons-disease. Accessed April 18, 2019.
  3. Extrapyramidal Symptoms – statPearls.
  4. Blanchet P, Kivenko V. Drug-induced parkinsonism: diagnosis and management. Journal of Parkinsonism and Restless Legs Syndrome. 2016;6:83-91.
  5. Parkinson’s foundation. Amantadine. https://www.parkinson.org/Understanding-Parkinsons/Treatment/Prescription-Medications/Amantadine-Symmetrel. Accessed November 4, 2019.
  6. DeVries T, Dentiste A, Handiwala L, Jacobs D. Bioavailability and pharmacokinetics of once-daily amantadine extended-release tablets in healthy volunteers: results from three randomized, crossover, open-label phase 1 studies. Neurol Ther. 2019. DOI: 10.1007/s40120-019-0144-1.