OSMOLEX® ER is a once-daily prescription medication used to treat adults with Parkinson’s disease or 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
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.


OSMOLEX ER is a prescription medicine used to treat:

  • Parkinson’s disease
  • Drug-induced extrapyramidal reactions in adult patients

It is not known if OSMOLEX ER is safe and effective in children.



  • have kidney problems. Do not take OSMOLEX ER if you have severe kidney problems
  • have unexpected sleepiness, take medicine to help you sleep or that makes you drowsy
  • have mental problems, such as suicidal thoughts, depression, or hallucinations
  • have unusual urges, including gambling, increased sex drive, compulsive eating, or compulsive shopping
  • You should not drink alcohol during treatment with Osmolex due to increased chances of serious side effects
  • are pregnant or plan to become pregnant or are breastfeeding or plan to breastfeed. OSMOLEX ER may harm your unborn baby and can pass into your breastmilk

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Especially tell your doctor if you take sodium bicarbonate, a medicine that contains sodium bicarbonate, or are planning to receive the flu vaccine. You may receive the flu vaccine shot but should not get a live flu vaccine (nasal spray) while taking OSMOLEX ER


  • Do not drive, operate heavy machinery, or do other dangerous activities until you know how OSMOLEX ER affects you
  • You should not drink alcohol while taking OSMOLEX ER because it can increase your chances of serious side effects
  • Do not stop taking OSMOLEX ER or change your dose before talking with your doctor. Tell your doctor if you have symptoms of withdrawal such as fever, confusion, or severe muscle stiffness


OSMOLEX ER may cause serious side effects, including:

  • falling asleep during normal activities, such as driving, talking, or eating, while taking OSMOLEX ER. You may fall asleep without being drowsy or warning. The risk is greater if you take OSMOLEX ER with other medicines that cause drowsiness or drink alcohol. Tell your doctor right away if this happens
  • suicidal thoughts or actions and depression. Tell your doctor right away if you have significant changes in your mood, behaviors, or thoughts, including thoughts about hurting yourself or ending your life
  • hallucinations (seeing, or hearing things that are not real) while you are taking OSMOLEX ER or if you suddenly stop taking OSMOLEX ER
  • feeling dizzy, faint, or light-headed, especially when you stand up too quickly, when you first start OSMOLEX ER, or if your dose has been increased. Tell your doctor if you become dizzy, light-headed, or faint when standing up
  • unusual urges, including gambling, sexual, spending money, and binge eating, and the inability to control these urges. If you notice or your family notices that you are developing any unusual behaviors, talk to your doctor

The most common side effects of OSMOLEX ER include nausea, dizziness, lightheadedness, and trouble sleeping.

These are not all the possible side effects of OSMOLEX ER. Call your doctor for medical advice about side effects. You may report side effects to FDA.

Visit www.fda.gov/medwatch or call at 1-800-FDA-1088.

Please see full Patient Prescribing Information.