OSMOLEX® ER (amantadine) Is Indicated for Both Parkinson's Disease and Drug-Induced Extrapyramidal Reactions1
Parkinson's Disease (PD)2
PD is primarily a movement disorder.
Motor system symptoms of
Resting limb tremors
Stiffness and rigidity
Drug-Induced Extrapyramidal Reactions (EPR)3,4
Commonly referred to as drug induced movement disorders, EPR are among the more common adverse drug reactions that patients experience from dopamine receptor blocking drugs such as anti-psychotics. EPR is a broad term comprising several different drug induced movement disorders including parkinsonism, dystonic reactions, akathisia, and tardive dyskinesia. The amantadine IR approval for EPR was based on studies evaluating treatment of anti-psychotic-induced parkinsonism.
Drug-induced EPR due to antipsychotic drug (APD) use:
One of the more commonly observed movement disorders induced by APDs.5
- Uncontrolled movement appearing within a few weeks of initation or dosage increase of an APD4
- 50% of cases display additional signs of tardive dyskenisia or akathisia4
Involuntary movement that may be irreversible, occurring months to years after receiving APD therapy.5
- Occurs in about 20%-30% of patients who receive long-term APD treatment6
Involuntary movements that may appear in all muscle groups, but are observed mainly in the head and neck area.7
- 95% of cases appear within 96 hours of starting treatment with APDs, or after a large increase in the dose7
*OSMOLEX® ER was approved through the 505b(2) pathway where clinical trials evaluating the safety and efficacy in drug-induced EPR were not required for submission. OSMOLEX® ER reflects similar labeling as amantadine IR and is indicated for the treatment of drug-induced extrapyramidal reactions in adult patients.
- OSMOLEX® ER. Prescribing information. Adamas Pharmaceuticals, LLC; 2021.
- Parkinson’s Disease. MassGeneral Institute for Neurodegenerative Disease. http://mghmind.org/disease-research/parkinsons-disease. Accessed April 18, 2019.
- Extrapyramidal Symptoms – statPearls.
- Blanchet P, Kivenko V. Drug-induced parkinsonism: diagnosis and management. Journal of Parkinsonism and Restless Legs Syndrome. 2016;6:83-91.
- Ward KM, Citrome L. Antipsychotic-related movement disorders: drug-induced parkinsonism vs. tardive dyskinesia-key differences in pathophysiology and clinical management. Neurol Ther. 2018;7(2):233-248. DOI: 10.1007/s40120-018-0105-0.
- Carbon M, Hsieh CH, Kane JM, Correll CU. Tardive dyskinesia prevalence in the period of second-generation antipsychotic use: a meta-analysis. J Clin Psychiatry. 2017;78(3):e264-e278. DOI: 10.4088/JCP.16r10832.
- Harten PN, Hoek HW, Kahn RS: Acute dystonia induced by drug treatment. BMJ. 1999;319:623-626. DOI: 10.1136/bmj.319.7210.623.