Osmolex ER

Osmolex ER (amantadine hydrochloride) is an oral treatment for Parkinson’s disease. It was developed by Osmotica Pharmaceuticals and later acquired by Supernus Pharmaceuticals.

The U.S. Food and Drug Administration (FDA) approved it in February 2018 to treat both Parkinson’s and therapy-induced movement and muscle-control problems that typify this disease and can be side effects of common medications.

How Osmolex ER works

Parkinson’s disease is a progressive neurological disorder marked by tremors, stiffness, and slowness of movement. These symptoms are due to decreased dopamine levels in the brain, a chemical important in facilitating movement. Patients with Parkinson’s are treated with medication such as levodopa to replace dopamine.

However, taking levodopa for long periods of time causes patients to develop unpredictable, fluctuating responses to the medication, such as uncontrolled writhing movements known as dyskinesia.

Amantadine, originally developed as an antiviral medication, helps lessen the severity of dyskinesia, although how it does so is not fully understood.

Osmolex ER contains amantadine in Osmotica’s patented Osmodex drug delivery system. The capsule contains an outer layer that immediately releases the medication upon the patient taking the pill and an inner core that slowly releases the medication over long periods of time. (“ER” refers to “extended release.”) This allows Osmolex ER to be taken just once a day, easing complicated medication routines.

Osmolex ER in clinical trials

Osmolex ER was tested in two Phase 3 clinical trials, ALLAY-LID I (NCT02153645) and ALLAY-LID II (NCT02153632). These trials aimed to determine the efficacy and safety of Osmolex ER in patients with Parkinson’s with levodopa-induced dyskinesia. Patients were given either 240 mg or 320 mg of oral Osmolex ER or a placebo for either three months (in the ALLAY-LID I trial) or for six months (in the ALLAY-LID II trial).

Both trials were carried out at various locations in the U.S., Germany, France, and Spain. Both trials also ended a year earlier than expected completion dates, although no information was available on the reasons behind this.

Additional information

Osmolex ER is available in single oral tablets in doses of 129 mg, 193 mg, and 258 mg and meant to be taken in the morning.

The most common side effects reported are nausea, dizziness or lightheadedness, and difficulty sleeping.

Osmolex ER should be used with caution in those with a history of psychiatric illnesses, as it may worsen symptoms of depression or psychosis.

Osmolex ER should not be stopped abruptly, as there is a risk of patients developing serious, life-threatening reactions.

Osmolex ER is also FDA-approved for treating abnormal muscle movements such as muscle contractions, restlessness, irregular, jerky movements, and tremors. These symptoms are collectively known as extrapyramidal symptoms and can occur as a side effect of taking certain medications.

Page updated: Nov. 29, 2021


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