What Makes OSMOLEX® ER (amantadine) Different?
Osmolex® ER delivers amantadine consistently throughout the day with the Osmodex drug delivery system.1,2
PK profile of Osmolex® ER relative to immediate release amantadine



- PK data do not provide evidence of clinical safety or efficacy.
- There are no head-to-head studies in patients with PD comparing the safety and efficacy of OSMOLEX™ to that of amantadine IR.
These data come from a single-center, laboratory-blinded, randomized, 2-treatment, 2-period, 2-sequence, multiple oral dose crossover study was conducted in 24 healthy volunteers to compare 258-mg amantadine oral syrup (immediate release) twice daily.2
The efficacy of OSMOLEX® ER has been established based on bioavailability studies that compared OSMOLEX® ER to immediate-release amantadine.1,2
The pharmacokinetics of OSMOLEX® ER across 2 different dosage strengths were shown to be dose proportional.1,2
DOSING AND ADMINISTRATION
Multiple dosing options
Every patient is unique, so multiple dosing options allow you to tailor treatment to each individual patient’s needs.


Actual tablet size relative to a penny.
The recommended initial dose of OSMOLEX® ER is 129 mg taken orally once-a-day in the morning.1

OSMOLEX® ER is not interchangeable
with other amantadine immediate-
or extended-release products1

In patients with moderate or severe renal impairment, the dosage interval of Osmolex® ER is extended so the medication is given at the same dose but less frequently. Please see the prescribing information for specific instructions. Osmolex® ER is contraindicated in patients with end-stage renal disease.1

OSMOLEX® ER can be taken with or
without food. OSMOLEX® ER should be
swallowed whole. Do not crush, chew,
or divide the tablet1. Concomitant use of alcohol when using OSMOLEX ER is not recommended.
Quick Reference Dosing: OSMOLEX® ER Amantadine HCl Equivalence1

Tablets shown actual size.
NOTE: The USP Salt Policy (May 2013) requires the name and strength of the active ingredient in a drug product to be expressed in terms of the active moiety rather than the salt strength equivalent.3 Osmolex® ER is dosed as the weight of amantadine (base) whereas immediate-release amantadine is dosed as the weight of the amantadine hydrochloride salt.
Incidence of Adverse Reactions From Pooled Studies of Immediate-Release Amantadine1
Incidence Rate | Adverse Reaction |
5% to 10% | Nausea, dizziness/lightheadedness, insomnia |
1% to 5% | Depression, anxiety and irritability, hallucinations, confusion, anorexia, dry mouth, constipation, ataxia, livedo reticularis, peripheral edema, orthostatic hypotension, headache, somnolence, nervousness, dream abnormality, agitation, dry nose, diarrhea, fatigue |
0.1% to 1% | Congestive heart failure, psychosis, urinary retention, dyspnea, skin rash, vomiting, weakness, slurred speech, euphoria, thinking abnormality, amnesia, hyperkinesia, hypertension, decreased libido, visual disturbance, punctate subepithelial or other corneal opacity, corneal edema, decreased visual acuity, sensitivity to light, optic nerve palsy |
Less than 0.1% | Convulsion, leukopenia, neutropenia, eczematoid dermatitis, oculogyric episodes, suicidal attempt, suicide, suicidal ideation |