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Osmolex ER Side Effects

Generic name: amantadine

Medically reviewed by Drugs.com. Last updated on Feb 5, 2024.

Note: This document provides detailed information about Osmolex ER Side Effects associated with amantadine. Some dosage forms listed on this page may not apply specifically to the brand name Osmolex ER.

Applies to amantadine: oral capsule, oral capsule extended release, oral capsule liquid filled, oral solution, oral syrup, oral tablet, oral tablet extended release.

Serious side effects of Osmolex ER

Along with its needed effects, amantadine (the active ingredient contained in Osmolex ER) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking amantadine:

More common

  • bladder pain
  • bloody or cloudy urine
  • blurred vision
  • confusion
  • difficult, burning, or painful urination
  • dizziness or lightheadedness
  • fainting
  • falls
  • frequent urge to urinate
  • lower back or side pain
  • seeing, hearing, or feeling things that are not there
  • swelling of the hands, feet, or lower legs

Less common

  • inability to move the eyes
  • increased blinking or spasms of the eyelid
  • muscle spasm
  • sticking out of the tongue
  • trouble breathing, speaking, or swallowing
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual facial expressions

Rare

  • chills
  • decreased vision or any change in vision
  • difficulty in coordination
  • fever
  • increased blood pressure
  • increase in body movements
  • irritation and swelling of the eye
  • loss of memory
  • mental depression
  • seizures
  • severe mood or mental changes
  • skin rash
  • slurred speech
  • sore throat
  • thoughts of suicide or attempts at suicide

Other side effects of Osmolex ER

Some side effects of amantadine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • agitation
  • anxiety
  • difficulty concentrating
  • dry mouth
  • headache
  • irritability
  • loss of appetite
  • nausea
  • nervousness
  • nightmares
  • purplish red, net-like, or blotchy spots on the skin
  • trouble with sleeping

Less common

  • blindness
  • blurred vision
  • constipation
  • decrease in sexual desire
  • decreased vision
  • diarrhea
  • drowsiness
  • dry eyes
  • dryness of the mouth, nose, and throat
  • false sense of well-being
  • joint swelling
  • unusual tiredness or weakness
  • vomiting

For healthcare professionals

Applies to amantadine: compounding powder, oral capsule, oral capsule extended release, oral liquid, oral tablet, oral tablet extended release.

General

The more commonly reported adverse reactions have included nausea, dizziness/lightheadedness, and insomnia.[Ref]

Nervous system

Psychiatric

Gastrointestinal

Cardiovascular

Ocular

Other

Deaths have been reported from overdose with the lowest reported acute lethal dose as 1 gram. Drug overdose has resulted in cardiac, respiratory, renal, or CNS toxicity. Deaths have been reported in patients with renal impairment and attributed to drug accumulation.[Ref]

Respiratory

Hematologic

Dermatologic

Hypersensitivity

Genitourinary

Renal

Hepatic

Musculoskeletal

References

1. (2002) "Product Information. Symmetrel (amantadine)." DuPont Pharmaceuticals

2. (2018) "Product Information. Gocovri (amantadine)." Adamas Pharmaceuticals Inc.

3. (2018) "Product Information. Amantadine Hydrochloride (amantadine)." Sandoz Inc

4. Smith EJ (2008) "Amantadine-induced psychosis in a young healthy patient." Am J Psychiatry, 165, p. 1613

5. Michalski LS, Hantsch Bardsley C, Holt DR, Milner JE, Hou SH (2009) "Altered mental status in a transplant patient. Amantadine toxicity." Kidney Int, 75, p. 243-4

6. (2009) "Antiviral drugs for influenza." Med Lett Drugs Ther, 51, p. 89-92

7. Kataoka H, Ueno S (2011) "Dropped head associated with amantadine in Parkinson disease." Clin Neuropharmacol, 34, p. 48-9

8. Beal E (2011) "Parkinson disease: Amantadine administration is associated with impulse control disorders in PD." Nat Rev Neurol, 7, p. 62

9. Salgado JC, Gutknecht DR (2006) "A reticular rash." Am J Med, 119, p. 577-8

10. Alonso Navarro H, Sanz-Aiz A, Izquierdo L, Jimenez Jimenez FJ (2009) "Syndrome of Inappropriate Antidiuretic Hormone Secretion Possibly Associated With Amantadine Therapy in Parkinson Disease." Clin Neuropharmacol, 32, p. 167-168

Frequently asked questions

Further information

Osmolex ER side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.