Effect of Intravenous Amantadine on Gait Freezing in Parkinson's Disease

Randomized Double-blind Placebo-controlled Trial of Intravenous Amantadine on Gait Freezing in Patients With Parkinson's Disease

A double-blinded randomized placebo-controlled trial of intravenous amantadine on gait freezing refractory to oral anti-parkinsonian medications in patients with Parkinson's disease.

• administration of IV amantadine or normal saline for 5 days, 2 times a day while keeping current oral anti-parkinsonian medications unchanged
• follow-up after administration of IV amantadine for 4 weeks
• allocation ratio of amantadine:normal saline is 2:1

Intravenous amantadine is known to be effective for parkinsonian motor symptoms abruptly aggravated and for disabling motor symptoms from severe motor fluctuation and dyskinesia in patients with Parkinson's disease. The study investigators experienced several open label cases who were benefit from intravenous amantadine in their parkinsonian motor symptoms and freezing of gait as well. In addition, there is a pilot open label trial in parkinsonian patients with refractory freezing of gait which showed marked benefit in patients with Parkinson's disease, but not in patients with parkinson-plus syndromes.

This study was aimed to evaluate the efficacy of intravenous amantadine in both levodopa-unresponsive freezing of gait and disabling off state freezing of gait in patients with Parkinson's disease.

Inclusion Criteria:

• the diagnosis of Parkinson's disease according to the United Kingdom Parkinson's Disease Brain Bank criteria
• presence of freezing of gait and the scores of Freezing of Gait Questionnaire 7 or more
• having been treated with oral dopamine replacement therapy for 6 months or more
• score of Korean version of mini-mental status examination is 20 or more

Exclusion Criteria:

• presence of significant cognitive dysfunction, behavioral or psychiatric disorders
• presence of severe cardiac disease
• presence of renal failure, seizure, peptic ulcer disease, liver disease, pheochromocytoma, chronic exhaustive disease, or malignancy
• participation to other clinical trial within 4 weeks
• pregnancy or lactating women
• hypersensitivity to study drugs
• history of intoxication to heavy metals