Actually they are the same substance. A chloride ion is introduced to amantadine to become amantadine hydrochloride. This will be helpful to increase the solubility of amantadine. Most drugs are absorbed faster by the body if they are salts, especially hydrochloride salts and sulfate salts

yes

Amantadine is generally well tolerated, but may cause dizziness and nausea. It is classified as pregnancy schedule C. Since amantadine is excreted in breast milk, breastfeeding while taking amantidine is not recommended.

Amantadine

Symmetrel