Amantadine is a synthetic antiviral agent that also has strong antiparkinsonian properties. It is sold in the United States under the brand name Symmetrel, and is also available under
its generic name.
Amantadine is used to treat a group of side effects (called parkinsonian side effects) that include tremors, difficulty walking, and slack muscle tone. These side effects may occur in patients who are taking antipsychotic medications used to treat mental disorders such as schizophrenia. An unrelated use of amantadine is in the treatment of viral infections of some strains of influenza A.