Biperiden HCl is primarily used in the treatment of Parkinson's disease to manage symptoms such as tremors, rigidity, and bradykinesia. It works by blocking acetylcholine receptors, helping to restore the balance between dopamine and acetylcholine in the brain. Additionally, it is effective in controlling drug-induced extrapyramidal symptoms, such as those caused by antipsychotic medications. Biperiden HCl is also utilized in the management of dystonia and other movement disorders. Its anticholinergic properties make it useful in reducing excessive muscle activity and improving motor control in patients with these conditions.