An infusion or injection solution of Levodopa containing at least 5 mg/mL of Levodopa together with at least 0.5 mg/mL of at least one inhibitor of a Levodopa-metabolising enzyme is disclosed. The solution further contains a buffer, a physiologically acceptable sugar, such as glucose, a physiologically acceptable acid, such as hydrochloric acid, and optionally a stabilizer, and has a pH of lower than or equal to 6. There are also described a disposable syringe containing an infusion or injection solution of Levodopa, together with a Levodopa-metabolising enzyme, and an infusion pump cassette containing an infusion or injection solution of Levodopa together with a Levodopa-metabolising enzyme.
