Naloxone Dosage-Reply

In Reply. —We have used naloxone hydrochloride experimentally in patients with parkinsonism treated with levodopa for a long period. The drug was given in a single IV injection over three to four minutes, once daily for three successive days. It exerts its effects on central neuronal mechanisms previously perturbed by pharmacologic manipulations, as in persons treated with narcotics or, as in our trial, with levodopa. In our experience, significant results were obtained only after administering relatively high doses of naloxone hydrochloride (8 mg), and we reported the side effects observed. In fact, naloxone administration at this dosage did not cause any side effects in normal subjects, as previously indicated by other authors,1who also used higher dosages of the drug.