Abstract
Although many drugs for Parkinson's disease (PD) with different modes of action are employed in clinical settings, the wearing-off phenomenon occurs frequently in the advanced stages of the disease; thus, more therapeutic options are required. Our clinical observations have found that the oral administration of codeine phosphate ameliorated wearing-off in two cases of PD. Case 1 was a woman in her 60s. One day, she had a common cold and took an antitussive, expectorant drug, Aneton, an over-the-counter medicine. After taking it, not only were her common cold symptoms ameliorated but her akinesia also improved. Among the ingredients of Aneton, codeine phosphate proved to be effective for her akinesia. Case 2 was a man in his 50s with PD accompanied by severe, intermittent pain. Codeine phosphate prescribed for his pain improved both his pain and bradykinesia. The oral administration of codeine phosphate ameliorated akinesia/bradykinesia in both cases of PD. This suggests the possible efficacy of codeine phosphate against motor symptoms in PD. In the future, a well-designed multicenter trial is needed to assess the use of codeine phosphate for PD patients, particularly to evaluate its efficacy for motor symptoms, its adverse effects, and its long-term prognosis in patients with PD.