Treatment of Parkinson's Disease with levodopa and amantadine used as single drugs and in combined therapy

Summary

TWENTY four patients with Parkinson's Disease divided into four groups were studied for a period of 12 weeks. The effects of levodopa and amantadine used as single drugs were compared with amantadine and levodopa in combined therapy. Both drugs were found to be effective with greater improvement for levodopa especially for physical signs in Group 1. No advantage was noted on combined therapy over a period of four weeks, but it is suggested that further improvement might occur after a more prolonged period of treatment now under evaluation. A variable response to treatment in different groups despite similar disability and drug dosage was noted.

Major side effects occurred with both drugs. Gastrointestinal symptoms and dyskinetic movements were more common with levodopa, while hallucinaions, oedema and confusion occurred with amantadine. The number of side effects in Groups 3 and 4 increased when both drugs were combined. It is suggested that the erythema of the hands which occurred on combined therapy could be due to physiological changes in skin blood vessels, possibly due to amantadine. One positive direct Coombs' test and one raised serum uric acid were found. The positive Coombs' test was not associated with haemolytic anaemia. All other tests for toxicity were normal.