A risk-benefit assessment of drugs used in the management of Parkinson's disease.

The introduction of levodopa therapy in the 1960s and subsequent advances in neuropharmacology have revolutionised the management of Parkinson's disease but at a cost. Adverse effects are common, and an erratic pattern of response may develop with long term therapy due to a poorly understood interaction between drug treatment and disease progression. Not all features of the disease respond to drugs, and certain aspects such as psychiatric symptoms and postural imbalance may indeed be exacerbated. Patients vary considerably in their tolerance of anti-Parkinsonian drugs. Individual assessment of each patient's medical, psychiatric and functional problems is required, with ongoing review and dose titration as the disease progresses. In recent years there has been increasing interest in whether it is possible to influence the progression of Parkinson's disease. As a result more complicated drug regimens are being advocated for use in newly diagnosed patients. Arguments for and against this approach, as opposed to traditional symptomatic treatment, are presented.