Community and long-term care management of Parkinson's disease in the elderly: focus on monoamine oxidase type B inhibitors.

Parkinson's disease affects up to 1 million people in the US, most of them elderly. Motor and non-motor symptoms can be significantly disabling to the point of necessitating institutionalisation. Age-related changes in drug absorption, distribution, metabolism and excretion complicate the treatment of elderly patients with Parkinson's disease. General management principles include initiation of medication at low doses with gradual titration based on clinical effects, avoidance of certain classes of drugs (e.g. anticholinergics), and attention to polypharmacy and its risk for potentially toxic drug interactions. Levodopa remains the most efficacious anti-Parkinson's disease medication and should be the cornerstone of therapy in the elderly Parkinson's disease patient. Use of dopamine receptor agonists, amantadine and anticholinergic drugs in the elderly is limited by high risk for psychotoxicity. Catechol-O-methyltransferase inhibitors may be used to augment levodopa in the setting of 'wearing off' (i.e. motor fluctuations). Monoamine oxidase type B (MAO-B) inhibitors can be used across the spectrum of disease severity, but selegiline (deprenyl), the prototype in this class, is characterised by low and erratic bioavailability of the parent drug and conversion to amphetamine metabolites that may increase the risk of adverse events. A new orally disintegrating tablet formulation overcomes some of these limitations. Rasagiline is a new, selective, second-generation MAO-B inhibitor that is chemically and metabolically distinct from selegiline. The favourable safety profile of rasagiline in the elderly and its once-daily formulation may maximise drug adherence and improve outcomes.