The angiotensin converting enzyme (ACE) inhibitor, perindopril, modifies the clinical features of Parkinson's disease

Background: Animal studies have demonstrated an interaction within the striatum between the angiotensin and dopaminergic systems. In rats, the angiotensin converting enzyme (ACE) inhibitor, perindopril, crosses the blood brain barrier and increases striatal dopamine synthesis and release. In humans, angiotensin type 1 receptors have been found on dopaminergic neurons in the substantia nigra and striatum. In Parkinson's disease, there is a marked reduction of these receptors associated with the nigrostriatal dopaminergic neuron loss. Aims: We performed a double blind placebo controlled crossover pilot study in seven patients to investigate the effect of the ACE inhibitor, perindopril on the clinical features of moderately severe Parkinson's disease. Results: After a four week treatment period with perindopril, patients had a faster onset in their motor response to L-dopa and a reduction in 'on phase' peak dyskinesia, p=0.021 and p=0.014 respectively. Patients also reported more 'on' periods during their waking day in their movement diary, p=0.007. Perindopril was well tolerated without any significant postural hypotension or renal dysfunction. Conclusions: These results suggest that ACE inhibitors such as perindopril may have a place in the management of motor fluctuations and dyskinesia in Parkinson's disease and justify further study.