COMT genotype and effectiveness of entacapone in patients with fluctuating Parkinson's disease

OBJECTIVE: To investigate the relationship between the catechol-O-methyltransferase (COMT) genotype and the therapeutic efficacy of entacapone. METHODS: The efficacy of 2 months of entacapone treatment in 65 patients with PD with end-of-dose deterioration was studied. The efficacy of entacapone was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) score, the daily levodopa dosage, and the patients' diary card. RESULTS: Thirty-six patients (55.4%) had a high-activity COMT gene (COMT(HH)), 22 (33.8%) had an intermediate-activity COMT gene (COMT(HL)), and 7 patients (10.8%) had a low-activity COMT gene (COMT(LL)). Two months of entacapone treatment resulted in a significant increase in "on" time, a reduction in "off" time, and a reduction in the total UPDRS score, but these results were independent of the COMT genotype of the patient. There was no significant difference in the frequency or severity of dyskinesias between the patients with different COMT genotypes. CONCLUSION: The COMT genotype seems to be a minor factor in judging the beneficial effects of entacapone administration.