Pharmacoeconomic Analysis of Using Sinemet CR over Standard Sinemet in Parkinsonian Patients with Motor Fluctuations

Abstract

OBJECTIVE:

To compare the costs of pharmacotherapy in patients with Parkinson's disease before and after converting from standard Sinemet to extended-release Sinemet CR.

DESIGN:

Investigators retrospectively reviewed records of patients converting from Sinemet to Sinemet CR for efficacy and total drug costs. Cost-effectiveness was evaluated retrospectively from data collected in prospective Sinemet CR efficacy trials.

SETTING:

Parkinson's disease clinic at a tertiary care university teaching hospital.

PATIENTS:

100 patients with motor fluctuations who had undergone an initial 6-month course of Sinemet therapy, followed by a 6-month course of Sinemet CR.

MAIN OUTCOME MEASURES:

Total cost was measured as the cost of Sinemet formulations plus the costs of other antiparkinson medications. Differences in pre- and postconversion costs were compared by using the paired, two-tailed Student's t-test. A substudy of 39 patients on the cost-effectiveness of conversion measured the ratio of daily medication costs to the daily hours “on” without chorea.

RESULTS:

While total daily medication costs after conversion increased by 21%, patients experienced either a comparable or an improved degree of disease control with Sinemet CR. Patients who were also taking selegiline were able to decrease selegiline expense by 20%. The costs of other adjunctive medications did not differ significantly after conversion. The cost-effectiveness analysis revealed an increase in postconversion on time by 2.2 hours (p = 0.0001), accompanied by a $2.85 decrease in total cost per hour on without chorea (p = 0.11).

CONCLUSIONS:

Although Sinemet CR is more costly, it may be more cost-effective in patients with motor fluctuations. Some patients may be able to reduce adjunctive medications.