The objective of this study was to assess the effect on serum
lipid levels of the substitution of
simvastatin for
fluvastatin at a dose ratio of 8:1 (
fluvastatin to
simvastatin). A secondary objective was to determine the number of patients at goal
lipid levels before and after this substitution. The study included 60 outpatients with
hyperlipidemia who had received a constant dose of
fluvastatin for at least 6 weeks. After a baseline 12-hour
lipid profile (total
cholesterol,
triglycerides,
high-density lipoprotein, and
low-density lipoprotein [
LDL]) was obtained, patients were switched from
fluvastatin to
simvastatin at an 8:1 dose ratio. Patients were instructed to split the
simvastatin tablets in half with a pill splitter and to take one half-
tablet at bedtime. A repeat
lipid profile and liver function testing were performed after 6 to 8 weeks of
simvastatin therapy.
Lipid components were compared before and during
simvastatin therapy using a paired t test. Target
LDL levels were based on guidelines issued by the National
Cholesterol Education Program. Fifty-six patients completed the study. No change in
lipid components was observed, except for a statistically significant decrease in
LDL. The majority of patients had a decrease in
LDL levels, rather than an increase, after the conversion to
simvastatin. Six patients required a dose increase of
simvastatin in response to increased
LDL levels. Forty-one percent of patients achieved goal
LDL levels with
simvastatin, compared with 30% with
fluvastatin. Four patients withdrew from the study, two because of troublesome side effects and two for failure to complete the protocol. The results show that
simvastatin can be substituted for
fluvastatin at a dose ratio of 8:1 without loss of
lipid control in the majority of patients and that by using this ratio and splitting
tablets, significant cost savings can be realized.