Successful conversion of patients with hypercholesterolemia from a brand name to a generic cholesterol-lowering drug.
OBJECTIVE
To evaluate the safety and effectiveness of a simvastatin-to-lovastatin therapeutic conversion program.


METHODS
Observational database study of a therapeutic conversion in members of the Northern and Southern California regions of Kaiser Permanente, using a pretest/posttest design.


METHODS
All patients actively converted from simvastatin to lovastatin between April 1, 2002, and March 31, 2003, were identified for inclusion in the analysis. The conversion from simvastatin to lovastatin was based on an equipotent dose ratio of 1 mg of simvastatin to 2 mg of lovastatin. Electronic prescription record and laboratory data were collected for converted patients beginning 365 days before changing therapy through June 30, 2003. The primary effectiveness end point was a comparison of the preconversion and postconversion low-density lipoprotein cholesterol (LDL-C) levels. Safety end points included an analysis of preconversion and postconversion alanine aminotransferase (ALT) tests and creatine kinase values.


RESULTS
A total of 33,318 converted patients met criteria for inclusion in the analysis. The mean LDL-C was lowered from 110.9 to 108.4 mg/dL (P < .001) following the conversion to lovastatin. The percentage of patients with serum ALT levels greater than 3 times the upper limit of normal (ULN) was similar before (0.7%) and after (0.6%) conversion from simvastatin to lovastatin. Creatine kinase elevations greater then 10 times the ULN occurred at similar rates before and after the conversion.


CONCLUSIONS
Overall, patients had an improvement in their lipid profile without evidence of hepatic or muscle enzyme elevations. Appropriately selected patients can be safely and effectively converted from simvastatin to lovastatin.
Cheetham
T Craig
TC
Pharmacy Analytic Service, Kaiser Permanente Southern California, Downey, California 90242, USA. craig.t.cheetham@kp.org
Chan
James
J
Benson
Victor
V
Richmond
Cathlene
C
Levin
Eleanor
E
Campen
David
D
D000368:Aged; D000924:Anticholesteremic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002140:California; D011307:Drug Prescriptions; D016568:Drugs, Generic / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006279:Health Maintenance Organizations; D006801:Humans; D006937:Hypercholesterolemia / Q000188:drug therapy*; D008148:Lovastatin / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D019821:Simvastatin / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
D000924:Anticholesteremic Agents; D016568:Drugs, Generic; D008148:Lovastatin; D019821:Simvastatin