Evaluation of clinical and safety outcomes associated with conversion from brand-name to generic tacrolimus in transplant recipients enrolled in an integrated health care system.
OBJECTIVE
To evaluate clinical and safety outcomes among transplant recipients whose tacrolimus was converted from the brand-name formulation to a generic formulation.


METHODS
Retrospective analysis.


METHODS
Clinical databases and electronic records from a large, integrated health care system in California.


METHODS
A total of 234 clinically stable, adult transplant recipients (renal, liver, and heart) whose tacrolimus was converted from the brand-name formulation to a generic formulation between October 1, 2010, and December 31, 2010, according to a physician-approved protocol.


RESULTS
For each patient, pre- and postconversion tacrolimus trough concentrations and serum creatinine concentrations were analyzed. Data were also collected on the percentage of patients who required dosage titration, drug cost savings, and rates of reversion to brand-name tacrolimus, biopsy-proved acute allograft rejections, and mortality. No significant differences were noted in mean ± SD pre- and postconversion tacrolimus trough levels (6.74 ± 1.61 vs 6.96 ± 2.31 ng/ml, p=0.137) or serum creatinine concentrations (1.33 ± 0.48 vs 1.36 ± 0.82 mg/dl, p=0.302). The mean ± SD percent change in tacrolimus trough concentration was 5.63 ± 32.95%. Thirty-six patients (15.4%) required dosage titration. Six patients (2.6%) reverted back to brand-name tacrolimus. No deaths or acute rejections occurred. Use of the generic product saved each patient an average of $45/month in drug acquisition cost and $26/prescription copayment.


CONCLUSIONS
Clinical experience as well as research data show that use of generic tacrolimus results in trough concentrations that are comparable to the brand-name drug. Given the lack of adverse events reported and the cost savings recognized, conversion from brand-name tacrolimus to generic tacrolimus should be encouraged. Since dosage titration may be required, close therapeutic drug monitoring is recommended.
Pharmacy Outcomes Research Group, Kaiser Permanente, Downey, California 90242, USA. michele.m.spence@kp.org
Michele M
MM
Spence
Lynda M
LM
Nguyen
Rita L
RL
Hui
James
J
Chan
D000328:Adult; D000368:Aged; D002140:California / Q000453:epidemiology; D017046:Cost Savings; D016527:Drug Costs; D016903:Drug Monitoring; D016568:Drugs, Generic / Q000009:adverse effects / Q000191:economics / Q000493:pharmacokinetics / Q000627:therapeutic use*; D057286:Electronic Health Records; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000453:epidemiology / Q000517:prevention & control; D016027:Heart Transplantation / Q000009:adverse effects / Q000191:economics / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000191:economics / Q000493:pharmacokinetics / Q000627:therapeutic use*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000191:economics / Q000276:immunology*; D016031:Liver Transplantation / Q000009:adverse effects / Q000191:economics / Q000276:immunology*; D008297:Male; D008329:Managed Care Programs; D008875:Middle Aged; D012189:Retrospective Studies; D016559:Tacrolimus / Q000009:adverse effects / Q000191:economics / Q000493:pharmacokinetics / Q000627:therapeutic use*; D013810:Therapeutic Equivalency
D016568:Drugs, Generic; D007166:Immunosuppressive Agents; D016559:Tacrolimus