Risk of constipation in patients prescribed fentanyl transdermal system or oxycodone hydrochloride controlled-release in a California Medicaid population.
OBJECTIVE
To compare the risk of developing constipation between patients prescribed fentanyl transdermal system or oxycodone hydrochloride (HCl) controlled-release.


METHODS
California Medicaid (Medi-Cal) claims data.


METHODS
Medicaid beneficiaries in California.


METHODS
Chronic pain patients who received a prescription for transdermal fentanyl or oxycodone controlled-release between October 1, 1997, and February 28, 2000, for at least three consecutive months.


METHODS
Constipation was defined using the International Classification of Diseases, Ninth Revision, Clinical Modification code (ICD-9-CM 564.0). The association between long-acting opioid use and constipation was determined by multivariate logistic regression after controlling for drug strength, short-acting opioid usage, and comorbidities. Odds ratios (ORs), 95% confidence intervals (CIs), and P values were reported.


RESULTS
A total of 2,095 patients were included in the regression analysis (transdermal fentanyl = 877; oxycodone controlled-release = 1,218). Seventy-five patients received a constipation diagnosis (transdermal fentanyl = 28; oxycodone controlled-release = 47). Approximately 40% of patients were at least 65 years of age. Overall, oxycodone controlled-release patients had a significantly greater risk of developing constipation compared with transdermal fentanyl patients (transdermal fentanyl: n = 877; oxycodone controlled-release: n=1,218; OR = 2.55; 95% CI = 1.33-4.89; P = 0.005). Among patients who were 65 years or older, oxycodone controlled-release patients were 7.33 times more likely to be constipated than transdermal fentanyl patients (transdermal fentanyl: n = 518; oxycodone controlled-release: n = 317; OR = 7.33; 95% CI = 1.98-27.13; P = 0.003).


CONCLUSIONS
These findings suggest that patients prescribed transdermal fentanyl may have a significantly lower risk of developing constipation compared with oxycodone controlled-release, particularly in the elderly.
Covance Health Economics and Outcomes Services, Inc., Gaithersburg, MD 20878, USA. stacey.ackerman@covance.com
Stacey J
SJ
Ackerman
Tyler
T
Knight
Jeff
J
Schein
Chureen
C
Carter
Peter
P
Staats