Evaluation of drug interactions in patients treated with antidepressants at a tertiary care cancer center.

OBJECTIVE: We evaluated potential drug interactions in patients treated with antidepressants at a tertiary care cancer center to determine if it affects resource utilization. METHODS: We identified a cohort of patients with continuous care at the study institution by tagging patients who received at least three prescriptions for antidepressants within a continuous 6-month period. Data collected included demographics, cancer type and comorbidities, resource utilization (hospital and emergency room visits), and potential major drug interactions. Descriptive statistics and logistic regression were utilized in the analysis. RESULTS: The study population, which included 297 patients, was 70% female and 71% Caucasian; the mean age was 53 years (SD, 12 years), with a mean follow-up period (duration of therapy) of 403 days. Overall, 145 (49%) of the patients had a drug combination that could result in a potential major drug interaction with antidepressants. There were 118 (40%) patients with a potential major drug interaction that could lead to serotonin syndrome symptoms and 59 (20%) patients with a potential major drug interaction with anticoagulants. Potential major drug interactions were associated with an increased number of hospital and ER visits (odds ratio [OR], 2.37; 95% confidence interval [CI], 1.39-4.03). This finding was consistent for the two subanalysis groups as well, serotonin syndrome-inducing drugs (OR, 2.28; 95% CI, 1.33-3.92) and anticoagulants (OR, 3.66; 95% CI, 1.85-7.22). CONCLUSION: Potential drug interactions are frequent in patients receiving antidepressants in a tertiary care cancer center and are associated with an increase in resource utilization.

Cancer patients' use of pharmaceutical patient assistance programs in the outpatient pharmacy at a large tertiary cancer center.

PURPOSE: To report on the use of pharmaceutical patient assistance programs (PAPs) in the outpatient pharmacy at the largest tertiary cancer center in the United States. METHODS: We conducted a retrospective (July 1, 2006-Dec 31,2007) cross-sectional analysis of outpatient pharmacy, medical, and cancer registry records at the cancer center. The cancer center identified 104 medications available through PAPs. Study-eligible patients received at least one of these medications, either as a PAP case patient or as a PAP control non-user. Binary logit regression models predicted PAP use, and descriptive statistics compared PAP user and non-user medication fills. RESULTS: Of 25,552 cancer patients at who received an outpatient medication during the study period, 1,929 met study criteria (n=950 PAP users, 979 PAP non-users). In comparison to controls, PAP users were more likely to be uninsured (odds ratio (OR)=4.60, 95% confidence interval (CI): 2.118, 9.970), indigent (OR=16.95, 95% CI: 6.845, 41.960), and < 65 years old (OR=2.31, 95% CI: 1.517, 3.509). Of the most frequently dispensed medications to PAP users from PAPs (n=5,271), 88% (n=4,936) were for supportive care (e.g., nausea/vomiting). PAPs provided 35% (n=842) of the most common anticancer agents administered to PAP users (n=1,296), accounting for a monthly mean of $55,000 in pharmaceutical expenditures. CONCLUSIONS: In the cancer center's outpatient pharmacy, PAPs provided financial support for about a third of the most commonly used therapies, primarily for supportive care indications, for a small percentage of eligible cancer patients.

Evaluation of medication compliance in patients on antidepressants at an outpatient tertiary cancer center setting.

OBJECTIVE: The purpose is to evaluate antidepressant compliance in a cancer population at a tertiary cancer center and to determine if there are covariates of importance in predicting the level of compliance in the study population. METHODS: Patients who received at least three prescriptions covering parts of each month for a continuous 6-month period with at least one of the months being in 2006 from a tertiary cancer center were identified as the prevalent population of interest for this retrospective study. Data collected included demographics, cancer and co-morbid diagnoses, and compliance to antidepressant medication using medication possession ratio (MPR) by patient, medication class, and individual agents. Analysis was conducted using descriptive statistics, analysis of variance, and logistic regression (using MPR ≥ 80 as cutoff). RESULTS: The study population included 297 patients with demographics showing 69% female, 71% Caucasian, a mean age of 52.94 (SD: 12.42), and an average 403 days of follow-up. The MPR for the total study population was 0.87 with 78% of the population having an MPR of ≥ 80% and 22% having an MPR of less than 80%. While there was no significant difference in MPR by different pharmaceutical classes, there were significant differences in the MPR by specific agents (p = 0.02), with nortriptyline having the lowest MPR of 0.79 and doxepin, fluoxetine, mirtazapine, and venlafaxine all having MPR over 0.90. There was also a trend toward a difference in MPR between Caucasians versus non-Caucasians, p = 0.055. CONCLUSION: There appears to be relatively good compliance to antidepressant medications in the study population.

Use of palliative sedation for intractable symptoms in the palliative care unit of a comprehensive cancer center.

BACKGROUND: There is wide variation in the frequency of reported use of palliative sedation (PS) to control intractable and refractory symptoms in terminally ill patients. The aim of this study was to determine the frequency and outcomes of PS use and examine patterns of practice after establishment of a policy for the administration of midazolam for PS in our palliative care unit (PCU). MATERIALS AND METHODS: This retrospective study reviewed PCU admissions for 2004 and 2005 and pharmacy records to identify patients who received chlorpromazine, lorazepam, or midazolam for PS in the PCU. Data on indication for PS, drug used, and discharge outcome were assessed for each patient. RESULTS: During the period studied, there were 1,207 PCU admissions. Of these patients, 186 (15%) received PS; and 143 (41%) of the 352 patients who died in the PCU received PS. The median age of PS patients was 58 (range, 20-84) years, and 106 (57%) were male. The most common indications for PS were delirium, 153 cases (82%); dyspnea, 11 (6%); and multiple indications, 12 (6%). Midazolam was used in 18 PS cases (10%). Six (55%) of 11 patients with dyspnea received midazolam for PS, compared with 12 (7%) of 175 patients with other indications for PS (p < 0.001). Forty-three (23%) of 186 PS patients were discharged alive, compared with 812 (80%) of 1,021 patients who did not receive PS (p < 0.001). CONCLUSIONS: PS was required in 15% of PCU admissions, and 23% of PS patients were discharged alive. Our findings suggest a potential for significant underreporting of overall PS. If our institution's policy on midazolam use for PS were less restrictive, midazolam use might increase. More research is needed to define the optimal agent for inducing rapid, effective, and easily reversible PS.

Disparities in outpatient antidepressant prescribing patterns and determinants of resource utilization at a tertiary care cancer center.

Our objective was to assess the prevalence of use of different classes of antidepressants, prescribing patterns, and determinants of exposure to specific types of antidepressants and resource utilization at a comprehensive cancer center from 2001 to 2006. Data were collected from the institution's outpatient pharmacy database and cross-referenced with the institution's electronic medical record system. Data collected included demographic characteristics, cancer diagnosis, comorbidities, prescribing physician and service, type and number of antidepressant prescriptions, and resource utilization. Significant differences in the usage and prescribing patterns of the type of antidepressants were found in the analysis by gender and ethnicity, with women seeing a psychiatrist more often than men (P = 0.001) and Caucasians receiving more selective serotonin reuptake inhibitors (SSRIs) than other ethnic groups (P = 0.002). In terms of resource utilization, men had significantly more hospital admissions (P < 0.0001) and emergency room visits (P = 0.004) than women, whereas non-Caucasian ethnic groups had more emergency room visits (P < 0.0001) and clinic visits (P = 0.001) than Caucasians. Further investigation of men and non-Caucasians in the screening, evaluation, and treatment of depression is necessary to confirm disparities and evaluate their possible causes.

Prescribing patterns and purchasing costs of long-acting opioids over nine years at an academic oncology hospital.

PURPOSE: The prescribing patterns and purchasing costs of long-acting opioids over nine years at an academic oncology hospital were studied. METHODS: Data were collected for doses of transdermal fentanyl, methadone (all routes of administration), and oral sustained-release morphine and oxycodone dispensed for individual inpatient use for the month of October for each year between 1996 and 2004. The dates included in the retrieval were selected to document long-acting opioid use before and after the establishment of the palliative care and rehabilitation medicine department. For each opioid the number of milligrams dispensed daily per patient was determined and converted into a morphine-equivalent daily dose (MEDD). The average wholesale price per dosing unit of each drug during each period studied was obtained from internal databases. Costs were calculated by multiplying the number of units dispensed by the average wholesale price per unit and then normalized to 1996 U.S. dollars. The mean aggregate cost for a single MEDD in a month was determined by multiplying the mean cost per MEDD for each agent by that agent's percent contribution to the total MEDDs dispensed in that month. RESULTS: Long-acting opioid and methadone usage increased from 1996 to 2004. Between 1996 and 2004, the mean cost of a single MEDD dropped from $0.0738 to $0.0330. During the study period, the median daily cost to treat one patient dropped from $5.96 to $2.80. CONCLUSION: Long-acting opioid use increased and cost per MEDD decreased at an academic oncology hospital between 1996 and 2004. The decreased cost of purchasing opioids was attributed to the increased proportional use of methadone.