A retrospective, matched cohort study of potential drug-drug interaction prevalence and opioid utilization in a diabetic peripheral neuropathy population initiated on pregabalin or duloxetine.

BACKGROUND: Anticipating and controlling drug-drug interactions (DDIs) in older patients with painful diabetic peripheral neuropaty (pDPN) presents a significant challenge to providers. The purpose of this study was to examine the impact of newly initiated pregabalin or duloxetine treatment on Medicare Advantage Prescription Drug (MAPD) plan pDPN patients' encounters with potential drug-drug interactions, the healthcare cost and utilization consequences of those interactions, and opioid utilization. METHODS: Study subjects required a pregabalin or duloxetine pharmacy claim between 07/01/2008-06/30/2012 (index event), ≥1 inpatient or ≥2 outpatient medical claims with pDPN diagnosis between 01/01/2008-12/31/2012, and ≥12 months pre- and ≥6 post-index enrollment. Propensity score matching was used to balance the pregabalin and duloxetine cohorts on pre-index demographics and comorbidities. Potential DDIs were defined by Micromedex 2.0 and identified by prescription claims. Six-month post-index healthcare utilization (HCU) and costs were calculated using pharmacy and medical claims. RESULTS: No significant differences in pre-index demographics or comorbidities were found between pregabalin subjects (n = 446) and duloxetine subjects (n = 446). Potential DDI prevalence was significantly greater (p < 0.0001) among duoxetine subjects (56.7%) than among pregabalin subjects (2.9%). There were no significant differences in HCU or costs between pregablin subjects with and without a potential DDI. By contrast, duloxetine subjects with a potential DDI had higher mean all-cause costs ($13,908 vs. $9,830; p = 0.001), more subjects with ≥1 inpatient visits (35.6% vs 25.4%; p = 0.02), and more subjects with ≥1 emergency room visits (32.8% vs. 20.7%; p = 0.005) in comparison to duloxetine subjects without a potential DDI. There was a trend toward a difference between pregabalin and duloxetine subjects in their respective pre-versus-post differences in milligrams (mg) of morphine equivalents/30 days used (60.2 mg and 176.9 mg, respectively; p = 0.058). CONCLUSION: The significantly higher prevalence of potential DDIs and potential cost impact found in pDPN duloxetine users, relative to pregabalin users, underscore the importance of considering DDIs when selecting a treatment.

Comparison of Medication Therapy Management Services and Their Effects on Health Care Utilization and Medication Adherence.

BACKGROUND: Medication therapy management (MTM) programs are designed to improve clinical outcomes and enhance appropriate medication use. Comprehensive medication reviews (CMRs) and targeted medication reviews (TMRs) are 2 broad interventions defined within MTM services. While MTM services have been extensively researched, there are few comparisons of CMR versus non-CMR interventions. Given the variability in MTM interventions and lack of a consistent TMR definition in the literature, this study sought to compare CMRs and TMRs that were clearly defined based on Centers for Medicare & Medicaid Services (CMS) criteria. OBJECTIVES: To (a) compare acute inpatient admissions and emergency department (ED) visits between patients participating in MTM services (CMR, TMR, or both) and eligible nonparticipating patients and (b) examine the effect of receiving TMR services on medication adherence. METHODS: This was a retrospective cohort study of patients with Medicare Part D coverage who received MTM services and a 1:1 propensity score-matched control group. Participants had to be eligible for MTM services in 2014 or 2015 based on CMS requirements. CMRs were offered to all MTM-eligible patients, while TMRs were completed based on clinical rules that helped identify medication-related problems (MRPs). The date of MTM intervention, or eligibility for the control group, was considered the index date. Participants had to be continuously enrolled in a Medicare Advantage plan that included prescription drug coverage during the study period and have at least 6 months of data before and after the index date. Medical and pharmacy claims were assessed to examine trend-adjusted inpatient admissions and ED visits from pre-index to post-index date for participants and matched controls. RESULTS: In 2014 and 2015, receipt of TMR interventions was associated with statistically significant reductions in acute inpatient admissions. In 2014, there were 55.2 fewer admits per 1,000 individuals (95% CI = 29-81) and 30.8 fewer admits per 1,000 individuals in 2015 (95% CI = 20-42). Receipt of CMR-only interventions was associated with fewer acute inpatient admissions only when coupled with preidentification of MRPs (36.8 [95% CI = 25-49] fewer admits per 1,000 individuals). In 2015, there were significant reductions in ED visits for participants receiving TMR-only interventions or TMR/CMR interventions (26.1 [95% CI = 11-41] and 12.0 [95% CI = 1-23] fewer ED visits per 1,000 individuals, respectively). In both years, a larger percentage (0.4% for oral diabetes medications; 7.7% for antihypertensives; 3.0% for statins) of MTM participants had greater improvements in medication adherence in the post-index period compared with controls. CONCLUSIONS: Receiving MTM services targeted at resolution of MRPs (TMR or CMR/TMR) resulted in positive reductions in health care utilization and increases in medication adherence. Given the importance of optimal medication utilization, this study highlights the need for additional focus on resolution of MRPs through TMRs and CMRs that can support improved clinical outcomes. DISCLOSURES: No outside funding supported this study. Researchers completed the work as part of their employment with Humana. All authors are or were employees of Humana at the time of the study. There are no other conflicts of interest to disclose. This study was previously presented at AMCP Nexus 2017 on October 16, 2017, in Dallas, TX.

Opioid-paracetamol prescription patterns and liver dysfunction: a retrospective cohort study in a population served by a US health benefits organization.

BACKGROUND: Paracetamol (acetaminophen) is the most common cause of acute liver failure (ALF). ALF attributed to paracetamol is most often associated with the following features: an unintentional overdose, a single product, an opioid-paracetamol combination, duration of <7 days, and a median dose of 7.5 g/day. Currently, the recommended maximum daily dose of paracetamol is 4 g. OBJECTIVES: The aims of the study were to determine opioid-paracetamol prescription patterns, including prescriptions exceeding the recommended dose of paracetamol (4 g/day) [prescriptions and beneficiaries]; examine factors associated with receiving opioid-paracetamol prescriptions in excess of paracetamol 4 g/day; and evaluate opioid-paracetamol prescription patterns for beneficiaries with liver dysfunction. METHODS: A retrospective cohort study examining prescription data of 4.8 million beneficiaries from a US health benefits organization from 1 January 2009 through 31 December 2009. The main outcomes examined were daily paracetamol dose and liver dysfunction. RESULTS: A large proportion (8.1%) of the 5.3 million prescriptions for opioid-paracetamol exceeded the recommended maximum daily dose of paracetamol (4 g/day), putting over one-quarter of a million (255 123 [18.9%]) of the 1.35 million beneficiaries receiving an opioid-paracetamol prescription at risk of toxicity. The most frequently prescribed products that exceeded paracetamol dose guidelines contained dextropropoxyphene and hydrocodone. Multiple factors, including type of product (i.e. dextropropoxyphene or oxycodone-containing), geographical location (Midwest), strength of the paracetamol in the opioid-paracetamol product (>325 mg) and prescriber specialty (dentist, physician assistant), were associated with high-dose paracetamol prescriptions. Liver dysfunction was diagnosed in 3818 cases, and 23.4% of these beneficiaries received an opioid-paracetamol prescription in the 90 days prior to the liver dysfunction diagnosis. CONCLUSIONS: Although most opioid-paracetamol prescriptions are written and dispensed for <4 g/day of paracetamol, a significant portion of beneficiaries are being prescribed and dispensed excessive doses of paracetamol. Efforts to curtail this practice may involve provision of prescriber and pharmacist education, utilization of benefit manager systems to flag excessive dosing or that require confirmation of dosing, and implementation of US FDA recommendations supported by these data.