Medication adherence and healthcare costs among patients with diabetic peripheral neuropathic pain initiating duloxetine versus pregabalin

CDC Clinical Practice Guideline for Prescribing Opioids for Pain - United States, 2022

This guideline provides recommendations for clinicians providing pain care, including those prescribing opioids, for outpatients aged ≥18 years. It updates the CDC Guideline for Prescribing Opioids for Chronic Pain - United States, 2016 (MMWR Recomm Rep 2016;65[No. RR-1]:1-49) and includes recommendations for managing acute (duration of <1 month), subacute (duration of 1-3 months), and chronic (duration of >3 months) pain. The recommendations do not apply to pain related to sickle cell disease or cancer or to patients receiving palliative or end-of-life care. The guideline addresses the following four areas: 1) determining whether or not to initiate opioids for pain, 2) selecting opioids and determining opioid dosages, 3) deciding duration of initial opioid prescription and conducting follow-up, and 4) assessing risk and addressing potential harms of opioid use. CDC developed the guideline using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Recommendations are based on systematic reviews of the scientific evidence and reflect considerations of benefits and harms, patient and clinician values and preferences, and resource allocation. CDC obtained input from the Board of Scientific Counselors of the National Center for Injury Prevention and Control (a federally chartered advisory committee), the public, and peer reviewers. CDC recommends that persons with pain receive appropriate pain treatment, with careful consideration of the benefits and risks of all treatment options in the context of the patient's circumstances. Recommendations should not be applied as inflexible standards of care across patient populations. This clinical practice guideline is intended to improve communication between clinicians and patients about the benefits and risks of pain treatments, including opioid therapy; improve the effectiveness and safety of pain treatment; mitigate pain; improve function and quality of life for patients with pain; and reduce risks associated with opioid pain therapy, including opioid use disorder, overdose, and death.

Effects of dose titration on adherence and treatment duration of pregabalin among patients with neuropathic pain: A MarketScan database study

OBJECTIVE

To examine pregabalin dose titration and its impact on treatment adherence and duration in patients with neuropathic pain (NeP).

METHODS

MarketScan database (2009-2014) was used to extract a cohort of incident adult pregabalin users with NeP who had at least 12 months of follow-up data. Any dose augmentation within 45 days following the first pregabalin claim was defined as dose titration. Adherence (measured by medication possession ratio/MPR) and persistence (measured as the duration of continuous treatment) were compared between the cohorts with and without dose titration. Logistic regressions and Cox proportional hazards models were used to identify the factors associated with adherence (MPR ≥ 0.8) and predictors of time to discontinuation.

RESULTS

Among the 5,186 patients in the analysis, only 18% of patients had dose titration. Patients who had dose titration were approximately 2.6 times as likely to be adherent (MPR ≥ 0.8) (odds ratio = 2.59, P < 0.001) than those who did not have dose titration. Kaplan-Meier analysis shows that the time to discontinuation or switch was significantly longer among patients who had dose titration (4.99 vs. 4.04 months, P = 0.009).

CONCLUSIONS

Dose titration was associated with improved treatment adherence and persistence among NeP patients receiving pregabalin. The findings will provide valuable evidence to increase physician awareness of dose recommendations in the prescribing information and to educate patients on the importance of titration and adherence.

Duloxetine protects against experimental diabetic retinopathy in mice through retinal GFAP downregulation and modulation of neurotrophic factors

Diabetic retinopathy (DR) is recognized as one of the leading causes of blindness worldwide. Searching and validation for a novel therapeutic strategy to prevent its progress are promising. This work aimed to assess the retinal protective effects of duloxetine (DLX) in Alloxan-induced diabetic mice model. Animals were equally and randomly divided to four groups (eight mice per group); group 1: is the control group, 2: diabetic group, 3&4: diabetic and after 9 weeks received DLX for 4 weeks (15 mg/kg and 30 mg/kg), respectively. Quantitative real-time PCR (qPCR) analysis revealed nerve growth factor (NGF), inducible nitric oxide synthase (iNOS) and transforming growth factor beta (TGF-β) genes upregulation in the diabetic group compared to controls. Also, increased retinal malondialdehyde (MDA) and the decline of reduced glutathione (GSH) levels were observed. The morphometric analysis of diabetic retina revealed a significant reduction in total retinal thickness compared to control. Diabetic retinal immunostaining and Western blot analyses displayed glial fibrillary acidic protein (GFAP) and vascular endothelial cell growth factor (VEGF) proteins expression upregulation as well as glucose transporter-1 (GLUT-1) downregulation comparing to controls. However, DLX-treated groups showed downregulated NGF, iNOS, and TGF-β that was more obviously seen in the DLX-30 mg/kg group than DLX-15 mg/kg group. Furthermore, these groups showed amelioration of the oxidative markers; MDA and GSH, retaining the total retinal thickness nearly to control, GFAP and VEGF downregulation, and GLUT-1 upregulation compared to diabetic group. Taken together, it could be summarized that duloxetine can attenuate DR via the anti-inflammatory and the anti-oxidative properties as well as modulating the angiogenic and the neurotrophic factors expressions. This could hopefully pave the road to be included in the novel list of the therapeutic regimen for DR after validation in the clinic.

Long-term cost-effectiveness of initiating treatment for painful diabetic neuropathy with pregabalin, duloxetine, gabapentin, or desipramine

Painful diabetic neuropathy (PDN) affects nearly half of patients with diabetes. The objective of this study was to compare the cost-effectiveness of starting patients with PDN on pregabalin (PRE), duloxetine (DUL), gabapentin (GABA), or desipramine (DES) over a 10-year time horizon from the perspective of third-party payers in the United States. A Markov model was used to compare the costs (2013 $US) and effectiveness (quality-adjusted life-years [QALYs]) of first-line PDN treatments in 10,000 patients using microsimulation. Costs and QALYs were discounted at 3% annually. Probabilities and utilities were derived from the published literature. Costs were average wholesale price for drugs and national estimates for office visits and hospitalizations. One-way and probabilistic (PSA) sensitivity analyses were used to examine parameter uncertainty. Starting with PRE was dominated by DUL as DUL cost less and was more effective. Starting with GABA was extendedly dominated by a combination of DES and DUL. DES and DUL cost $23,468 and $25,979, while yielding 3.05 and 3.16 QALYs, respectively. The incremental cost-effectiveness ratio for DUL compared with DES was $22,867/QALY gained. One-way sensitivity analysis showed that the model was most sensitive to the adherence threshold and utility for mild pain. PSA showed that, at a willingness-to-pay (WTP) of $50,000/QALY, DUL was the most cost-effective option in 56.3% of the simulations, DES in 29.2%, GABA in 14.4%, and PRE in 0.1%. Starting with DUL is the most cost-effective option for PDN when WTP is greater than $22,867/QALY. Decision makers may consider starting with DUL for PDN patients.

Cost-Effectiveness of Capsaicin 8% Patch Compared with Pregabalin for the Treatment of Patients with Peripheral Neuropathic Pain in Scotland

We evaluated the cost-effectiveness of capsaicin 8% patch (QUTENZA™) versus pregabalin in patients with PNP from the perspective of the National Health Service (NHS) and Personal and Social Services in Scotland, UK. A decision-tree cost-effectiveness model was developed for non-diabetic patients with peripheral neuropathic pain (PNP) who were pregabalin-naïve and had not achieved adequate pain relief or tolerated conventional first- or second-line treatments. Patients entering the model received either a single application of capsaicin 8% patch or titrated daily dosing with pregabalin; after 8 weeks patients were classified as responders, non-responders, or were assumed to discontinue treatment due to intolerable adverse events. Responders continued to receive baseline treatment at intervals observed in clinical practice. Non-responders and those who discontinued treatment were assumed to receive last-line therapy (duloxetine). The base-case time horizon was 2 years. Model inputs for effectiveness, discontinuations and health-state utilities were taken from a head-to-head non-inferiority study (ELEVATE, NCT01713426). Other inputs were obtained from published sources or clinical expert opinion. Costs were expressed in GBP 2013/14. Results were presented as incremental cost-effectiveness ratios (ICER), i.e. cost per quality-adjusted life-year (QALY) gained. Model assumptions were tested with scenario analyses. Parameter uncertainty was tested using one-way and probabilistic sensitivity analyses. Compared with dose-optimized pregabalin, capsaicin 8% patch was the dominant treatment strategy (total cost difference, –£11; total QALY gain, 0.049). Capsaicin 8% patch was also the dominant treatment strategy versus pregabalin in 6 out of 7 scenario analyses. The model was most sensitive to variation in time to capsaicin 8% patch retreatment (maximum ICER, £7,951/QALY at lower-bound 95% confidence interval). At a willingness-to-pay threshold of £20,000/QALY, the probability of capsaicin 8% patch being cost-effective versus pregabalin was 97%. Capsaicin 8% patch is a cost-effective treatment option compared with dose-optimized pregabalin in patients with PNP who have failed one or more previous systemic treatments.

A review of the clinical utility of duloxetine in the treatment of diabetic peripheral neuropathic pain

Diabetes mellitus is a world-wide epidemic with many long-term complications, with neuropathy being the most common. In particular, diabetic peripheral neuropathic pain (DPNP), can be one of the most distressing complications associated with diabetes, leading to decreases in physical and mental quality of life. Despite the availability of many efficient medications, DPNP remains a challenge to treat, and the optimal sequencing of pharmacotherapy remains unknown. Currently, there are only three medications approved by the US Food and Drug Administration specifically for the management of DPNP. Duloxetine (DUL), a selective serotonin-norepinephrine reuptake inhibitor, is one of these. With the goal of optimizing pharmacotherapy use in DPNP population, a review of current literature was conducted, and the clinical utility of DUL described. Along with early clinical trials, recently published observational studies and pharmacoeconomic models may be useful in guiding decision making by clinicians and managed care organizations. In real-world practice settings, DUL is associated with decreased or similar opioid utilization, increased medication adherence, and similar health care costs compared with current standard of care. DUL has consistently been found to be a cost-effective option over short time-horizons. Currently, the long-term cost-effectiveness of DUL is unknown. Evidence derived from randomized clinical trials, real-world observations, and economic models support the use of DUL as a first-line treatment option from the perspective of the patient, clinician, and managed care payer.

Duloxetine treatment adherence across mental health and chronic pain conditions

PURPOSE

This study applied a uniform methodology for measuring and comparing duloxetine adherence in the treatment of multiple chronic medical conditions.

MATERIALS AND METHODS

Study patients 18-64 years of age initiating duloxetine therapy during 2008 were identified from a large managed care database. The study was restricted to patients with continuous health plan eligibility for 12 months pre- and post-duloxetine initiation. Study patients had ≥1 medical claim with an inpatient or outpatient diagnosis of one (and only one) of the following conditions: major depressive disorder (MDD); generalized anxiety disorder (GAD); fibromyalgia, diabetic peripheral neuropathic pain; or chronic musculoskeletal pain, as established in studies in patients with osteoarthritis and chronic lower back pain (CLBP). Patients initiating duloxetine who had two or more of the six studied conditions were not included in this study, thereby avoiding the need to differentiate between primary and secondary diagnoses from the claims records. Adherence rate was defined as the percentage of patients with a 365-day medication possession ratio ≥0.8.

RESULTS

A total of 20,490 patients initiated duloxetine treatment during 2008 with a diagnosis of one of the studied conditions during the study period. The adherence rate in our sample was 34.6% and was highest among patients with MDD (37.3%) and lowest for patients with CLBP (29.9%). In general, adherence among patients with MDD and GAD was greater than among those with a chronic pain condition.

CONCLUSION

Adherence among newly initiated duloxetine patients varied modestly across the medical conditions for which it was used. After adjusting for potential confounders, differences between the mental conditions (MDD and GAD) and the chronic pain conditions (CLBP, osteoarthritis, and diabetic peripheral neuropathic pain) were statistically significant. These results may be useful in the determination of expectations of adherence, and how it may differ for each of the conditions studied.

Pharmacoeconomic outcomes for pregabalin: a systematic review in neuropathic pain, generalized anxiety disorder, and epilepsy from a Spanish perspective

INTRODUCTION

Pregabalin is an anticonvulsant approved in Europe for the treatment of neuropathic pain, as an adjunct therapy for epileptic seizures, and recently for generalized anxiety disorder. The aim of this study was to conduct a systematic review to evaluate the cost-effectiveness of pregabalin associated with the treatment of its labeled indications from a societal perspective in Spain.

METHODS

Data from the MEDLINE database were searched using algorithms to identify relevant economic evaluations published in English or Spanish on pregabalin for the management of neuropathic pain, generalized anxiety disorder (GAD), and epilepsy in Spanish patients over the last 10 years.

RESULTS

In total, 52 potentially relevant abstracts were identified from the MEDLINE database. Twenty manuscripts met the inclusion criteria. The majority of the selected papers (14/20) evaluated pregabalin for neuropathic pain from a societal perspective in Spain (5 economic models of pregabalin vs. gabapentin, 4 economic analyses of pregabalin in comparison with usual care, 4 economic evaluations comparing pregabalin monotherapy with add-on strategies, and one that evaluated different times of initiating pregabalin therapy). Five studies analyzed the use of pregabalin in Spain for the management of GAD (one cost-effectiveness model that compared pregabalin with venlafaxine, 2 secondary analyses in benzodiazepine-refractory patients, and 2 studies evaluating pregabalin vs. usual care in patients refractory to standard regimens). The last manuscript described a cost-effectiveness model that compared pregabalin versus levetiracetam use for the treatment of refractory partial epilepsy.

CONCLUSION

The majority of published evidence supports the possibility that pregabalin could be a cost-effective and/or cost-saving alternative for the treatment of refractory epilepsy, GAD, and neuropathic pain, in both treatment-naïve patients and in those who have demonstrated inadequate response or intolerance to previous therapy.

Identification of patients with painful diabetic peripheral neuropathy who have a favorable cost profile with pregabalin treatment

OBJECTIVE

To characterize patient populations with favorable costs after the initiation of pregabalin for the treatment of painful diabetic peripheral neuropathy (pDPN) relative to duloxetine, gabapentin, and amitriptyline.

METHODS

Patients were identified from MarketScan having ≥ 1 claim for pDPN (ICD-9-CM codes 250.6 or 357.2) within 60 days of first prescription (index) for pregabalin, duloxetine, gabapentin, or amitriptyline in 2008 and continuous enrollment 12 months pre- and postindex. Pregabalin patients were propensity-score-matched to each comparator. Using cutoff values ≥ 80% proportion of days covered (PDC) and ≥ 65 years for age, pre- to postindex changes in healthcare costs were estimated for pregabalin vs. comparators.

RESULTS

Of 987 patients initiated on pregabalin, 349 matched to duloxetine; 987 to gabapentin; 276 to amitriptyline. The pre- to postindex changes in total healthcare costs were similar between cohorts: $3272 with pregabalin vs. $2290 with duloxetine (P = 0.5280); $3687 with pregabalin vs. $5498 with amitriptyline (P = 0.5863); $3869 with pregabalin vs. $4106 with gabapentin (P = 0.8303). For the high-age/high-PDC population, the pre- to postindex differences in mean total costs were significantly lower with pregabalin (P < 0.001) relative to comparators ($3573 vs. $8288 for duloxetine; $1423 vs. $3167 for gabapentin; $2285 vs. $6160 for amitriptyline).

CONCLUSIONS

The association of lower total costs among older individuals with pDPN who maintain high adherence to pregabalin therapy relative to key comparators suggests a pharmacoeconomic advantage of pregabalin in this population combined with a need for strategies promoting adherence.

Opioids before and after initiation of pregabalin in patients with diabetic peripheral neuropathy

OBJECTIVES

To examine opioid prescription claims before and after initiation of pregabalin in patients with a diagnosis of diabetic peripheral neuropathy (DPN).

METHODS

This retrospective analysis used a national commercial database of integrated inpatient, outpatient, and prescription claims to identify adults with a DPN diagnosis code within 360 days prior to the first claim for pregabalin between January 1, 2006 and March 31, 2008. Prescription claims for pregabalin or opioids were analyzed in nine consecutive 60-day periods from 180 days before through 360 days after the first pregabalin claim. It was not possible to establish drug administration dates, compliance rates, indications for opioid use, or reasons for treatment discontinuation.

RESULTS

Of the 8004 adults who met eligibility criteria, 6080 (76%) received an opioid within the 180 days before and/or 360 days after their first prescription for pregabalin, including 3956 (49%) both before and after, 1580 (20%) after only, and 544 (7%) before only. The percentage of patients with pregabalin claims covering ≥20 of 60 days (within 60-day periods) was 99% (day 1-60), 63% (day 61-120), 50% (day 121-180), 45% (day 181-240), 42% (day 241-300), and 39% (day 301-360). The percentage of patients with opioid claims covering ≥20 of 60 days within the 60-day periods remained stable (range, 25-30%). Among patients with opioid claims, 73-76% received only short-acting opioids, 6-7% received only long-acting opioids, and 18-20% received both short- and long-acting opioids. In the first year, 982 (12%) patients had opioid claims covering ≥20 of 60 days in every 60-day period (i.e., persistent use of opioids). Coexisting musculoskeletal (95%) or neuropathic (61%) pain conditions were frequent.

CONCLUSION

A majority of patients with DPN receive an opioid before and/or after their first pregabalin claim. Pregabalin neither interferes with nor replaces opioid use for pain management in patients with DPN. Although nearly 1 in 8 patients received opioids throughout the study period, most claims were for short-acting opioids. The majority of this DPN sample had other pain conditions, including musculoskeletal and neuropathic pain conditions. These results highlight the frequency of opioid use with pregabalin, particularly short-acting opioids.

Use of select medications prior to duloxetine initiation among commercially-insured patients

BACKGROUND

The purpose of this study was to assess select medication utilization prior to duloxetine initiation among patients with major depressive disorder, generalized anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia, and musculoskeletal pain associated with osteoarthritis or low back pain.

METHODS

Commercially insured duloxetine initiators between January 1, 2007 and March 31, 2010 were identified from a large US administrative claims database. Disease subgroups were constructed based on diagnosis from medical claims during the 12 months prior to duloxetine initiation. Prior use of antidepressants, anticonvulsants, opioids, nonsteroidal anti-inflammatory drugs, and muscle relaxants was assessed during the 12-month preinitiation period.

RESULTS

This study identified 56,845 (2007), 44,838 (2008), and 65,840 (January 2009 to March 2010) duloxetine initiators. Among the 2009 initiators, utilization patterns were similar for patients with major depressive disorder and generalized anxiety disorder, with antidepressants being the most used (84% and 80%, respectively), followed by opioids (58% and 55%, respectively). Patients across pain-related conditions also had similar utilization patterns, with opioid use being the highest (76%-82%), followed by antidepressants (65%-72%). Use of other medication classes was common (29%-63%) but less frequent, and over 50% of the patients used any antidepressants, 70% used any antidepressants or anticonvulsants, and 90% used any antidepressants, anticonvulsants, or opioids. Trends in the use of these select medications were similar between 2007 and 2009.

CONCLUSION

Patients used several types of medications over the 12 months prior to initiating duloxetine across disease states, with antidepressants and opioids being the most frequently used medications. Trends of select medication use were similar over time.

Dosing pattern comparison between duloxetine and pregabalin among patients with diabetic peripheral neuropathic pain

OBJECTIVE

To compare medication dosing patterns of duloxetine and pregabalin among patients with diabetic peripheral neuropathic pain (DPNP).

METHODS

Applying a retrospective cohort study design on a large U.S. healthcare claims database, we examined the dosing patterns of duloxetine and pregabalin among commercially insured patients with DPNP aged 18 to 64 who initiated (a 90-day medication gap) duloxetine or pregabalin therapy in 2006. Selected patients had continuous enrollment during the 12-month pre- and post-index periods. The index mediation was used to classified individuals into the duloxetine or pregabalin cohorts. Initial daily dose, average daily dose over the first post-index year, and average daily dose of the first several prescriptions were estimated and compared across the cohorts.

RESULTS

The study sample included 828 duloxetine and 1934 pregabalin-treated patients with a mean age of 50 years. Cardiovascular diseases, neuropathic pain other than DPNP, osteoarthritis, and diabetic retinopathy were the most common comorbid conditions. The average initial daily doses were 54.3 and 171.8 mg for duloxetine and pregabalin, respectively. The average daily dose over the first post-index year was 55.2 mg for duloxetine and 173.8 mg for pregabalin. The average daily dose for the first 10 duloxetine prescriptions ranged between 54.3 and 61.9 mg, but increased from 171.8 to 264.3 mg for pregabalin.

CONCLUSIONS

The commercially insured patients with DPNP who initiated duloxetine or pregabalin therapy had different dosing patterns. The average daily dose for duloxetine was relatively stable over time, while pregabalin-treated patients had significant dose increase over the 12-month post-index period.

Factors associated with pain medication selection among patients diagnosed with diabetic peripheral neuropathic pain: a retrospective study

OBJECTIVE

To assess the demographic and clinical characteristics associated with initiation of duloxetine therapy compared with other pharmacologic therapies for treatment of diabetic peripheral neuropathic pain (DPNP).

METHODS

This study used administrative claims databases for commercially-insured individuals aged 18-64 years to examine factors associated with treatment among DPNP patients who initiated duloxetine versus tricyclic antidepressants (TCAs), venlafaxine, gabapentin, pregabalin, or opioids between 7/1/2005 and 12/31/2007. Treatment initiation was defined as no pill coverage of the same medication over the previous 90 days. Multiple logistic regression models were estimated to assess factors associated with initiating duloxetine versus each of the other DPNP therapies.

RESULTS

The study included 11,060 DPNP patients with average age of 55 years old. Cardiovascular disease (63-70%), cerebrovascular/peripheral vascular disease (26-33%), low back pain (24-39%), and osteoarthritis (17-26%) were the most common diabetes- and pain-related comorbidities. Controlling for demographic and clinical characteristics, patients who received duloxetine or pregabalin in the prior 12-month period were more likely to initiate duloxetine. Patients from other DPNP treatment cohorts, except for those in the pregabalin cohort, were more likely to re-initiate the same prior therapy than begin treatment with duloxetine (all p<0.05). A history of anxiety disorder was significantly associated with initiation of all DPNP treatments other than duloxetine (all p<0.05), except for TCAs. Patients with low back pain were more likely to initiate duloxetine than TCAs or venlafaxine, but less likely to initiate duloxetine than pregabalin or opioids. Patients with infections related to diabetes were less likely to initiate duloxetine than venlafaxine, gabapentin, or opioids.

LIMITATIONS

Because a retrospective administrative claims database was used, this study is subject to selection bias due to unobservable confounders, inability to measure prescriber preferences or characteristics or disease severity.

CONCLUSIONS

Among commercially-insured DPNP patients, those with prior use of duloxetine or pregabalin were more likely to initiate duloxetine than other treatments. The presence of select comorbidities was also associated with specific medication initiation.