Predictors of pain medication selection among patients diagnosed with fibromyalgia

Analgesic Medication in Fibromyalgia Patients: A Cross-Sectional Study

There is no approved drug for fibromyalgia syndrome (FMS) in Europe. In the German S3 guideline, amitriptyline, duloxetine, and pregabalin are recommended for temporary use. The aim of this study was to cross-sectionally investigate the current practice of medication in FMS patients in Germany. We systematically interviewed 156 patients with FMS, while they were participating in a larger study. The patients had been stratified into subgroups with and without a decrease in intraepidermal nerve fiber density. The drugs most commonly used to treat FMS pain were nonsteroidal anti-inflammatory drugs (NSAIDs) (41.0% of all patients), metamizole (22.4%), and amitriptyline (12.8%). The most frequent analgesic treatment regimen was “on demand” (53.9%), during pain attacks, while 35.1% of the drugs were administered daily and the remaining in other regimens. Median pain relief as self-rated by the patients on a numerical rating scale (0–10) was 2 points for NSAIDS, 2 for metamizole, and 1 for amitriptyline. Drugs that were discontinued due to lack of efficacy rather than side effects were acetaminophen, flupirtine, and selective serotonin reuptake inhibitors. Reduction in pain severity was best achieved by NSAIDs and metamizole. Our hypothesis that a decrease in intraepidermal nerve fiber density might represent a neuropathic subtype of FMS, which would be associated with better effectiveness of drugs targeting neuropathic pain, could not be confirmed in this cohort. Many FMS patients take “on-demand” medication that is not in line with current guidelines. More randomized clinical trials are needed to assess drug effects in FMS subgroups.

The Effect of a Novel form of Extended-Release Gabapentin on Pain and Sleep in Fibromyalgia Subjects: An Open-Label Pilot Study

INTRODUCTION

We assessed the efficacy and safety of extended-release gabapentin in a 15-week, open-label, single-arm, single-center study in patients with fibromyalgia (FM).

METHODS

Subjects with documented diagnosis of FM were allowed to participate in the study. We opened enrollment to those who have tried and failed gabapentinoids such as gabapentin or pregabalin due to side effects. Subjects with autoimmune conditions, and or taking opioids for management of their FM pain, were excluded from the study. Subjects were given an extended-release gabapentin starter pack and treated for total of 12 weeks. The primary study endpoint of pain relief was measured using Numeric Pain Rating System (NPRS) scores, and secondary study endpoints were measured with Fibromyalgia Impact Questionnaire (FIQ), Patient's Global Impression of Change (PGIC), and Medical Outcome Sleep questionnaires (MOS).

RESULTS

A total of 34 subjects were enrolled and 29 subjects completed the starter pack (85%). Patients reported significant pain relief on NPRS by end of 4 weeks (P < 0.0001) on NPRS. Subjects also reported similar magnitude of improvements in FM and its impact on daily life by end of 4 weeks on FIQ (P < 0.0001). Survey of MOS showed our subjects reporting improved sleep quantity (on average, 1.2 hours over baseline) with gradual and statistically significant improvement in quality. Improvements in primary and secondary measurements were reflected in PGIC, with significant improvement in patient's impression of FM by week 8.

LIMITATIONS

Small sample size, geographical bias, relatively short duration of treatment, and single-arm study without control group.

CONCLUSIONS

Extended-release gabapentin relieved FM pain symptoms and improved quality-of-life for the FM subjects studied. Subjects reported improvements in both quantity and quality of sleep.

Clinical characteristics and medication uses among fibromyalgia patients newly prescribed amitriptyline, duloxetine, gabapentin, or pregabalin

OBJECTIVE

Fibromyalgia is a common chronic pain disorder with unclear etiology. No definitive treatment is available for fibromyalgia, and treatment with antidepressants or antiepileptics is often used for symptom management.

METHODS

Using US health care utilization data, a large population-based cohort study was conducted to describe clinical characteristics and medication use patterns in patients diagnosed with fibromyalgia who newly started amitriptyline, duloxetine, gabapentin, or pregabalin.

RESULTS

There were 13,404 amitriptyline starters, 18,420 duloxetine starters, 23,268 gabapentin starters, and 19,286 pregabalin starters. The mean age ranged from 48–51 years and 72–84% in each group were women. Back pain was the most frequent comorbidity in all 4 groups (range 48–64%) and hypertension, headache, depression, and sleep disorder were also common. The median daily dose at the start of followup was 25 mg for amitriptyline, 60 mg for duloxetine, 300 mg for gabapentin, and 75 mg for pregabalin, and >60% of patients remained on the same dose throughout the follow up period. Only one-fifth of patients continued the treatment started for ≥1 year. The mean number of different prescription drugs at baseline ranged from 8–10 across the groups. More than one-half of patients took opioids and one-third took benzodiazepines, sleep disorder drugs, and muscle relaxants.

CONCLUSION

Patients who started 1 of the 4 common drugs for fibromyalgia similarly had multiple comorbidities and other fibromyalgia-related medication use, but continued the treatment only for a short time. The dose of the 4 drugs was not increased in most patients during the followup period.

Real-world treatment patterns and opioid use in chronic low back pain patients initiating duloxetine versus standard of care

To describe the use of pain medications in patients with chronic low back pain (CLBP) after initiating duloxetine or standard of care (SOC [muscle relaxants, gabapentin, pregabalin, venlafaxine, and tricyclic antidepressants]) for pain management, pharmacy and medical claims from Surveillance Data, Inc (SDI) Health were analyzed. Adult patients with CLBP who initiated duloxetine or SOC between November 2010 and April 2011 were identified. Treatment initiation was defined as no pill coverage for duloxetine or SOC in the previous 90 days. Included patients had no opioid use in the 90 days before initiation. Propensity score matching was used to select patients with similar baseline demographic and clinical characteristics for duloxetine and SOC cohorts. Compliance with index medication was assessed via medication possession ratio (MPR) and proportion of days covered (PDC) for 6 months after initiation. The proportion of patients receiving opioids and days on opioids after index date were assessed, and regression models were estimated to compare opioid use between cohorts. A total of 766 patients initiated duloxetine and 6,206 patients initiated SOC. After matching, 743 patients were selected for the duloxetine (mean age 57 years; female 74%) and SOC (mean age 57 years; female 75%) cohorts, respectively. Of the duloxetine cohort, 92% started on or below recommended daily dose (≤60 mg). The duloxetine cohort had significantly higher MPR (0.78 versus [vs] 0.60) and PDC (0.50 vs 0.31), were less likely to use opioids (45% vs 61%), and had fewer days on opioids (median 0 vs 7 days) than the SOC cohort (all P < 0.001). After adjusting for demographic and clinical characteristics, the duloxetine cohort initiated opioids later than the SOC cohort (hazard ratio 0.77, 95% confidence interval 0.66–0.89). CLBP patients initiating duloxetine had better compliance with initiated medication and were less likely to use opioids than those initiating SOC.

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.

A review of duloxetine 60 mg once-daily dosing for the management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic osteoarthritis pain and low back pain

BACKGROUND

Duloxetine is a selective dual neuronal serotonin (5-Hydroxytryptamine, 5-HT) and norepinephrine reuptake inhibitor (SSNRI). It is indicated in the United States for treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), and several chronic pain conditions, including management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic osteoarthritis (OA) pain and chronic low back pain (LBP). Its use for antidepressant and anxiolytic actions has been extensively reviewed previously. We here review the evidence for the efficacy of 60 mg once-daily dosing of duloxetine for chronic pain conditions.

METHOD

The literature was searched for clinical trials in humans conducted in the past 10 years involving duloxetine.

RESULTS

There were 199 results in the initial search. Studies not in the English language were excluded. We then included only studies of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain (OA and LBP). Studies of painful symptoms reported in mental health studies were excluded. This resulted in 32 studies. Articles that did not include a 60 mg/day daily dose as a study arm were excluded. This resulted in 30 studies, broken down as follows: 12 for diabetic peripheral neuropathy, 9 for fibromyalgia, 6 for LBP, and 3 for OA pain.

CONCLUSIONS

The studies reviewed report that duloxetine 60 mg once-daily dosing is an effective option for the management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic OA pain and chronic LBP. As these pains are often comorbid with MDD or GAD, duloxetine might possess the pharmacologic properties to be a versatile agent able to address several symptoms in these patients. With adequate attention to FDA prescribing guidance regarding safety and drug-drug interactions, duloxetine 60 mg once-daily dosing appears to be an effective option in the appropriate pain patient population.