Efficacy and safety of pregabalin in treatment refractory patients with various neuropathic pain entities in clinical routine

Nonsurgical Approaches to Neuroma Management

Symptomatic neuromas and chronic neuropathic pain are significant problems affecting patients' quality of life and independence that are challenging to treat. These symptoms are due to structural and functional changes that occur peripherally within neuromas, as well as alterations that occur centrally within the brain and spinal cord. A multimodal approach is most effective, with goals to minimize opioid use, to capitalize on the synergistic effects of nonopioid medications and to explore potential benefits of novel adjunctive treatments.

Therapeutic effect of pregabalin on radiotherapy-induced trismus in nasopharyngeal carcinoma patients

AIMS

To evaluate the effect of pregabalin on radiotherapy-induced trismus in patients with nasopharyngeal carcinoma, a hospital-based, clinical retrospective cohort study was conducted.

MATERIALS AND METHODS

Data were collected on patients diagnosed with radiotherapy-induced trismus from March 2014 and March 2016 in the department of neurology in our hospital. Patients in the treatment group were administrated pregabalin for 8 weeks combined with rehabilitation, while the control group only received rehabilitation. The clinical therapeutic effects were observed and evaluated by mandibular motion, severity of trismus measured by late effects of normal tissues/subjective and objective medical analysis (LENT/SOMA) scales, and quality of life (QOL) assessed using the World Health Organization QOL instrument (WHOQOL-BREF) at baseline, week 4 and week 8 during treatment in these two groups, respectively.

RESULTS

In the treatment group, the number of patients with improvement on maximal vertical dimension (MVD) was significantly more than controls at week 4 and week 8 (P=0.013, P=0.004, respectively). Moreover, at week 4 and week 8, the severity of trismus was both significantly improved on LENT/SOMA grade in treatment group (P=0.047, P=0.032, respectively). And at week 8, the physical health and the whole life domain of the WHOQOL-BREF score were significantly increased (P=0.037, P=0.034, respectively). In the treatment group, 11 patients (36.7%) presented dizziness, and 7 patients (23.3%) presented somnolence.

CONCLUSIONS

Administration of pregabalin, in adjunct to rehabilitation, might provide a better outcome in patients with radiotherapy-induced trismus.

The effect of pregabalin treatment on balance and gait in patients with chronic low back pain: a retrospective observational study

Background: Low back pain is the most common musculoskeletal problem, and is a major cause of loss of workforce. Chronic low back pain associated with radiculopathy often includes nociceptive and neuropathic components. While non-steroidal anti-inflammatory drugs are the first choice for the nociceptive component, pregabalin is preferred as the neuropathic component.

Materials and methods: A retrospective analysis was conducted of 48 patients (26 women, 22 men) who had chronic low back pain associated with radiculopathy. A follow-up chart was used to collect data from February 2017 to November 2017. The patients characteristics (age, gender, initial daily dose of pregabalin), neuropathic pain (DN4 scale; Douleur Neuropathique, 4 questions), and balance and gait (Tinetti Balance and Gait Test) were assessed.

Results: The DN4 scores in the fourth (p < .001) and 12th (p < .001) weeks were significantly lower in patients. The Tinetti total test scores (23.2 ± 3.9) in the first (p > .001) week were significantly lower. There was no significant difference between the Tinetti test scores (balance, gait, and total scores) at baseline and in the 12th week (p > .001).

Conclusion: Pregabalin is effective on neuropathic pain and may have adverse effects on balance at initial doses and dose increments. Tolerance develops to these effects at maintenance doses.

Neuropathic Pain and Sleep: A Review

Neuropathic pain is associated with sleep disturbances, and in turn poor sleep quality leads to increased pain sensitivity, so it is essential to assess sleep alongside neuropathic pain. Responses to drugs are inconsistent and identifying the best treatment option that will reduce pain and improve sleep quality remains challenging for clinicians. Anticonvulsants such as pregabalin and gabapentin improve neuropathic pain and have a positive effect on comorbid sleep disturbances. Opioids and antidepressants are effective in reducing pain but can exacerbate sleep disturbances.

FUNDING

Pfizer, Italy.

Injury to skeletal muscle of mice following acute and sub-acute pregabalin exposure

Objective(s):

Pregabalin (PGB) is a new antiepileptic drug that has received FDA approval for patient who suffers from central neuropathic pain, partial seizures, generalized anxiety disorder, fibromyalgia and sleep disorders. This study was undertaken to evaluate the possible adverse effects of PGB on the muscular system of mice.

Materials and Methods:

To evaluate the effect of PGB on skeletal muscle, the animals were exposed to a single dose of 1, 2 or 5 g /kg or daily doses of 20, 40 or 80 mg/kg for 21 days, intraperitoneally (IP). Twaenty-four hr after the last drug administration, all animals were sacrificed. The level of fast-twitch skeletal muscle troponin I and CK-MM activity were evaluated in blood as an indicator of muscle injury. Skeletal muscle pathological findings were also reported as scores ranging from 1 to 3 based on the observed lesion.

Results:

In the acute and sub-acute toxicity assay IP injection of PGB significantly increased the activity and levels of CK-MM and fsTnI compared to the control group. Sub-acute exposure to PGB caused damages that include muscle atrophy, infiltration of inflammatory cells and cell degeneration.

Conclusion:

PGB administration especially in long term care causes muscle atrophy with infiltration of inflammatory cells and cell degeneration. The fsTnI and CK-MM are reliable markers in PGB-related muscle injury. The exact mechanisms behind the muscular damage are unclear and necessitate further investigations.

Efficacy and Safety of Pregabalin for the Treatment of Neuropathic Pain in Patients Undergoing Hemodialysis

OBJECTIVE

Pregabalin is a gamma aminobutyric acid derivative administered for neuropathic pain. It binds to α2δ subunits of voltage-dependent calcium channels, and inhibits calcium inflow of synapses and the release of excitatory neurotransmitters. This study investigated the efficacy and safety of pregabalin in patients with peripheral neuropathic pain undergoing maintenance hemodialysis.

METHODS

This study was a prospective, open-label, single-arm, multi-center trial. Patients were treated with an initial dose of pregabalin at 25 mg; this was then increased up to a maximum of 150 mg depending on the patient during a 12-week study period. Visual Analog Scale, Eight-Item Short Form Health Survey (SF-8), and laboratory data were collected at baseline and the end of the study.

RESULTS

A total of 45 patients with peripheral neuropathic pain were included, of whom 35 patients were analyzed. The final mean dose of pregabalin was 50.7 mg daily. Mean Visual Analog Scale scores significantly decreased from 52.4 mm at baseline to 34.1 mm at the end of the study (p < 0.0001). Scores for all eight categories of the SF-8 significantly increased compared with baseline (p < 0.05). Both physical and mental component summary scores of the SF-8 also significantly increased (p < 0.05). Ten patients were withdrawn from the study because of drowsiness, dizziness, and invalidity; however, no serious adverse drug reactions were recorded.

CONCLUSIONS

If adverse effects are carefully monitored and the administered dosage prudently determined, pregabalin can be an effective treatment for peripheral neuropathic pain in patients undergoing hemodialysis.

TRIAL REGISTRATION

UMIN000023117.

Neuropathic pain in elderly patients with chronic low back painand effects of pregabalin: a preliminary study

STUDY DESIGN

Preliminary study.

PURPOSE

To assess the association of neuropathic pain with chronic low back pain (LBP) and the effect of pregabalin on neuropathic pain in the elderly.

OVERVIEW OF LITERATURE

Of those with chronic LBP, 37% were predominantly presenting with neuropathic pain in young adults. Pregabalin is effective for pain in patients with diabetic neuropathy and peripheral neuralgia. No study has reported on the effects of pregabalin for chronic LBP in elderly patients yet.

METHODS

Pregabalin was administered to 32 patients (age, ≥65 years) with chronic LBP for 4 weeks. Pain and activities of daily living were assessed using the Neuropathic Pain Screening Questionnaire (NePSQ), the pain DETECT questionnaire, visual analog scale, the Japanese Orthopedic Association score, the short form of the McGill Pain Questionnaire and the Roland Morris Disability Questionnaire. Modic change and spinal canal stenosis were investigated using magnetic resonance imaging.

RESULTS

Altogether, 43.3% of patients had neuropathic pain according to the NePSQ and 15.6% patients had pain according to the pain DETECT. The efficacy rate of pregabalin was 73.3%. A significant effect was observed in patients with neuropathic pain after 4 weeks of administration.

CONCLUSIONS

Neuropathic pain was slightly less frequently associated with chronic LBP in the elderly. Pregabalin was effective in reducing pain in patients with chronic LBP accompanied with neuropathic pain. Lumbar spinal stenosis and lower limb symptoms were observed in patients with neuropathic pain. We recommend the use of pregabalin for patients after evaluating a screening score, clinical symptoms and magnetic resonance imaging studies.

From guideline to patient: a review of recent recommendations for pharmacotherapy of painful diabetic neuropathy

Painful diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus, affecting, by some estimates, up to one quarter of diabetic patients. Since 2010, no fewer than 5 major international treatment guidelines for painful DPN have been issued, and there are meaningful differences among them. Duloxetine, pregabalin, gabapentin, and tricyclic antidepressants are the mainstays of treatment, but the choice of which class or agent to use in any given patient should be informed by patient characteristics. This review seeks to describe the differences among the recently issued guidelines, to assess the evidence on which they are based, and to offer insight into the most appropriate treatment choices based on patient characteristics.

Adding pregabalin or gabapentin for the management of community-treated patients with painful diabetic peripheral neuropathy: a comparative cost analysis

BACKGROUND AND OBJECTIVE

Painful diabetic peripheral neuropathy (pDPN) is a highly prevalent complication of diabetes mellitus, which is associated with substantial costs to society and national health systems. This economic impact varies depending on the therapeutic management provided to patients. The objective of this study was to compare healthcare resource utilization and costs among pDPN patients newly treated with pregabalin or gabapentin in routine medical practice.

METHODS

We performed a retrospective medical records study of pDPN patients newly treated with pregabalin or gabapentin as an add-on therapy who are covered by the Badalona Serveis Assistencials (BSA) health plan, a healthcare provider in Spain, from 2006 to 2009. Healthcare resource utilization and days off work were assessed. The societal perspective was used to estimate costs.

RESULTS

Three hundred and ninety-five records were eligible for analysis: 227 (57.5%) included pregabalin and 168 (42.5%) gabapentin. Mean (standard deviation) concomitant use of analgesics throughout the study was higher in the gabapentin cohort [3.9 (2.2) vs. 3.1 (2.1); p < 0.05], mainly due to greater use of non-narcotics (78.0 vs. 71.8%; p < 0.05) and opioids (32.7 vs. 28.6%; p < 0.05). Healthcare costs accounted for 59.2% of total costs, of which 71.9% occurred in primary care, with a mean cost per patient of €2,476 (year 2010 values). Adjusted mean (95% CI) total costs were significantly lower in pregabalin-treated patients [€2,003 (1,427-2,579)] than in gabapentin-treated patients [€3,127 (2,463-3,790)] (p = 0.013), mainly due to lower healthcare costs [€1,312 (1,192-1,432) vs. €1,675 (1,537-1,814); p < 0.001].

CONCLUSIONS

Adding pregabalin to existing pDPN therapy resulted in lower total healthcare costs and lower resource utilization than resulted from adding gabapentin.

Effectiveness of pregabalin as monotherapy or combination therapy for neuropathic pain in patients unresponsive to previous treatments in a Spanish primary care setting

Background and Objective

Patients from a previous study of neuropathic pain (NP) in the Spanish primary care setting still had symptoms despite treatment. Subsequently, patients were treated as prescribed by their physician and followed up for 3 months. Since pregabalin has been shown to be effective in NP, including refractory cases, the objective of this study was to assess the effectiveness of pregabalin therapy in patients with NP refractory to previous treatments.

Methods

This was a post hoc analysis of pregabalin-naïve NP patients treated with pregabalin in a 3-month follow-up observational multicenter study to assess symptoms and satisfaction with treatment. Patients were evaluated with the Douleur Neuropathique en 4 questions (DN4), the Brief Pain Inventory (BPI) and the Treatment Satisfaction for Medication Questionnaire (SATMED-Q) overall satisfaction domain.

Results

1,670 patients (mean age 58 years, 59 % women), previously untreated or treated with ≥1 drug other than pregabalin, were treated with pregabalin (37 % on monotherapy). At 3 months, pain intensity and its interference with activities decreased by half (p < 0.0001), while the number of days with no or mild pain increased by a mean of 4.5 days (p < 0.0001). Treatment satisfaction increased twofold (p < 0.0001). Patients with a shorter history of pain and those with neuralgia and peripheral nerve compression syndrome (PCS) as etiologies had the highest proportion on monotherapy and showed the greatest improvements in pain-related parameters in their respective group categories.

Conclusion

Treatment with pregabalin (as monotherapy or combination therapy) provides benefits in pain and treatment satisfaction in patients with NP, including refractory cases. Shorter disease progression and neuralgia and PCS etiologies are favorable factors for pregabalin treatment response.

Cost analysis of adding pregabalin or gabapentin to the management of community-treated patients with peripheral neuropathic pain

OBJECTIVE

To compare the cost of adding either pregabalin or gabapentin to the management of community-treated patients with peripheral neuropathic pain (PNP).

METHODS

A retrospective observational study was conducted using medical records from a Spanish health care provider claims database. Patients receiving health care for PNP, above 18 years and for which either pregabalin or gabapentin was initiated between 2006 and 2008 were included. Economic evaluation included health care resource utilization costs and costs due to sick leave.

RESULTS

A total of 1163 patients with PNP were eligible for analysis: 764 were prescribed pregabalin and 399 gabapentin in addition to current pain therapy. Mean age was 59.2 years and 62.2% were female. Concomitant use of analgesics was higher in the gabapentin cohort (3.2 vs. 2.7; P = 0.003), mainly due to non-steroidal anti-inflammatory drugs (74.9% vs. 69.5%; P = 0.018) and opioids (27.7% vs. 17.9%; P = 0.031). Adjusted total costs per patient was lower in pregabalin-treated patients (€2514 vs. €3241; P = 0.003), due to less sick leave (€1067 vs. €1633; P = 0.018) and lower health care costs (€1447 vs. €1609; P = 0.004). The higher acquisition cost of pregabalin (€351 vs. €191; P < 0.001) was largely compensated with lower costs in medical visits, physiotherapy, hospital stays and concomitant analgesics.

CONCLUSIONS

In community-treated patients with PNP, total costs were considerably less for those patients initiated with pregabalin therapy than for those patients starting gabapentin add-on therapy. The relatively higher treatment acquisition cost of pregabalin was largely compensated by the overall lower costs for the other components of health care resources and sick leave, thus reducing the economic impact on the health care provider's budget and society.

Post hoc analysis of pregabalin vs. non-pregabalin treatment in patients with cancer-related neuropathic pain: better pain relief, sleep and physical health

BACKGROUND AND PURPOSE

A previous study of cancer-related neuropathic pain (NP) found that a 10-fold increase in pregabalin (PGB) use increased patients' satisfaction with treatment. Further research of PGB vs. non-pregabalin (non-PGB) treatment was carried out to assess if the use of more specific NP-targeting drugs, such as PGB, in combined therapy, in patients with cancer-related NP, provides better health outcomes.

PATIENTS AND METHODS

Post hoc analysis of PGB- vs. non- PGB-treated patients in a 2-month epidemiological, prospective, multicentre study to assess NP prevalence and management in cancer pain patients visiting radiotherapy oncologic units. Patients undertook the Brief Pain Inventory (BPI), Hospital Anxiety and Depression Scale (HADS), the Medical Outcomes Sleep Scale (MOS-Sleep) and the short form (SF-12) Health Survey.

RESULTS

A total of 273 patients with no previous PGB treatment: 162 were treated with PGB polytherapy and 111 with other treatments. At 8 weeks, satisfaction with treatment was 92.6% (PGB) vs. 78.9% (non-PGB), p=0.0024, and benzodiazepine use 37.8% (non-PGB) vs. 19.8% (PGB), p=0.0009. The decreases in BPI total pain intensity and total interference with activities and in MOS overall sleep problems index were significantly larger in the PGB group.

CONCLUSIONS

The addition of more specific NP-targeting drugs to usual treatment, such as PGB, in NP cancer patients provides more satisfaction with treatment and better outcomes in terms of pain intensity, interference with activities and sleep than treatments without specific NP-targeting drugs. Anxiolytic profile of PGB could allow for less use of benzodiazepines.

A cost-utility study of the use of pregabalin added to usual care in refractory neuropathic pain patients in a Swedish setting

OBJECTIVES

Patients refractory to older therapies for neuropathic pain (NeP) have few remaining therapeutic options. This study evaluates the cost-utility of pregabalin in the treatment of patients with refractory neuropathic pain in Sweden, from a healthcare and a societal perspective.

STUDY LIMITATIONS

The use of non-randomized (observational) data to determine the effectiveness of treatments for NeP. The use of non-Swedish data for some input parameters in the model.

METHODS

A previously constructed discrete event simulation model was adapted to compare pregabalin combined with usual care to usual care alone in a Swedish setting. Pain profiles were generated using clinical data from five non-randomized pregabalin studies in refractory NeP patients. Utility data were generated from a UK survey of patients with NeP. Cost data were generated from the Swedish Dental and Pharmaceutical Benefits Board (TLV's) product price database, a national NeP register, and a regional registry study. Indirect costs were estimated from published sources. One-way and probabilistic sensitivity analyses evaluated uncertainty in the model's output.

RESULTS

The incremental cost-effectiveness ratio (ICER) for pregabalin plus usual care treatment compared to usual care was 51,616 SEK/€5364 and 123,993 SEK/€12,886 with and without indirect costs, respectively. One-way sensitivity analyses confirmed the clinical input data as the main driver of the model; even considerable changes to all other input parameters had only a modest effect on the ICER. The ICER remained well below a conservative threshold of 347,495 SEK/€36,113/£30,000 in all scenarios modelled.

CONCLUSIONS

This study found pregabalin combined with usual care to be cost-effective compared to usual care in patients with refractory NeP from a Swedish Health Care perspective. Moreover, sensitivity analysis showed pregabalin's cost-effectiveness to be robust in all scenarios modelled.

A cost-utility study of the use of pregabalin in treatment-refractory neuropathic pain

OBJECTIVES

A small but significant proportion of patients with peripheral neuropathic pain (NeP) are refractory to the typical treatments applied in clinical practice, including amitriptyline and gabapentin. Thus, they continue to suffer the debilitating effects of NeP. This study aimed to evaluate the cost-effectiveness of pregabalin in comparison to usual care, in patients with refractory NeP, from a third party payer's perspective (NHS).

METHODS

A stochastic simulation model was constructed, using clinical data from four non-randomized studies, to generate pain pathways of patients receiving usual care and pregabalin. Treatment effect (pain reduction) was converted to quality-of-life (QoL) data, using a regression analysis based on new utility data, collected from a survey of refractory NeP patients presenting to pain clinics in Cardiff, Wales. All relevant direct costs were estimated using resource use from the survey data (where available) and unit costs from the British National Formulary (BNF). The analysis was run over a 5-year time horizon, with costs and benefits discounted at 3.5%.

STUDY LIMITATIONS

The use of non-randomized (observational) data to characterize the effectiveness of treatments for NeP. Exclusion of productivity costs and consequences from the analysis.

RESULTS

In the base case analysis, an incremental cost-effectiveness ratio (ICER) of £10,803 per quality adjusted life year (QALY) was attained. This result was found to be reasonably insensitive to variations in the key input parameters, with ICERs ranging from £8505 to £22,845 per QALY gained.

CONCLUSIONS

The analysis shows that pregabalin is a cost-effective alternative to usual care in patients with refractory NeP, with an ICER well below the threshold typically adopted by UK health technology assessment groups, such as NICE.

[Prevalence of neuropathic pain according to the NP4 test in primary care]

BACKGROUND

Primary Care Physicians are usually the first to see patients with neuropathic pain. The aim of this study is to assess the prevalence of neuropathic pain, its therapeutic management, and to clinically characterize these patients.

MATERIAL AND METHODS

An epidemiological, observational, cross-sectional study was carried out in Spanish Primary Care settings. The first 25 patients older than 18 years with any type of pain (a total of 16,115) were registered, and the first 5 with a high neuropathic pain component according to the NP4 test, and was clinically confirmed (n= 3,836) were included in the study. Pain intensity and impact on daily activities, as well as overall satisfaction with treatment were assessed.

RESULTS

A total of 45.7% of patients had neuropathic pain according to NP4 test. The median age was 59 years, and 60% were women. Patients took a mean of 2.4 drugs, with NSAIDs (53%) and non-opioid analgesics (51%) being the most common. The scores for Pain intensity and interference in daily activities were both 6.2. The overall opinion of the SATMED-Q test was 47.3/100, which was 1.4 points lower than the standardised score according to Spanish population.

CONCLUSIONS

Neuropathic pain according to NP4 test is highly prevalent in Spanish Primary Care settings. The management of these patients with NSAIDs and non-opioid analgesics is not appropriate, as they are not recommended for this kind of pain. Although they were being treated with more than 2 analgesics, they still referred to high pain intensity, interference in daily activities, and a low general opinion of the treatment.

Pregabalin, the lidocaine plaster and duloxetine in patients with refractory neuropathic pain: a systematic review

BACKGROUND

Patients frequently fail to receive adequate pain relief from, or are intolerant of, first-line therapies prescribed for neuropathic pain (NeP). This refractory chronic pain causes psychological distress and impacts patient quality of life. Published literature for treatment in refractory patients is sparse and often published as conference abstracts only. The aim of this study was to identify published data for three pharmacological treatments: pregabalin, lidocaine plaster, and duloxetine, which are typically used at 2(nd) line or later in UK patients with neuropathic pain.

METHODS

A systematic review of the literature databases MEDLINE, EMBASE and CCTR was carried out and supplemented with extensive conference and grey literature searching. Studies of any design (except single patient case studies) that enrolled adult patients with refractory NeP were included in the review and qualitatively assessed.

RESULTS

Seventeen studies were included in the review: nine of pregabalin, seven of the lidocaine plaster, and one of duloxetine. No head-to-head studies of these treatments were identified. Only six studies included treatments within UK licensed indications and dose ranges. Reported efficacy outcomes were not consistent between studies. Pain scores were most commonly assessed in studies including pregabalin; trials of pregabalin and the lidocaine plaster reported the proportion of responders. Significant improvements in the total, sensory and affective scores of the Short-form McGill Pain Questionnaire, and in function interference, sleep interference and pain associated distress, were associated with pregabalin treatment; limited or no quality of life data were available for the other two interventions. Limitations to the review are the small number of included studies, which are generally small, of poor quality and heterogeneous in patient population and study design.

CONCLUSIONS

Little evidence is available relevant to the treatment of refractory neuropathic pain despite the clinical need. There is a notable lack of high-quality comparative studies. It is evident that there is a need for future, high quality trials, particularly "gold-standard" RCTs in this refractory patient population.

Evaluation of the safety and efficacy of pregabalin in older patients with neuropathic pain: results from a pooled analysis of 11 clinical studies

Background

Older patients are typically underrepresented in clinical trials of medications for chronic pain. A post hoc analysis of multiple clinical studies of pregabalin in patients with painful diabetic peripheral neuropathy (DPN) or postherpetic neuralgia (PHN) was conducted to evaluate the efficacy and safety of pregabalin in older patients.

Methods

Data from 11 double-blind, randomized, placebo-controlled clinical studies of pregabalin in patients with DPN or PHN were pooled. Efficacy outcomes included change in Daily Pain Rating Scale score, ≥30% and ≥50% responders, and endpoint pain score ≤3. Safety was based on adverse events (AEs). Primary efficacy was analyzed by analysis of covariance with terms for treatment, age category, protocol, baseline pain, and treatment-by-age category interaction.

Results

2516 patients (white, n = 2344 [93.2%]; men, n = 1347 [53.5%]; PHN, n = 1003 [39.9%]; pregabalin, n = 1595) were included in the analysis. Patients were grouped by age: 18 to 64 years (n = 1236), 65 to 74 years (n = 766), and ≥75 years (n = 514). Baseline mean pain and sleep interference scores were comparable across treatment and age groups. Significant improvements in endpoint mean pain were observed for all pregabalin dosages versus placebo in all age groups (p ≤ 0.0009), except for the lowest dosage (150 mg/day) in the youngest age group. Clinically meaningful pain relief, defined as ≥30% and ≥50% pain response, was observed in all age groups. The most common AEs were dizziness, somnolence, peripheral edema, asthenia, dry mouth, weight gain, and infections. The relative risks for these AEs increased with pregabalin dose, but did not appear related to older age or type of neuropathic pain.

Conclusions

Pregabalin (150-600 mg/day) significantly reduced pain in older patients (age ≥65 years) with neuropathic pain and improvements in pain were comparable to those observed in younger patients. Titration of pregabalin to the lowest effective dose should allow for effective pain relief while minimizing AEs in older patients with neuropathic pain. Given the common use of polypharmacy in older patients, the absence of known drug-drug interactions makes pregabalin an important treatment option for older patients with pain of neuropathic origin.

A cost-consequence analysis of pregabalin versus usual care in the symptomatic treatment of refractory low back pain: sub-analysis of observational trial data from orthopaedic surgery and rehabilitation clinics

BACKGROUND

low back pain is one of the most common reasons for outpatient consultation in both the primary-care and specialized-care settings. However, few studies have explored the effect of pregabalin in this context.

OBJECTIVE

to prospectively analyse the effect of adding pregabalin on costs and consequences in the treatment of refractory low back pain in routine medical practice.

METHODS

a secondary analysis was carried out in patients aged >or=18 years with a 6-month history of chronic refractory low back pain who had participated in a previous prospective, naturalistic, 12-week, two-visit study (RADIO study). The analysis compared patients receiving pregabalin with those receiving usual care. Severity of pain, healthcare resources utilization, lost workday equivalents due to pain, and related cost-adjusted reductions were assessed. The year of costing for all cost data reported in the study was 2007.

RESULTS

data from a total of 683 patients (49.5% women, mean age 55.0 years), 82.6% of whom were receiving pregabalin, were analysed. Pregabalin was associated with a higher covariable-adjusted reduction in severity of pain, i.e. mean (SD) -3.4 (2.0) compared with -2.0 (2.1) points with usual care on a 10-point neuropathic pain questionnaire (p < 0.001), and a 61.6% response rate (defined as >/=50% reduction in pain from baseline) compared with 37.3% with usual care (p < 0.001). This resulted in fewer lost workday equivalents in the pregabalin group versus usual care (27.8 vs 34.6, p = 0.002), which produced more significant adjusted reductions in indirect costs, i.e. mean (SD) -euro961.8 (euro1242.9) compared with -euro625.8 (euro1169.2) with usual care (p = 0.004). The cost of pregabalin, i.e. mean (SD) euro303.8 (euro175.8) compared with euro37.1 (euro97.0) for usual care (p < 0.001), was offset by larger reductions in the other cost components. While the adjusted total costs were substantially reduced in both groups, pregabalin-treated patients showed more significant reductions, i.e. mean (SD) -euro991.5 (euro1702.3) compared with -euro579.3 (euro2410.3) with usual care (p = 0.023).

CONCLUSION

compared with usual care, addition of pregabalin to existing therapy for refractory low back pain was associated with a larger reduction in pain severity and lost workday equivalents. The acquisition cost of pregabalin was offset by a higher reduction in the indirect components of cost, resulting in a significant decrease in total costs.

A prospective, open-label, multicentre study of pregabalin in the treatment of neuropathic pain in Latin America

AIMS

The objective of this study was to evaluate the safety and efficacy of pregabalin at flexible doses of 150-600 mg/day in Latin American patients with neuropathic pain.

METHODS

A prospective, multicentre, open-label, non-comparative study included patients age >or= 18 years diagnosed with neuropathic pain associated with diabetic peripheral neuropathy, postherpetic neuralgia, chemotherapy-induced peripheral neuropathic pain (PNP), or human immunodeficiency virus-related PNP. Eligible patients (N = 121) had a score of >or= 40 mm on the visual analogue scale and a daily pain rating scale (DPRS) score of >or= 4 throughout screening. Patients received flexible-dose pregabalin (150-600 mg/day) for 12 weeks, which included a 4-week dose-adjustment phase. The primary efficacy measure was change from baseline to end of treatment/last observation carried forward (EOT/LOCF) in weekly mean pain score on the DPRS. Secondary efficacy measures included pain, anxiety, sleep interference, treatment satisfaction and Patient and Clinician Global Impression of Change.

RESULTS

Pregabalin significantly reduced the weekly mean pain score on DPRS from baseline to EOT/LOCF [-3.8 (95% CI: -4.2 to -3.3); p < 0.0001]. Reductions from baseline to EOT/LOCF were observed for all secondary efficacy outcomes (p < 0.0001). Pain and sleep interference were significantly improved compared with baseline across all weeks of the study, as early as 1 week after initiation of pregabalin (p < 0.0001). The most common adverse events (AEs) were somnolence, dizziness, weight gain and peripheral oedema. Nine (7.4%) patients discontinued the study because of AEs and 25 (20.7%) temporarily stopped or reduced their pregabalin dose because of AEs.

CONCLUSIONS

Flexible-dose pregabalin (150-600 mg/day) significantly reduced pain and anxiety and improved sleep and was generally well tolerated in Latin American patients with neuropathic pain.

Pregabalin as mono- or add-on therapy for patients with refractory chronic neuropathic pain: a post-marketing prescription-event monitoring study

This observational study examined the outcome of two different therapeutic strategies in the treatment of chronic neuropathic pain by including pregabalin (PGB) as mono- or add-on therapy in one of two treatment options. Patients with a pain score of > or =4, refractory to usual care for neuropathic pain for at least 6 months, were allocated consecutively to one of two treatment strategies according to the decision of the physician: complete switch to a flexible-dosage, monotherapeutic or add-on therapy with pregabalin (PGB group), or change established doses and combinations of pre-existing mono- or combination therapy without pregabalin (non-PGB group). After 4 weeks (primary endpoint) a significant improvement in pain reduction was documented in both intention-to treat (ITT) analysis (PGB group, n = 85: mean pain score reduction of 3.53, SD 2.03, p < 0.001; non-PGB group, n = 102; mean pain score reduction of 2.83, SD 2.23, p < 0.001) and per-protocol (PP) analysis (PGB group, n = 79: mean pain score reduction 3.53 vs. 2.83, p < 0.05; non-PGB group, n = 81; 3.5 vs. 2.9, p < 0.05) compared to baseline. Comparison of the results observed in the two groups shows that patients in the PGB group achieved significantly greater pain reduction. These results demonstrate that PGB administered twice daily is superior to treatment regimes without PGB in reducing pain and pain-related interference in quality of life.

Antiepileptic drugs in epilepsy and other disorders--a population-based study of prescriptions

PURPOSE

The aim of the study was to quantify the use of antiepileptic drugs (AEDs) in epilepsy and other indications in a nation-wide population using a prescription database.

MATERIALS AND METHODS

Prescription data of AEDs were collected from the Norwegian Prescription Database for the period 2004-2007, including 5.1 million prescriptions from 144,653 patients, all having at least one prescribed and dispensed AED. Diagnosis-related reimbursement codes were used as indicators for clinical use.

RESULTS

Of the AEDs used, 71% was in epilepsy, 15% in psychiatry, 13% in neuropathic pain, and <1% in migraine, trigeminus neuralgia and cancer adjuvance. The use in epilepsy increased steadily from 7.0 to 7.5 DDDs/1000 inhabitants/day (7%) from 2004 to 2007. The use of AEDs in other indications increased considerably more from 2004 to 2007: Neuropathic pain to 1.40 DDDs/1000 inhabitants/day (360%), psychiatry to 1.59 (200%), and migraine to 0.005 (642%). The prevalence of AED users increased and in 2007 it was 0.97% in epilepsy, 0.8% in neuropathic pain, 0.33% in psychiatry and 0.001% in migraine. In 2007, 49% of the AEDs used in epilepsy were a new drug, carbamazepine, lamotrigine and valproate being most frequently used. New AEDs were used in 96% in migraine prophylaxis, 94% in neuropathic pain, and 64% in psychiatry.

CONCLUSIONS

Based on a nation-wide prescription database, this study quantifies the wide and increasing use of AEDs, in particular the newer drugs.

Rash associated with pregabalin use

OBJECTIVE

To report a case of extensive rash induced by orally administered pregabalin in a patient with neuropathic pain.

CASE SUMMARY

A 35-year-old white female with a diffuse, erythematous, maculopapular rash localized to her back and extremities presented to the preoperative holding area for planned exploratory nerve surgery. Prior to presentation, she had been receiving oral pregabalin 50 mg 3 times a day for approximately 2 weeks to treat her neuropathy. Prior to pregabalin therapy, the patient indicated that she had taken gabapentin for approximately 3 weeks for the pain, but had discontinued it due to adverse effects and perceived lack of efficacy. Pregabalin was discontinued and diphenhydramine and methylprednisolone were given to treat the rash. The rash almost completely resolved one week after pregabalin was discontinued.

DISCUSSION

Pregabalin-induced rash was rarely reported in Phase 3 trials, and a clinical description of such events has not been published. Pregabalin exhibits pharmacokinetics different from those of most other antiepileptic agents. Presently, there are no clear mechanisms known for rash associated with pregabalin. The Naranjo probability scale indicates a probable relationship between the development of rash and use of pregabalin by our patient.

CONCLUSIONS

There are currently no other available reports of the development of a rash coinciding with the use of pregabalin. As both Food and Drug Administration-approved and off-label use of this drug increases, further consideration of risk factors associated with the development of rash is needed.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.