Real-world treatment of post-herpetic neuralgia with gabapentin or pregabalin.

BACKGROUND AND OBJECTIVES: There are limited data examining the real-world use of gabapentin and pregabalin for the treatment of post-herpetic neuralgia (PHN). This study examines dosing patterns, therapy outcomes, healthcare utilization and costs of patients with PHN who initiate treatment with gabapentin or pregabalin. METHODS: This was a retrospective administrative claims data analysis from July 2005 to February 2010. Patients with PHN initiating gabapentin or pregabalin (index therapy) from January 2006 to February 2009 were identified and were observed for 12 months after index therapy initiation. Outcomes were mean daily dosages of the index therapy, attainment of minimally effective dosages of gabapentin (≥ 1,800 mg/day) or pregabalin (≥ 150 and ≥ 300 mg/day) persistence, discontinuation, index therapy switching, addition of neuropathic pain medications to index therapy, and healthcare resource use and costs. RESULTS: 1,645 patients were identified. The mean daily dosage was 826 mg for gabapentin and 187 mg for pregabalin. Only 52.6 % of patients initiating gabapentin and 56.9 % initiating pregabalin obtained a refill during the post-index period. Approximately 14 % of patients treated with gabapentin reached the target dosage (1,800 mg/day). For pregabalin, 87 % reached ≥ 150 mg/day and 27 % reached ≥ 300 mg/day. On average, patients took 10 weeks to reach 1,800 mg/day gabapentin, and 5.0 and 9.2 weeks to reach ≥ 150 mg/day and ≥ 300 mg/day pregabalin, respectively. Approximately one-third of patients in both index therapy cohorts added a pain medication; more than half added opioids. The percentage of patients switching from either drug (57 %) or adding a therapy (34 %) were similar between index therapy cohorts; opioids were the most common therapy patients switched to or added. CONCLUSION: It appears that gabapentin and pregabalin are not used effectively to treat PHN. Suboptimal dosing and discontinuation may be associated with supplementary use of other analgesics, especially opioids.

Costs of pregabalin or gabapentin for painful diabetic peripheral neuropathy.

OBJECTIVE: To characterize and compare healthcare resource utilization and costs among patients with painful diabetic peripheral neuropathy (pDPN) newly prescribed pregabalin or gabapentin in a real-world clinical setting. STUDY DESIGN: Retrospective cohort analysis using the MarketScan Commercial Claims and Encounters and Medicare Supplemental Databases (2007-2009). METHODS: Patients with new prescriptions for pregabalin or gabapentin (index event) in 2008 and ≥1 healthcare encounter with an ICD-9 code for pDPN (250.6 or 357.2) within 30 days prior to the first prescription were identified and propensity score matched; continuous enrollment 12 months pre- and post-index was required. Pre- to post-index changes in 12-month all-cause and pDPN-attributable resource utilization and costs were compared between pregabalin and gabapentin using a difference-in-difference (DID) approach. RESULTS: A total of 910 pregabalin patients (48.6% female; mean age 63.3 ± 12.1 years) were matched with 910 gabapentin patients (48.8% female; mean age 63.3 ± 12.1 years). The DID showed no significant differences between cohorts for pre- to post-index changes in any of the all-cause resource utilization categories. While prescription costs increased significantly more with pregabalin (DID -$563; p < 0.0001), the DID of $1603 for total healthcare costs per patient indicated that the pre- to post-index increases of $3081 for pregabalin and $4684 for gabapentin patients were comparable (p = 0.8474). Total pDPN-attributable healthcare costs were significantly higher with pregabalin (DID -$385; p < 0.0001), resulting from higher prescription costs (DID -$432; p < 0.0001). Limitations of this study include the inability to specifically link pDPN with medication prescribing; differences between groups despite propensity score matching; use of proxy measures for adherence parameters; and inability to capture efficacy outcomes. CONCLUSIONS: Among patients initiating pregabalin or gabapentin, there were no significant differences between the drugs in the pre- to post-index changes in all-cause total healthcare costs, despite the increase in prescription costs for pregabalin.

Cost-effectiveness analysis of a new 8% capsaicin patch compared to existing therapies for postherpetic neuralgia.

OBJECTIVE: The purpose of this study was to compare the cost effectiveness of a new 8% capsaicin patch, compared to the current treatments for postherpetic neuralgia (PHN), including tricyclic antidepressants (TCAs), topical lidocaine patches, duloxetine, gabapentin, and pregabalin. METHODS: A 1-year Markov model was constructed for PHN with monthly cycles, including dose titration and management of adverse events. The perspective of the analysis was from a payer perspective, managed-care organization. Clinical trials were used to determine the proportion of patients achieving at least a 30% improvement in PHN pain, the efficacy parameter. The outcome was cost per quality-adjusted life-year (QALY); second-order probabilistic sensitivity analyses were conducted. RESULTS: The effectiveness results indicated that 8% capsaicin patch and topical lidocaine patch were significantly more effective than the oral PHN products. TCAs were least costly and significantly less costly than duloxetine, pregabalin, topical lidocaine patch, 8% capsaicin patch, but not gabapentin. The incremental cost-effectiveness ratio for the 8% capsaicin patch overlapped with the topical lidocaine patch and was within the accepted threshold of cost per QALY gained compared to TCAs, duloxetine, gabapentin, and pregablin. The frequency of the 8% capsaicin patch retreatment assumption significantly impacts its cost-effectiveness results. There are several limitations to this analysis. Since no head-to-head studies were identified, this model used inputs from multiple clinical trials. Also, a last observation carried forward process was assumed to have continued for the duration of the model. Additionally, the trials with duloxetine may have over-predicted its efficacy in PHN. Although a 30% improvement in pain is often an endpoint in clinical trials, some patients may require greater or less improvement in pain to be considered a clinical success. CONCLUSIONS: The effectiveness results demonstrated that 8% capsaicin and topical lidocaine patches had significantly higher effectiveness rates than the oral agents used to treat PHN. In addition, this cost-effectiveness analysis found that the 8% capsaicin patch was similar to topical lidocaine patch and within an accepted cost per QALY gained threshold compared to the oral products.

Treatment choice, duration, and cost in patients with interstitial cystitis and painful bladder syndrome.

INTRODUCTION AND HYPOTHESIS: In order to better understand provider treatment patterns for interstitial cystitis (IC)/painful bladder syndrome, we sought to document the therapies utilized and their associated expenditures using a national dataset. METHODS: A cohort was created by applying the ICD-9 diagnosis of IC (595.1) to INGENIX claims for the year 1999. Subjects were followed for 5 years, and patterns of care and related expenditures were evaluated. RESULTS: Of 553,910 adults insured in 1999, 89 subjects had a diagnosis of IC with 5-year follow-up data. All subjects were treated with oral medication(s), 26% received intravesical treatments, and 22% underwent hydrodistension. Total expenditures per subject were $2,808. CONCLUSIONS: The majority of IC expenditures were attributable to oral medical therapy. Hydrodistension and intravesical instillations were utilized in less than 25% of patients. Hydrodistension was used more frequently among subjects with a new diagnosis; this may reflect its utilization as part of a diagnostic algorithm.

Cost-effectiveness analysis of a lidocaine 5% medicated plaster compared with gabapentin and pregabalin for treating postherpetic neuralgia: a german perspective.

OBJECTIVE: This study set out to assess the cost effectiveness of using a 5% lidocaine (lignocaine) medicated plaster for the treatment of postherpetic neuralgia (PHN) compared with gabapentin, pregabalin 300 mg/day or 600 mg/day in German primary care. The analysis took the perspective of the Statutory Health Insurance scheme (GKV). METHODS: A Markov model was used to calculate the costs (2007) and benefits of the lidocaine plaster, gabapentin 1800 mg/day and pregabalin 300 or 600 mg/day over a 6-month time horizon in elderly patients with PHN who experienced insufficient pain relief with standard analgesics and could not tolerate or had contraindications to tricyclic antidepressants. The model calculated the cost per quality-adjusted life-year (QALY) gained and the cost per additional month without symptoms or intolerable adverse effects. The majority of transition probabilities were obtained from randomized controlled trials identified from a systematic literature review. Further model inputs, including resource use, concomitant medication and long-term efficacy/adherence data, were obtained from a Delphi panel. Utility values were taken from a previous study and age adjusted. Cost data were obtained from official price tariffs. Mortality, indirect costs and costs associated with inpatient treatment were not considered in the present analysis due to the perspective and time horizon employed. RESULTS: Over the 6-month period modelled, the mean total therapy cost per patient treated with the lidocaine plaster was euro911, compared with euro728 for gabapentin, euro875 for pregabalin 300 mg/day and euro977 for pregabalin 600 mg/day. Treatment with the lidocaine plaster was related to greater numbers of QALYs and more months without symptoms or intolerable adverse effects (mean 0.300 QALYs and 4.06 months per patient) than with gabapentin (mean 0.247 QALYs and 2.72 months), pregabalin 300 mg/day (mean 0.253 QALYs and 3.02 months) or pregabalin 600 mg/day (mean 0.256 QALYs and 3.22 months). The lidocaine plaster cost euro3453/QALY gained and euro137 per additional month without adverse effects or symptoms relative to gabapentin and euro766/QALY and euro35 per month without adverse effects or symptoms relative to pregabalin 300 mg/day. The lidocaine plaster dominated pregabalin 600 mg/day, being less costly and more effective. Probabilistic sensitivity analysis indicated that there is a 99.36% chance that the lidocaine plaster is the most clinically effective treatment considered in the analysis and a 99.09% chance that the lidocaine plaster is the most cost-effective treatment of the four therapies considered in the analysis if the GKV is willing to pay at least euro20 000/QALY gained. Extensive deterministic sensitivity analyses demonstrated that the findings are robust. CONCLUSIONS: The 5% lidocaine-medicated plaster is a cost-effective treatment option for the management of PHN in Germany compared with gabapentin and both 300 and 600 mg/day of pregabalin.

[Drugs for postoperative analgesia: routine and new aspects: Part 2: opioids, ketamine and gabapentinoids]. / Medikamente zur postoperativen schmerztherapie: bewährtes und neues : Teil 2: Opioide, ketamin und gabapentinoide.

In part 1 of this review, perioperative aspects of the use of non-opioids (acetaminophene, dipyrone, traditional NSAR, coxibs) were discussed. In part 2 the perioperative aspects of opioids (weak opioids: tramadol, tilidine with naloxone, strong opioids: morphine, piritramide, oxycodone, hydromorphone, fentanyl, methadone, buprenorphine) and coanalgesics (gabapentinoids; ketamine) will now be presented. The main aim of the review is to describe the use, risks and cost of some substances to facilitate the differential indication. New aspects concerning the use of gabapentinoids and ketamine are discussed.

Cost-effectiveness of a lidocaine 5% medicated plaster relative to gabapentin for postherpetic neuralgia in the United Kingdom.

BACKGROUND: Approximately 50% of elderly patients develop postherpetic neuralgia (PHN) after herpes zoster infection (shingles). A lidocaine 5% medicated plaster marketed in the United Kingdom in January 2007 has been shown to be an effective topical treatment for PHN with minimal risk of systemic adverse effects. OBJECTIVE: This paper assessed the cost-effectiveness of using a lidocaine plaster in place of gabapentin in English primary care practice to treat those PHN patients who had insufficient pain relief with standard analgesics and could not tolerate or had contraindications to tricyclic antidepressants (TCAs). The analysis took the perspective of the National Health Service (NHS). METHODS: The costs and benefits of gabapentin and the lidocaine plaster were calculated over a 6-month time horizon using a Markov model. The model structure allowed for differences in costs, utilities, and transition probabilities between the initial 30-day run-in period and maintenance therapy and also accounted for add-in medications and drugs received by patients who discontinued therapy. Most transition probabilities were based on non-head-to-head clinical trials identified through a systematic review. Data on resource utilization, discontinuation rates, and add-in or switch medications were obtained from a Delphi panel; cost data were from official price tariffs. Published utilities were adjusted for age and were supplemented and validated by the Delphi panel. RESULTS: Six months of therapy with the lidocaine plaster cost pound 549 per patient, compared with pound 718 for gabapentin, and generated 0.05 more quality-adjusted life-years (QALYs). The lidocaine plaster therefore dominated gabapentin (95% CI, dominant- pound 2163/QALY gained). Probabilistic sensitivity analysis showed that there was a 90.15% chance that the lidocaine plaster was both less costly and more effective than gabapentin and a 99.99% chance that it cost < pound 20,000/QALY relative to gabapentin. Extensive deterministic sensitivity analyses confirmed the robustness of the conclusions. CONCLUSION: This study found that the lidocaine 5% medicated plaster was a cost-effective alternative to gabapentin for PHN patients who were intolerant to TCAs and in whom analgesics were ineffective, from the perspective of the NHS.

Improving seizure control in dogs with refractory epilepsy using gabapentin as an adjunctive agent.

OBJECTIVE: To assess whether there is a change in seizure activity in dogs with refractory epilepsy that are receiving appropriate doses of phenobarbitone and/or potassium bromide, when gabapentin is added to the therapeutic regimen. DESIGN: A prospective study of 17 dogs with a refractory seizure disorder, 16 of which have idiopathic epilepsy. PROCEDURE: Patients were stabilised using phenobarbitone and/or potassium bromide to produce tolerable therapeutic serum concentrations and dosed additionally with gabapentin at 35 to 50 mg/kg/d (divided twice or three times daily) for 4 months. Owners recorded seizure activity and side effects during this period in a standardised diary. Patients underwent monthly physical examinations and venepuncture to assess selected serum biochemical analytes, as well as phenobarbitone and bromide concentrations. Patients were further monitored for long-term response to adjunctive gabapentin therapy. RESULTS: There was no significant decrease in the number of seizures over the study period for the entire cohort, however three dogs stopped seizuring completely. There was a significant increase in the number of patients who showed an increase in the interictal period (P > 0.001). Serum alkaline phosphatase activity and triglyceride concentrations were elevated at baseline. There were no significant changes in biochemical analytes during the course of the study period. Side effects observed initially on addition of gabapentin included sedation and hind limb ataxia. The former resolved spontaneously after a few days; the latter after a slight reduction in bromide dose. Long-term, a further two patients became seizure free and ten patients remained on gabapentin indefinitely. No long-term side effects have become apparent. CONCLUSION: Addition of gabapentin to phenobarbitone and/or potassium bromide increased the interictal period and shortened the post-seizure recovery in some canine epileptics. In some dogs, seizures were prevented completely, while in others there was an increase in interictal period. The short-half life of gabapentin has advantages for seizure control, however its present high cost may prohibit therapy in large dogs.