carbamates and Postherpetic Neuralgia studies

Research Excerpts

Excerpt	Relevance	Reference
"The efficacy of gabapentin in some patients with postherpetic neuralgia (PHN) may be limited by suboptimal drug exposure from unpredictable and saturable absorption."	9.15	Efficacy of gabapentin enacarbil vs placebo in patients with postherpetic neuralgia and a pharmacokinetic comparison with oral gabapentin. ( Backonja, MM; Canafax, DM; Cundy, KC, 2011)
"Gabapentin, extended-release gabapentin (gabapentin ER), and gabapentin enacarbil (GEn), play an important role in relieving pain associated with postherpetic neuralgia (PHN)."	8.95	Different doses of gabapentin formulations for postherpetic neuralgia: A systematical review and meta-analysis of randomized controlled trials. ( Wang, J; Zhu, Y, 2017)
"The efficacy of gabapentin in some patients with postherpetic neuralgia (PHN) may be limited by suboptimal drug exposure from unpredictable and saturable absorption."	5.15	Efficacy of gabapentin enacarbil vs placebo in patients with postherpetic neuralgia and a pharmacokinetic comparison with oral gabapentin. ( Backonja, MM; Canafax, DM; Cundy, KC, 2011)
"Gabapentin, extended-release gabapentin (gabapentin ER), and gabapentin enacarbil (GEn), play an important role in relieving pain associated with postherpetic neuralgia (PHN)."	4.95	Different doses of gabapentin formulations for postherpetic neuralgia: A systematical review and meta-analysis of randomized controlled trials. ( Wang, J; Zhu, Y, 2017)
" Dizziness was the only treatment-emergent adverse event occurring at ≥10% difference in carisbamate groups versus placebo (study 1: 12% vs."	2.79	Efficacy and safety of carisbamate in patients with diabetic neuropathy or postherpetic neuralgia: results from 3 randomized, double-blind placebo-controlled trials. ( Brashear, HR; DiBernardo, A; Ford, LM; Shi, Y; Smith, T; Todd, MJ, 2014)
" The most commonly reported adverse events were dizziness and somnolence."	2.78	A randomized, double-blind, placebo-controlled trial to assess the efficacy and safety of gabapentin enacarbil in subjects with neuropathic pain associated with postherpetic neuralgia (PXN110748). ( Bell, CF; Chen, C; Freeman, R; Graff, O; Harden, RN; Harding, K; Hunter, S; Kavanagh, S; Laurijssens, B; McClung, C; Rainka, M; Schwartzbach, C; Warren, S; Zhang, L, 2013)

Research

Studies (7)

Authors

Clinical Trials (1)

Trial Overview

Trial Outcomes

Change From Baseline in the Mean 24-hour Average Pain Intensity (API) Score at the Last Week of Each Treatment Period Using Last Observation Carried Forward (LOCF) Data

Timeframe	Studies, this research(%)	All Research%
pre-1990	0 (0.00)	18.7374
1990's	0 (0.00)	18.2507
2000's	0 (0.00)	29.6817
2010's	7 (100.00)	24.3611
2020's	0 (0.00)	2.80

Authors	Studies
Zhang, L	2
Rainka, M	2
Freeman, R	2
Harden, RN	3
Bell, CF	1
Chen, C	2
Graff, O	2
Harding, K	2
Hunter, S	2
Kavanagh, S	2
Laurijssens, B	1
Schwartzbach, C	2
Warren, S	2
McClung, C	2
Smith, T	1
DiBernardo, A	1
Shi, Y	1
Todd, MJ	1
Brashear, HR	1
Ford, LM	1
Kaye, AD	1
Kintanar, T	1
Argoff, CE	1
Bell, C	1
Berges, A	1
Calkins, AM	1
Gudin, J	1
Gidal, B	1
Jaros, MJ	1
Kim, R	1
Shang, G	1
Wang, J	1
Zhu, Y	1
Backonja, MM	1
Canafax, DM	1
Cundy, KC	1

Trial	Phase	Enrollment	Study Type	Start Date	Status
Study PXN110527: The Investigation of the Efficacy and Pharmacokinetics of XP13512 in Subjects With Neuropathic Pain Associated With Post-herpetic Neuralgia (PHN) Who Have Had an Inadequate Response to Gabapentin Treatment.[NCT00617461]	Phase 2	96 participants (Actual)	Interventional	2008-03-31	Completed
[information is prepared from clinicaltrials.gov, extracted Sep-2024]

Baseline and end of treatment values are the calculated means of the daily 24-hour API scores for each participant during the last 7 days prior to randomization (baseline) and the last 7 days on treatment within each period (end of treatment). Participants rated their API over the preceding 24 hours, using an 11-point PI-Numerical Rating Scale (0=no pain, 10=pain as bad as you can imagine). LOCF was used if less than 4 days of diary data were provided. Change from baseline was calculated as end of treatment minus baseline. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean 24-hour Average Pain Intensity (API) Score at the Last Week of Each Treatment Period Using LOCF Data for Each Treatment Period

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-1.18
GEn 3600 mg	-1.47

Baseline and end of treatment values are the calculated means of the daily 24-hour API scores for each participant during the last 7 days prior to randomization (baseline) and the last 7 days on treatment within each period (end of treatment). Participants used a hand-held diary to rate their average pain intensity over the preceding 24 hours, using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). LOCF was used if less than 4 days of diary data were provided. The by period summary is provided as a sensitivity analysis for the primary analysis. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Current (Evening) Pain Intensity Score at the Last Week of Each Treatment Period Using LOCF Data

Intervention	points on a scale (Mean)
GEn 1200 mg in First Intervention Period	-1.11
GEn 3600 mg in First Intervention Period	-1.09
GEn 1200 mg in Second Intervention Period	-1.29
GEn 3600 mg in Second Interevention Period	-1.92

"Current pain is defined as the participant's assessment of pain intensity right now. Participants recorded their current evening pain intensity in the evening before bedtime using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period." (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Current Morning Pain Intensity Score at the Last Week of Each Treatment Period Using LOCF

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-1.10
GEn 3600 mg	-1.39

"Current pain is defined as the participant's assessment of pain intensity right now. Participants recorded their current morning pain intensity in the morning upon wakening using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period." (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Daily Dose in Milligrams of Rescue Medication at the Last Week of Each Treatment Period

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-1.11
GEn 3600 mg	-1.46

Mean daily use of rescue medication (milligrams of acetaminophen) was calculated by determining the average number of tablets taken per day of rescue medication (Commercial Tylenol) during treatment and multiplying that by 500 mg. Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Day-time Average Pain Intensity (API) Score at the Last Week of Each Treatment Period Using LOCF Data

Intervention	milligrams (Least Squares Mean)
GEn 1200 mg	-68.18
GEn 3600 mg	-71.26

Day-time is defined as the time between rising in the morning and going to bed at night. Participants recorded day-time API on a daily basis in the evening before bedtime using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Day-time Worst Pain Intensity Score at the Last Week of Each Treatment Period Using LOCF Data

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-1.17
GEn 3600 mg	-1.48

Day-time worst pain is defined as the participant's assessment of their worst pain intensity between rising in the morning and going to bed at night. Day-time worst pain was recorded in the evening before bedtime using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Night-time Average Pain Intensity (API) Score at the Last Week of Each Treatment Period Using LOCF

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-1.17
GEn 3600 mg	-1.50

Night-time is defined as the time between going to bed in the evening and rising in the morning. Participants recorded night-time API on a daily basis in the morning upon wakening using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Night-time Worst Pain Intensity Score at the Last Week of Each Treatment Period Using LOCF

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-0.92
GEn 3600 mg	-1.21

Night-time worst pain is defined as the participant's assessment of their worst pain intensity between going to bed and rising in the morning. Participants recorded night-time worst pain in the morning upon wakening using an 11-point PI-NRS (0=no pain, 10=pain as bad as you can imagine). Baseline and end of treatment scores are as defined for primary endpoint. Change from baseline = the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Mean Sleep Interference Score at the Last Week of Each Treatment Period Using LOCF Data

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-0.97
GEn 3600 mg	-1.33

Participants assessed sleep interference due to pain on a daily basis using the 11-point NRS (0=pain does not interfere with sleep, 10=pain completely interferes with sleep). Baseline and end of treatment scores are as defined for the primary endpoint. Change from baseline is calculated as the end of treatment score minus the baseline score. An ANCOVA with baseline value, BMI, grouped center as covariates was used. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Number of Participants Who Are Responders on the Clinical Global Impression of Change (CGIC) Questionnaire at the Last Week of Each Treatment Period Presented by Period Using LOCF Data

Intervention	points on a scale (Least Squares Mean)
GEn 1200 mg	-0.97
GEn 3600 mg	-1.23

"The CGIC is a single-item questionnaire designed to provide an overall assessment of treatment from the clinician's perspective since the start of the study. It is measured on a 7-point scale, where 1=very much improved and 7=very much worse. A participant is considered a responder if they have a response of very much improved or much improved. Data are summarized by dose within each treatment period." (NCT00617461)
Timeframe: End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Number of Participants Who Are Responders on the Clinical Global Impression of Change (CGIC) Questionnaire at the Last Week of Each Treatment Period Using LOCF Data

Intervention	participants (Number)
GEn 1200 mg in First Intervention Period	5
GEn 3600 mg in First Intervention Period	8
GEn 1200 mg in Second Intervention Period	10
GEn 3600 mg in Second Intervention Period	10

"The CGIC is a single-item questionnaire designed to provide an overall assessment of treatment from the clinician's perspective since the start of the study. It is measured on a 7-point scale, where 1=very much improved and 7=very much worse. A participant is considered a responder if they have a response of very much improved or much improved. Data are summarized by dose, independent of treatment period." (NCT00617461)
Timeframe: End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Number of Participants Who Are Responders on the Patient Global Impression of Change (PGIC) at the Last Week of Each Treatment Period Using LOCF Data

Intervention	participants (Number)
GEn 1200 mg	15
GEn 3600 mg	18

"The PGIC is a single-item questionnaire designed to provide an overall assessment of treatment from the participant's perspective since the start of the study. It is measured on a 7-point scale, where 1=very much improved and 7=very much worse. A participant is considered a responder if they have a response of very much improved or much improved Data are summarized by dose, independent of treatment period." (NCT00617461)
Timeframe: End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Number of Participants Who Are Responders on the Patient Global Impression of Change (PGIC) Questionnaire at the Last Week of Each Treatment Period Presented by Period Using LOCF Data

Intervention	participants (Number)
GEn 1200 mg	17
GEn 3600 mg	28

"The PGIC is a single-item questionnaire designed to provide an overall assessment of treatment from the participant's perspective since the start of the study. It is measured on a 7-point scale, where 1=very much improved and 7=very much worse. A participant is considered a responder if they have a response of very much improved or much improved. Data are summarized by dose within each treatment period." (NCT00617461)
Timeframe: End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Change From Baseline in the Severity of Pain and the Impact of Pain as Assessed by the Brief Pain Inventory (BPI) at the Last Week of Each Treatment Period Using LOCF

Intervention	participants (Number)
GEn 1200 mg in First Intervention Period	6
GEn 3600 mg in First Intervention Period	11
GEn 1200 mg in Second Intervention Period	11
GEn 3600 mg in Second Intervention Period	17

The BPI assesses the severity and interference of pain; and consists of 6 items assessed on an 11-point NRS (0=no impact to 10=greatest impact). 2 summary scores are calculated: BPI Severity Score (average of first 4 items) and BPI Interference Score (average of 7 responses to item 6); where scores range from 0 to 10 (0=no impact to 10=greatest impact). Analysis of this endpoint is based on the change from baseline (BL) (EOMT score minus the BL score) using an ANCOVA model with BL value, BMI, grouped center as covariates. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of treatment)

Mean Gabapentin Steady-State (ss) Average, Minimum and Maximum Concentrations

Intervention	points on a scale (Least Squares Mean)
	Brief Pain Inventory Severity of Pain	Brief Pain Inventory Interference of Pain
GEn 1200 mg	-1.17	-0.82
GEn 3600 mg	-1.63	-1.57

"Steady-state average (Cave, ss), maximum (Cmax, ss), and minimum (Cmin,ss) plasma concentration of gabapentin in each participant were estimated using the gabapentin plasma concentration data and with the aid of a population pharmacokinetic model. Dispersion is represented by the fifth to ninety-fifth percentile, though labeled as Full Range. A total of 10 blood samples were collected per participant over the Baseline, Period 1, and Period 2 at various timepoints during the dosing interval. Plasma concentration of gabapentin in these samples was measured." (NCT00617461)
Timeframe: A total of 10 blood samples (2 samples at each visit) were collected per participant at Baseline, and the Week 1 and Week 4 visits for each period

Number of Participants Achieving Various Levels of Percent Reduction From Baseline in the Mean 24-hour Average Pain Intensity Score at the Last Week of Each Treatment Period Using LOCF Data

Intervention	micrograms per milliliter (Geometric Mean)
	Cave,ss	Cmin, ss	Cmax, ss
Gabapentin 1800 mg	6.8	4.3	7.4
GEn 1200 mg	4.1	3.0	5.1
GEn 3600 mg	12.4	9.2	15.2

Baseline and end of treatment (EOT) scores are the calculated means of the 24-hour average pain scores for each participant during the last 7 days prior to randomization (Baseline) and the 7 days prior to the last on-treatment completed diary (EOT). Percent reduction from baseline was calculated as the [(EOT score minus baseline score) divided by the baseline score], multiplied by 100. The PI-NRS is an 11-point scale (0=no pain, 10=pain as bad as you can imagine) by which a participant assesses their 24-hour average pain intensity. Data are summarized by dose, independent of treatment period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Number of Participants Achieving Various Levels of Percent Reduction From Baseline in the Mean 24-hour Average Pain Intensity Score at the Last Week of Each Treatment Period Using LOCF Data by Period

Intervention	participants (Number)
	0% or more	10% or more	20% or more	30% or more	40% or more	50% or more	60% or more	70% or more	80% or more	90% or more	100%
GEn 1200 mg	68	51	39	28	17	15	6	4	1	1	0
GEn 3600 mg	71	49	42	32	26	16	11	5	2	2	2

Baseline and end of treatment scores are the calculated means of the 24-hour average pain scores for each participant during the last 7 days prior to randomization (Baseline) and the 7 days prior to the last on-treatment completed diary (end of treatment). Percent reduction from baseline was calculated as the [(end of treatment score minus the baseline score) divided by the baseline score], multiplied by 100. The PI-NRS is an 11-point scale (0=no pain, 10=pain as bad as you can imagine) by which a participant assesses their 24-hour average pain intensity. Data are summarized by period. (NCT00617461)
Timeframe: Baseline and End of Treatment (Weeks 4 and 9, representing the last week of each treatment period)

Article	Year
Evidence-based guidance for the management of postherpetic neuralgia in primary care. Postgraduate medicine, 2013, Volume: 125, Issue:4 Topics: Amines; Analgesics; Capsaicin; Carbamates; Cyclohexanecarboxylic Acids; Evidence-Based Medicine; Gab	2013
Different doses of gabapentin formulations for postherpetic neuralgia: A systematical review and meta-analysis of randomized controlled trials. The Journal of dermatological treatment, 2017, Volume: 28, Issue:1 Topics: Amines; Analgesics; Carbamates; Cyclohexanecarboxylic Acids; Gabapentin; gamma-Aminobutyric Acid; Hu	2017

Article	Year
A randomized, double-blind, placebo-controlled trial to assess the efficacy and safety of gabapentin enacarbil in subjects with neuropathic pain associated with postherpetic neuralgia (PXN110748). The journal of pain, 2013, Volume: 14, Issue:6 Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anesthetics; Carbamates; Dose-Response Relationship, Dru	2013
Efficacy and safety of carisbamate in patients with diabetic neuropathy or postherpetic neuralgia: results from 3 randomized, double-blind placebo-controlled trials. Pain practice : the official journal of World Institute of Pain, 2014, Volume: 14, Issue:4 Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carbamates; Diabetic Neuropathies; Double-Blind Method;	2014
A phase 2a, randomized, crossover trial of gabapentin enacarbil for the treatment of postherpetic neuralgia in gabapentin inadequate responders. Pain medicine (Malden, Mass.), 2013, Volume: 14, Issue:12 Topics: Adult; Aged; Aged, 80 and over; Analgesics; Carbamates; Cross-Over Studies; Dose-Response Relationsh	2013
Impact of Data Imputation Methodology on Pain Assessment over 24 Hours in a Randomized, Placebo-Controlled Study of Gabapentin Enacarbil in Patients with Neuropathic Pain Associated with Postherpetic Neuralgia. Pain medicine (Malden, Mass.), 2016, Volume: 17, Issue:4 Topics: Adult; Analgesics; Carbamates; Double-Blind Method; Female; gamma-Aminobutyric Acid; Humans; Male; M	2016
Efficacy of gabapentin enacarbil vs placebo in patients with postherpetic neuralgia and a pharmacokinetic comparison with oral gabapentin. Pain medicine (Malden, Mass.), 2011, Volume: 12, Issue:7 Topics: Adult; Aged; Amines; Analgesics; Carbamates; Cyclohexanecarboxylic Acids; Double-Blind Method; Femal	2011

carbamates and Postherpetic Neuralgia