European trial results reaffirm efficacy of lidocaine patch 5% (N=263)1,a,b
PHN patients remained on the lidocaine patch 5% more than twice as long as placebo in the 2-week phase (P=0.0398)
Many PHN patients experienced clinically meaningful reductions in painful and extremely painful allodynia at the end of the run-in phase (week 8; n=71) 1,c
a Double-blind, placebo-controlled, parallel-group, multicenter, enriched enrollment, randomized withdrawal (EERW) European study of 263 patients with a mean pain intensity of 5.9 on the 11-point numerical rating scale (NRS). Study comprised 2 phases: an 8-week, open-label, run-in phase in which patients were treated with lidocaine patch 5% only, followed by a randomized, placebo-controlled, double-blind phase of up to 2 weeks’ duration in which patients either continued with lidocaine patch 5% or were switched to treatment with placebo. The primary efficacy endpoint was time-to-exit at the end of the double-blind phase of the trial due to lack of efficacy assessed on an intent-to-treat (ITT) basis. Time-to-exit was defined as the number of days after randomization when patients achieved a ≥2-point decrease in pain relief (6-point verbal rating scale) on 2 consecutive days of therapy, as compared with mean pain relief in the last week on active treatment before randomization. Median times-to-exit in the 14-day placebo controlled phase were 13.5 days with lidocaine patch 5% vs 9.0 days with placebo patch (ITT population, P=0.1510).
b Results of enriched-enrollment studies can’t be generalized to the entire population; subjects in such studies may be able to distinguish the active drug from placebo based on nontherapeutic features of the treatments.
c Percentage of patients with allodynia rated as painful or extremely inful at study enrollment and after 8 weeks of treatment with lidocaine patch 5% in randomized and nonrandomized responder and nonrandomized nonresponder populations of the full analysis set. Allodynia severity was assessed by verbal patient responses according to a categorical scale (0=no pain or discomfort to touch; 1=uncomfortable, but tolerable to touch; 2=painful; and 3=extremely painful, patient cannot stand touching).
To learn more about clinical trials referenced throughout the LIDODERM (lidocaine patch 5%) Web site, click on the titles of the peer-reviewed articles listed below:
Clinical Trial One
Overview
Clinical Trial 1 was a double-blind, balanced-random assignment, vehicle patch (placebo)
controlled, two period cross-over trial of 28 days maximum duration. It was designed
to evaluate the safety and efficacy of LIDODERM compared to vehicle patch in patients
with PHN. The primary outcome assessment was the "time to exit" – the time until
a patient discontinued treatment due to inadequate pain relief. Secondary outcome
measures included patient assessments of the treatment phase that provided the best
pain relief and daily pain relief.
Topical lidocaine relieves postherpetic neuralgia (PHN) more effectively than a vehicle topical patch
Authors
Bradley S. Galer, MD, Michael C. Rowbotham, MD, Jill Perander,
and Erika Friedman.
Clinical Trial Two
Overview
Clinical Trial 2 was a randomized, double-blind study, four-session, 12h, vehicle
patch (placebo) controlled study designed to assess analgesic effects of both drug
and vehicle patch compared to observation only. Primary outcome measures included
patient assessments of pain intensity on a 100-mm visual analog scale (VAS) and
pain relief on a 6-point categorical rating scale.
Test the analgesic efficacy of LIDODERM (lidocaine patch 5%) in reducing pain intensity for allodynic PHN patients versus placebo patch and observation
Authors
Michael C. Rowbotham, MD, Pamela S. Davies, RN MS, Christina Verkempinck, and Bradley
S. Galer, MD.
Clinical Trial One
Topical lidocaine relieves postherpetic neuralgia (PHN) more effectively than a
vehicle topical patch: results of an enriched enrollment study
Patients Preferred LIDODERM vs placebo patch (78% vs 9%)
Authors
Bradley S. Galer, MD, Michael C. Rowbotham, MD, Jill Perander,
and Erika Friedman.
Abstract
This study compared the efficacy of topical lidocaine patches versus
vehicle (placebo) patches applied directly to the painful skin of subjects with
postherpetic neuralgia (PHN) utilizing an 'enriched enrollment' study design. All
subjects had been successfully treated with topical lidocaine patches on a regular
basis for at least 1 month prior to study enrollment. Subjects were enrolled in
a randomized, two-treatment period, vehicle-controlled, cross-over study. The primary
efficacy variable was 'time to exit'; subjects were allowed to exit either treatment
period if their pain relief score decreased by 2 or more categories on a 6-item
Pain Relief Scale for any 2 consecutive days. The median time to exit with the lidocaine
patch phase was greater than 14 days, whereas the vehicle patch exit time was 3.8
days (
P <= 0.001) . At study completion, 25/32 (78.1%) of subjects preferred
the lidocaine patch treatment phase as compared with 3/32 (9.4%) the placebo patch
phase (
P <= 0.001) . No statistical difference was noted between the active and
placebo treatments with regards to side effects. Thus, topical lidocaine patch provides
significantly more pain relief for PHN than does a vehicle patch. Topical lidocaine
patch is a novel therapy for PHN that is effective, does not cause systemic side
effects, and is simple to use. In a randomized, enriched-enrollment, double-blind,
placebo-controlled cross over trial.
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Clinical Trial Two
Lidocaine patch: double-blind controlled study of a new treatment method for postherpetic neuralgia (PHN)
Results: LIDODERM significantly reduced pain intensity from the first application
Authors
Michael C. Rowbotham, MD, Pamela S. Davies, RN MS, Christina Verkempinck, and Bradley S. Galer, MD.
Abstract
Post-herpetic neuralgia (PHN) is a common and often intractable
neuropathic pain syndrome predominantly affecting the elderly. Topical local anesthetics
have shown promise in both uncontrolled and controlled studies. Thirty-five subjects
with established PHN affecting the torso or extremities completed a four-session,
random order, double-blind, vehicle-controlled study of the analgesic effects of
topically applied 5% lidocaine in the form of a non-woven polyethylene adhesive
patch. All subjects had allodynia on examination. Up to 3 patches, covering a maximum
of 420 cm
2, were applied to cover the area of greatest pain as fully as possible.
Lidocaine containing patches were applied in two of the four 12-h-long sessions,
in one session vehicle patches were applied, and one session was a no-treatment
observation session. Lidocaine containing patches significantly reduced pain intensity
at all time points 30 min to 12 h compared to no-treatment observation, and at all
time points 4-12 h compared to vehicle patches. Lidocaine patches were superior
to both no-treatment observation and vehicle patches in averaged category pain relief
scores. The highest blood lidocaine level measured was 0.1 mg/ml, indicating minimal
systemic absorption of lidocaine. Patch application was without systemic side effect
and well tolerated when applied on allodynic skin for 12 h. This study demonstrates
that topical 5% lidocaine in patch form is easy to use and relieves post-herpetic
neuralgia.
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