Estudio sobre opiáceos vs Biofreeze

1. Targeted Topical Analgesics
For Acute Pain
YVONNE D’ARCY, MS, CRNP, CNS
Pain Management and Palliative Care Nurse Practitioner
Suburban Hospital-Johns Hopkins Medicine
Bethesda, Maryland
Ms. D’Arcy is on the fibromyalgia and chronic pain advisory boards for Pfizer,
and receives book royalties from Springer Publishing.
A
s pressure increases to reduce the use of opioids
in treating pain, prescribers are looking for ways
to treat pain with other types of medications and
interventions, either alone or in combination. One option
is targeted topical analgesics. Some of the most popular
of these medications are nonsteroidal anti-inflammatory
drugs (NSAIDs) in liquid, gel, or patch formulations. The
relatively easy application and the decreased potential for
side effects with topical NSAIDs have made them a more
desirable option when patients present with acute pain.
PAINMEDICINENEWS.COM56
PRINTER-FRIENDLY VERSION AVAILABLE AT PAINMEDICINENEWS.COM
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

2. Increasingly, data are demonstrating that
nonsteroidal gels, creams, and patches applied
topically can provide pain relief for strains and sprains,
and tendinopathies.1
The use of targeted topical
analgesics for surgical pain has been limited in the
past, as little research has been conducted studying
their efficacy. In the United States, about 100 million
surgeries are performed annually; 60% are conducted in
ambulatory settings and 80% of patients report pain.2,3
Despite a national focus on improving the quality of
postoperative pain management5
, patients continue to
report unrelieved or undertreated pain. Although the
use of topical analgesics is off-label, data demonstrate
that they can reduce postoperative pain in patients
undergoing prostatectomy and herniorrhaphy, as well
as other conditions such as soft tissue injury and acute
exacerbations of postherpetic neuralgia (PHN).4
Acute pain is a common complaint of patients
presenting to emergency rooms (ERs), primary care
clinics, and emergent care centers. Acute pain is defined
as stemming from tissue injury, surgery, or trauma and
resolves as healing occurs.5
For acute pain that is mild in
intensity, patients often turn to their medicine cabinets
for an over-the-counter (OTC) medication and self-
treat with their favorite home remedy. This may be an
analgesic cream, ice pack, or an OTC oral medication
such as acetaminophen.6
For pain that is more severe,
patients seek help from health care providers.
Because the sources of acute pain can be diverse, it
is difficult to capture its true prevalence, although it is
thought to be quite high. In an ER chart review during
a 7-day period, pain was documented in 61% of 1,665
patient charts; pain was identified as the chief complaint
in 52% of cases.7
Of the 73 million surgeries performed
in 2003, approximately 80% of patients experienced
postoperative pain, with 86% reporting pain that
was moderate, severe, or extreme.8
Untreated or
undertreated acute pain also can result in unanticipated
readmissions. Uncontrolled pain is the most common
reason patients return to the hospital within the first
weeks after surgery.9
In same-day surgery centers,
pain accounts for 36% of all unscheduled admissions
and readmissions, with orthopedic procedures (33%)
the most common surgeries requiring additional pain
management.10
Multimodal pain management is recommended
in the treatment of acute pain. This includes opioids
as well as other classes of medication, ice packs and
wraps, and assistive devices such as slings. Among the
easiest types of medications to use are topical patches,
creams, and gels that contain a local anesthetic or
NSAID. Patients can be instructed to apply these
medications topically several times per day. Because
of their topical application, the mechanism of action of
these products is localized and the incidence of side
effects is minimized. Additionally, the first-pass effect
of oral medications is avoided.
This article will address the pathophysiology of pain
relief with topical analgesics and offer descriptions of
the various compounds that are currently approved by
the FDA. It will not address the use of many OTC drugs,
privately compounded creams or gels, or medications
that are not currently FDA–approved for use in acute
pain in the United States.
Pathophysiology
The discussion of the pathophysiology of pain is
ever evolving. As more is learned about how the body
processes pain, it becomes clear that there are a number
of ways to incorporate medications for pain relief into
the pain-processing pathways. Topical medications
use the skin as a platform for absorption. Because skin
thickness and permeability vary, topical preparations
can show great variation in their ability to penetrate and
provide pain relief.
When a topical analgesic is applied directly to the
skin, it must pass through the stratum corneum, the
flattened layer of keratinocytes protecting the lower
layers of the epidermis. Because of this, the delivery
agent in which the medication is suspended should
have both hydrophilic and hydrophobic elements to
allow for maximum penetration.11,12
Once the topical
medication penetrates the stratum corneum, it can
enter the skin’s dermal and epidermal layers, thereby
gaining access to the cutaneous nociceptors. These
nociceptors include unmyelinated C-nerve fibers
and other nociceptive fibers, along with associated
structural components such as connective tissue and
fibroblasts12
(Figure, see page 4).
Differences Between Topical
and Transdermal Medication
Absorption
• Topical medications act locally, do not
have systemic side effects, and exert their
action mainly at the site of application.
They penetrate the skin by means of pas-
sive diffusion.
• Transdermal medications act by systemic
absorption and the side-effect profile is
comparable to the systemic route. They
do not need to be applied at the site of
the pain.4,12
PAIN ME DICINE NE WS S P E CIAL E DITI ON 57
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

3. It is important to differentiate between topical
and transdermal medication absorption routes (see
differences list). A topical agent will act locally and
the systemic uptake is limited. Peak plasma levels with
topical medication administration range from 0.2% to
8%, with systemic absorption rates of approximately 3%
to 5% of the oral route.13
Transdermal medication such as fentanyl patches
will be absorbed systemically and dispersed
throughout the patient’s body. The side-effect profile
is comparable to the systemic route. Although the 2
delivery types can be confused, they are very different
and are designed for entirely different drug delivery
systems (see differences list).
Candidates for Targeted Topical Medications
The advantages of using a targeted topical agent for
acute pain are numerous, chief among them are that
patients like creams and gels. Patients are accustomed
to using analgesic balms for self-treating minor aches
and pain. These topical medications are not opioids,
which often have side effects such as constipation,
nausea, or sedation. The side-effect profile of topical
agents is generally very benign. Side effects occur in 12%
of patients treated with topical NSAIDs, with the most
common being skin irritation.13
Patients who are candidates for topical pain
medications are numerous, with the caveat that their
pain should be localized with an accessible area for
application of a patch or cream, gel, or liquid.1
Ideal
patient types for using targeted topical agents for
acute pain include:
• Patients with more than one chronic condition, thus
limiting the potential for drug–drug interactions.
• Patients with cardiovascular and gastrointestinal
risk factors that limit the use of oral NSAIDs.
• Patients with renal or hepatic organ dysfunction,
where the metabolism or clearance of oral medica-
tions is affected.
• Older patients, who as a group have greater
potential for drug–drug interactions or adverse
effects (AEs).1
The use of topical medications to treat pain is
increasing. Conditions that are appropriate for topical
analgesic use are becoming more numerous, and
products such as lidocaine patches are commonly used
to treat chronic pain such as that associated with PHN.
However, there are some medications that have been
designed for acute pain, such as the diclofenac patch
(Flector Patch, Pfizer). Currently, topical medications
are being used for acute and postoperative pain, as
well as acute exacerbations of chronic conditions.
Conditions for which targeted topical medications
can be used, either alone or in combination with other
analgesics, are listed here.
Musculoskeletal pain Some of the most common
musculoskeletal pain conditions include acute low
back pain (LBP), simple ankle sprains, myofascial pain,
neck pain, disk degeneration, and osteoarthritis (OA).
Although some of these conditions are chronic, there
are times when acute exacerbations of pain require
additional treatments for pain relief. Adding a topical
agent can help reduce pain with minimal intervention,
providing a safe and effective option for pain control
either alone or in combination with other types of
medications.
ACUTE LOW BACK PAIN
It is estimated that 84% of adults will experience
LBP at some time in their lives.14
LBP is the leading
patient complaint seen by health care providers in
the United States. In a study of 31,044 patients, the
authors concluded that about 50% of their patients
had LBP in any year and that 15% reported frequent
LBP that could last for more than 2 weeks annually.15
With the national LBP treatment guidelines calling
for remaining active and using medications such
as acetaminophen or NSAIDs,16
targeted topical
medications would be an excellent fit either as a
primary or an adjunct analgesic. However, more
research is needed to support the use of interventions
such as lidocaine patches, although they are currently
used off-label and are well tolerated.
In an open-label study of 131 patients with acute/
subacute LBP, short-term chronic LBP, or chronic LBP,
all 3 groups reported that use of a 5% lidocaine patch
resulted in significant reductions in pain intensity.17
Similar findings were reported in a study of 71 patients,
with participants reporting significant improvement
at weeks 2 and 6 as measured by score changes on
the Neuropathic Pain Scale.18
These findings seem to
suggest that the lidocaine patch can reduce LBP in the
acute phase.
There is some evidence to support the use of
capsaicin cream, an OTC preparation derived from
cayenne peppers, to treat LBP. The main mechanism
of action of capsaicin cream is as a counterirritant
thought to decrease the production of substance P and
desensitize nociceptive sensory neurons.12,19
The action
is biphasic with TRPV1 agonist action that increases the
release of substance P from the cutaneous nociceptors
causing neurogenic inflammation, with subsequent
reversal of defunctionalization of nerve endings causing
an inhibition of pain transmission.11
Capsaicin cream is available in 2 strengths (0.025%
and 0.075%) for topical application and must be
applied several times a day for at least 2 weeks to
achieve maximum benefit.6
A 2006 Cochrane review
indicated improved visual analog scale pain scores for
patients with acute back pain using capsaicin cream on
days 3 and 4.19
A pooled analysis of 368 patients with
PAINMEDICINENEWS.COM58
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

4. musculoskeletal pain using 0.025% capsaicin cream
showed a 38% reduction in pain compared with a 25%
decrease in the placebo arm (number needed to treat
[NNT], 8.1).12
Because of the localized irritation, patients who are
using capsaicin cream to treat acute LBP should be
advised to wear gloves when applying the cream and to
not touch other areas of their body, such as the eyes.6
The major AE seen with capsaicin cream is an intense
burning and pain at the application site experienced
by approximately 80% of patients.20
Some patients
find this AE sufficiently distressing to discontinue the
medication.
NECK PAIN
Strong evidence for the use of topical analgesics
for acute neck pain is lacking. Capsaicin cream is
recommended, but again the resultant burning and
Figure. Cross-section of the layers of the skin.
(Meissner’s)
Haircorpuscle Capillaries
shaft
Dermal Sweat
of touch papillae pore
Arteriole Venule Papilla Lamellated (Panician)
of the hair corpuscle
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Papillary muscle
Sebaceous
(oil) gland
Sweat gland duct
Sudoriferous
(sweat) gland
Adipose tissue
Epidermis
Dermis
Subcutaneous
layer
(Hypodermis)
PAIN ME DICINE NE WS S P E CIAL E DITI ON 59
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

5. pain at the application site limits its use.20
If the patient
can tolerate the applications, this AE should lessen
within 1 to 2 weeks.1
SOFT TISSUE INJURIES, SPRAINS, AND STRAINS
Among the many types of soft tissue injuries,
sprains and strains are responsible for more than 30%
of reported injuries in the United States. These injuries
are commonly seen and treated by primary care
practitioners or in ERs. Between 2004 and 2005, soft
tissue injuries of various types were responsible for 18%
of all initial visits to US ERs.21
Other common injuries
such as ankle sprains cause approximately 2 million
patients to seek help annually.21
The diclofenac 1.3% patch is indicated for use in soft
tissue injuries such as strains and sprains. In a study
of 101 patients with minor sports injuries, treatment
with the diclofenac patch provided a 61% reduction
in pain.22
Jousellin23
studied 134 patients with ankle
pain, and found that pain at rest, pain with movement,
and pain with pressure were significantly improved by
day 3 when the patch was used. Overall, data from
multiple studies demonstrated that the diclofenac
patch is superior to placebo. The patch also has proven
to reduce pain and to be well tolerated by the majority
of patients.
Postherpetic Neuralgia
Once a patient has had chickenpox, the varicella virus
is present and lies dormant in the nerve endings, waiting
for a time when the patient is immunocompromised
either through an illness such as cancer or has decreased
immune function through normal aging. Many patients
who develop herpes zoster (HZ, or shingles) experience
pain accompanied by rash, with pain resolving once the
rash heals. The reactivation of the varicella virus into a
painful eruption of blisters that itch and burn is usually
accompanied by a prodromal time period when the
patient feels ill and experiences pain in the dermatome
that will be the site of the eruption.6
About 10% to 18% of patients with HZ, most often
those who experience severe pain during the acute
phase, are likely to develop PHN.24
Once the rash heals,
the affected area can become highly sensitized to
the point where the wearing of clothes or mild touch
are extremely painful. Patients describe this pain as
comparable to the burn of a hot iron touching the skin
or a horribly painful itching.
The intense pain of PHN is thought to be the result
of neuronal changes not only in the periphery as
evidenced by neuronal loss but also atrophy of the
spinal cord dorsal horn.25,26
This pain can last for weeks,
months, or even years and is extremely difficult to treat.
Placing a lidocaine patch over the affected area
once the rash has healed can be effective in reducing
pain. Qutenza (8% capsaicin patch, Acorda), can be
placed over the affected area for 1 hour after a local
anesthetic has been applied to reduce burning. Once
the patch is removed, pain relief can last for up to 12
weeks. Despite the potential severity of pain in the
eruption phase, these patches are only to be applied
over areas of intact skin.
Postoperative Pain
Postoperative pain continues to be problematic
in the United States. Despite efforts and public calls
for change, patients continue to report unrelieved
or undertreated pain after surgery. In a study of 300
surgical patients, 80% reported concern over control of
their postoperative pain.27
Of the inpatient participants,
75% reported moderate, severe, or extreme
postoperative pain, whereas 72% of the outpatients
reported pain at moderate to extreme levels.27
Patients
who experienced high levels of pain before surgery
reported pain levels in the postoperative period to be
greater.
When questioned about medication choices, 57%
of patients in the study preferred non-narcotic pain
medications, although only 30% expressed concerns
about addiction. Although opioids are considered the
mainstay of acute postoperative pain management,
using a multimodal approach with a variety of
medications is currently recommended, making topical
analgesics an option with great potential merit.
Using topical analgesics for postoperative pain is
attractive for several reasons. Opioids cause sedation,
especially in opioid-naive surgical patients, as well
as side effects that delay recovery such as nausea
and vomiting. The use of topical analgesics avoids
adding a medication that potentially results in these
side effects. There is, however, concern over systemic
absorption if the area of pain is open, a wound, or over
surgical incisions, as topical analgesics are limited to
areas of intact skin.
The use of lidocaine patches is considered off-
label in postoperative patients; however, results
from 2 studies have supported their use. In a
prospective, double-blind, placebo-controlled study
with 71 retropubic prostatectomy patients, normal
postoperative analgesic methods such as patient-
controlled analgesia were supplemented with the use
of a 5% lidocaine patch cut in half and placed on both
sides of the surgical incision. Patients in the placebo
group had a sterile gauze placed in the same location
in the same fashion. The study patch and the placebo
gauze were removed after 24 hours. Findings from this
study indicate that the addition of the lidocaine patch
along the surgical incision for 24 hours resulted in
reduced pain. There was also some evidence that the
reduction in pain positively affected mood and ability
to walk and breathe deeply.27
In a second study with 30 patients who underwent
PAINMEDICINENEWS.COM60
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

6. laparoscopic ventral hernia repair, 50% had a 5% lidocaine
patch placed over the area of the underlying mesh,
whereas the other half did not. Results indicated that the
patients in the patch group had a statistically significant
reduction in pain scores at discharge.28
The reduced pain
scores continued out to a 2-week period.
Although the research base is not large, it has been
indicated that the use of a lidocaine patch can reduce
pain in postoperative patients. In future studies, other
patient types can be identified and other techniques
explored.
Medications
A variety of medications have been adapted for use
as targeted topical analgesics. Studies have shown that
using the medications in this way can provide excellent
pain relief. In a meta-analysis of 86 randomized studies
with 10,160 patients with analysis at 1 week for acute
pain, the relative benefit for pain relief was calculated
at 1.7 with an NNT of 3.9.29
Patients in these studies also
reported reduced pain levels compared with placebo,
and none reported a better analgesic benefit with oral
medications compared with topical preparations.30
In a
review of 19 double-blind studies with more than 3,000
patients, the use of topical diclofenac medications
reduced pain and inflammation in the area of the injury.31
Clearly, topical preparations result in satisfactory
analgesic effects.
GELS AND LIQUIDS
The 2 medications that are most commonly used
in the gel and liquid category are diclofenac sodium
1% gel (Voltaren Gel, Endo, Novartis) and diclofenac
sodium topical solution 1.5% w/w dimethyl sulfoxide
(Pennsaid, Mallinckrodt) liquid. Both products are
FDA–approved for use in treating localized pain from
OA. In a comparison study with 24 patients, 40 drops
of Pennsaid and 4 grams of Voltaren gel were applied
to the knee. Ninety percent of patients preferred the
preparation containing dimethyl sulfoxide.31
Patients
perceived a difference in the odor, feel, and stickiness
of the 2 products.
Both medications use the same NSAID, diclofenac,
but in different formulations with different carriers.
There is scant evidence for use in acute pain but there
is good indication for use in OA.32
Pennsaid
Pennsaid consists of diclofenac sodium 1.5%
w/w dimethyl sulfoxide, which is used to enhance
penetration into the skin. To apply the liquid, the
patient dispenses 10 drops at a time, 4 times, into their
hand and places them around the knee front to back,
4 times per day.32
Voltaren Gel
Voltaren gel consists of 1% diclofenac sodium coupled
with isopropyl alcohol, propylene glycol, and water,
which allows for better penetration of the skin layer.32
A dosing card is supplied with the product indicating
2 g for each elbow, and 4 g for each knee, ankle, or foot,
with a maximum daily dose of 32 g.
Studies have found that the use of either topical
diclofenac product can reduce pain and increase
functionality. Baraf et al33
found that patients with
knee OA who used diclofenac 1% gel 4 times daily
reported improved pain relief and better function at
12 weeks compared with patients in the control group.
Herndon34
found that diclofenac solution reduced pain
and enhanced physical functioning at a similar level
as oral diclofenac. Unfortunately, there is a lack of
research on the use of these 2 products for treatment
of acute pain.
PATCHES
The 2 analgesic patches that are most commonly
used are lidocaine 5% topical anesthetic patch and
diclofenac epolamine topical patch 1.3% (Flector
Patch). Both patches have a flannel-type backing over
a medication-infused gel and are covered by a plastic
film. To use the patch, the plastic film is removed and the
patch is then applied over the painful area, medication
side down.
5% Lidocaine Patch
Topical anesthetics such as the 5% lidocaine patch
are thought to relieve pain by leaving skin sensation
intact but blocking ectopic discharges from abnormal
sodium channels in dermal nociceptors.12
The patches
are best used in localized areas of pain.
The 5% lidocaine patch consists of a woven flannel
backing with 5% lidocaine in an adhesive material over
the inner surface. The flannel backing helps control the
release of the medication over the 12-hour application
period, although patients have worn the patch for 24
hours with no ill effects.5
The maximum number of
patches that can be applied at any time is 3. The patch is
simple and easy to use and patients report satisfactory
pain reduction.
In a review of lidocaine patches,35
the use of the
patch versus pregabalin in the settings of PHN and
painful diabetic neuropathy demonstrated similar
levels of pain relief but a greater safety profile with the
patch. Single studies examining the use of lidocaine
patches off-label in a variety of painful neuropathic
conditions such as polyneuropathy indicated that pain
control was effective; however, larger sample sizes and
more studies would help confirm the positive effect of
patch use.
Flector Patch
Flector Patch uses an NSAID, diclofenac epolamine
1.3%, encased in a ready-to-use patch that can be
applied over the site of a sprain, strain, or contusion. The
patch has an outer layer of polyester felt and the inner
adhesive layer contains 1.3% of diclofenac epolamine in
PAIN ME DICINE NE WS S P E CIAL E DITI ON 61
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

7. a polymeric hydrogel.21
The felt backing helps prevent
drying of the hydrogel layer and hydrates the area of
skin covered by the patch. The hydrogel enhances the
absorption of the medication to allow for release over
12 hours.
Multiple studies have shown the effectiveness of
the Flector patch for analgesia and anti-inflammatory
effect. In a multicenter, placebo-controlled study of
ankle sprain treatment with 140 patients, pain scores
at initiation and at 3 and 7 days were significantly
improved when the Flector patch was used compared
with placebo.36
In a study of 222 patients with benign
sports injuries, placebo patches and Flector patches
were placed over the area of the injury. The Flector
patch patients reported significantly better pain relief
even at 14 days.37
The most common AE with the Flector patch was
topical irritation at the application site. In a comparison
study with 22,949 patch applications for the Flector
patch group, pruritus was the most commonly reported
AE (1.6%), followed by erythema (0.6%), application
site reaction (0.3%), and rash (0.3%).30
The risk–benefit
analysis of using the Flector patch points to it being an
effective method of pain relief and inflammation with a
low incidence of AEs.
Concerns for the Older Patient
Topical medications are ideal for older patients who
cannot tolerate opioids or oral NSAIDs. Applying a gel or
liquid over a painful area can help reduce pain to a level
that is tolerable and improve function. The improved
pain relief with reduced AEs is a big selling point for
patients with limited choices for pain medications, such
as the geriatric population.
There are some special concerns that bolster the
arguments for using topical analgesics in the geriatric
patient population. These include the following:
• Reduced fat-to-muscle ratios in this age group
result in a variability of drug levels, making the use
of medications such as opioids less than optimal.
• Reduced renal and hepatic metabolism also can
affect drug clearance in older patients using oral
medications.
• Older patients often are taking a number of med-
ications for various comorbidities, making med-
ications with mild AE profiles like topicals more
appealing.
• Topical analgesics can help reduce the likelihood of
medication interactions as well as provide localized
pain relief.
• The American College of Rheumatology 2012
strongly recommends the use of topical NSAIDs
rather than oral NSAIDs for the management of OA
of the hand, hip, and knee.
• The American Geriatrics Society recommends using
topical analgesics for neuropathic considerations
and using topical lidocaine for localized non-neuro-
pathic pain; patients with localized non-neuropathic
persistent pain also may be candidates for topical
NSAIDs.1
Summary
The future of topical medications is wide open.
There are any number of medications that can be
formulated into a topical product, which would
increase the number of available treatments. As
demand grows for these easy-to-use medications,
more investment in the development of additional
products will be necessary.
There is also an opportunity to develop more potential
dispensing systems to better move the medications into
the dermal layers. Any method to increase the active
period of the medications would improve the usability
of the products.
Overall, topical medications in any form seem to
be well accepted by the patients who use them. Side
effects are low and pain relief is excellent. Increasing
the use of topical analgesics in the acute pain patient
population will only enhance pain relief for those
patients who are now reporting unrelieved pain from
surgery and acute injuries.
References
1. McCarberg B, D’Arcy Y. Options in topical therapies in the
management of patients with acute pain. Postgrad Med. 2013;125
(4 suppl):19-24.
2. Cullen K, Hall M, Golosinsky A. Ambulatory surgery in the United
States. Nat Health Stat Rep. 2009;11:1-25.
3. National Center for Health Statistics. Number of all-listed proce-
dures from discharges from short-stay hospitals by procedure
category and age: United States 2009. Atlanta, GA: Centers for
Disease Control and Prevention.
4. Casale R, Mattia C. Building a diagnostic algorithm on local-
ized neuropathic pain (LNP) and targeted topical treatment:
focus on 5% lidocaine medicated plaster. Ther Clin Risk Manag.
2014;10:259-268.
5. American Pain Society. Principles of Analgesic Use in the Treat-
ment of Acute Pain and Cancer Pain. Sixth Edition. Glenview, IL:
APS; 2008.
6. D’Arcy Y. A Compact Clinical Guide to Acute Pain Management.
New York, NY: Springer Publishing; 2011.
PAINMEDICINENEWS.COM62
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.

8. 7. Cordell W, Keene K, Giles B, et al. The high prevalence of pain in
emergency care. Am J Emerg Med. 2002;20(3):165-169.
8. Apfelbaum J, Chen C, Mehta S, et al. Postoperative pain
experience: results from a national survey suggest postop-
erative pain continues to be undermanaged. Anesth Analg.
2003;97(2):534-540.
9. Palomano R, Dunwoody C, Krenzischeck D, et al. Perspective
on pain management in the 21st century. Pain Manag Nurs.
2008;9(1):S3-S10.
10. Coley K, Williams B, DaPos S, et al. Retrospective evaluation of
unanticipated admissions and readmissions after same day surgery
and associated costs. J Clin Anesth. 2002;14(5):349-353.
11. Zempsky W. Topical analgesics in treating neuropathic and muscu-
loskeletal pain. Pain Medicine News. 2013;11(10):7-10.
12. Stanos S. Topical agents for the management of musculoskeletal
pain. J Pain Symptom Manage. 2007;33(3):342-355.
13. Heyneman C, Lawless-Liday C, Wall G. Oral versus topical NSAIDs
in rheumatic diseases: a comparison. Drugs. 2000;60(3):555-574.
14. Walker B. The prevalence of low back pain: systematic
review of the literature from 1966 to 1998. J Spinal Disord.
2000;13(3):205-217.
15. Deyo R, Mirza S, Martin B. Back pain prevalence and visit rates:
estimates for U.S. national surveys. Spine. 2002;31(23):2724-2727.
16. Chou R, Huffman L. Medications for acute and chronic low back
pain: a review of the evidence for an American Pain Society/Amer-
ican College of Physicians clinical practice guideline. Ann Intern
Med. 2007;147(7):505-514.
17. Gimbel J, Linn R, Hale M, et al. Lidocaine patch treatment in
patients with low back pain: results of an open label non-random-
ized pilot study. Am J Ther. 2005;12(4):311-319.
18. Galer B, Gammaitoni A, Oleka N, et al. Use of the lidocaine patch
5% in reducing intensity of various pain qualities reported by
patients with low back pain. Curr Med Res Opin. 2004;20(suppl
2):S5-S12.
19. Becker J, Stumbo J. Back pain in adults. Prim Care.
2013;40:271-288.
20. Pangarkar S, Lee P. Conservative treatment for neck pain: medica-
tions, physical therapy, and exercise. Phys Med Rehabil Clin N Am.
2011;22:503-520.
21. McCarberg B, Argoff C. Topical diclofenac epolamine patch 1.3%
for treatment of acute pain caused by soft tissue injury. Int J Clin
Pract. 2010;64(11):1546-1533.
22. Jenoure P, Segessar B, Luhti U, et al. A trial with diclofenac HEP
plaster as topical treatment in minor sports injuries. Drugs Exp Clin
Res. 1993;19:125-131.
23. Jousellin E. Flector Tissugel in the treatment of painful ankle
sprain. Traumatol Sport. 2003;20:1S5-1S9.
24. Hampton T. When shingles wanes but the pain does not:
researchers target chronic postherpetic neuralgia. JAMA.
2005;293(20):2459-2460.
25. Oaklander A, Bowsher D, Galer B, et al. Herpes zoster itch:
Preliminary epidemiologic data. J Pain. 2003;4(6):338-343.
26. Oaklander A. Mechanisms of pain and itch caused by herpes zoster
(shingles). J Pain. 2008;9(1 suppl 1):S10-S18.
27. Habib A, Polascik T, Weizer A, et al. Lidocaine patch for postop-
erative analgesia after radical retropubic prostatectomy. Anesth
Analg. 2009;108(6):1950-1958.
28. Saber A, Mohammed H, Elgamal A, et al. Early experience with
lidocaine patch for postoperative pain control after laparoscopic
ventral hernia repair. Int J Surg. 2009;7:36-38.
29. Moore R, Tramer M, Carol D, et al. Quantitative systematic review
of topically applied non-steroidal anti-inflammatory drugs. BMJ.
1998;316(7128):333-338.
30. Kuehl K. Review of the efficacy and tolerability of the diclofenac
epolamine topical patch 1.3% in patients with acute pain due to
soft tissue injuries. Clin Ther. 2010;32:1001-1014.
31. Galer B. A comparative subjective assessment study of Pennsaid
and Voltaren Gel, two topical formulations of diclofenac sodium.
Pain Pract. 2011;11(3):252-260.
32. McPherson M. Cimino N. Topical NSAID formulations. Pain Med.
2013;14:S35-S39.
33. Baraf H, Gold M, Clark M, et al. Safety and efficacy of topical diclof-
enac sodium 1% gel in knee osteoarthritis: a randomized controlled
trial. Phys Sportsmed. 2010;38(2):19-28.
34. Herndon C. Topical delivery of nonsteroidal anti-inflammatory
drugs for osteoarthritis. J Pain Palliat Care. 2012;26:18-23.
35. Mick G, Correa-Illanes G. Topical pain management with 5%
lidocaine medicated plaster-a review. Curr Med Res Opin.
2012;28(6):937-951.
36. Salliant G. Study comparing the efficacy and tolerability of Flector
tissugel to that of placebo in the treatment of benign ankle sprain.
Sports Med. 1998;72:1-5.
37. Galer B. Rowbotham M, Perander J, et al. Topical diclofenac patch
relieves minor sports injury pain: Results from a multicenter con-
trolled clinical trial. J Pain Symptom Manage. 2000;19:287-294.
Suggested Reading
Chang Chien G. Mathur S, Harvey R, Harden N. Topical diclofe-
nac treatment for post-incisional neuropathic pain. Pain Med.
2013;14:950-951.
McCleane G. Topical application of analgesics: a clinical option in day
case anesthesia. Curr Opin Anesthesiol. 2010;23:704-707.
PAIN ME DICINE NE WS S P E CIAL E DITI ON 63
Copyright©
2014
M
cM
ahon
Publishing
G
roup
unless
otherw
ise
noted.
A
llrights
reserved.Reproduction
in
w
hole
orin
partw
ithoutperm
ission
is
prohibited.