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Pregabalin for pain: exploiting regulatory weaknesses

Authors:

Abstract

Pharmaceuticals are responsible for twice the number of fatalities than those occurring on Victorian roads, yet prescriber oversight measures have only recently been promised. Health budget impact and detrimental functioning resultant from sedation by pain medication are other factors demanding of change in policy. The article has twice been submitted to Dept of Health & Human Services via the Minister, bringing attention to the Schedule3 restriction process underway in the UK for pregabalin.
Pregabalin for pain: exploiting regulatory weaknesses
Geoff Kirwood, GDip Clinical Research
Correspondence: gkirwood@deakin.edu.au
‘The bad news is that you will need to take this medication everyday for the rest of your days. The
worse news is that you won’t need many scripts. - palliative care joke.
Introduction
Medicine is focused on Therapeutic Goods
Administration (TGA) or FDA approval of
treatments, in order to enhance the doctor’s
armamentarium. On the other hand, cost
benefit is vitally important to the patient.
Advocacy groups lobbying for Pharmaceutical
Benefit Scheme (PBS) approval of subsidy is
often at a sponsor’s behest. Efficacy is also
paramount to health consumers but
Prescriber Information from the TGA doesn’t
reveal risk benefit metrics of Number Needed
to Treat (NNT) versus Number Needed to
Harm (NNH), relying instead on an exhaustive
list of possible albeit unlikely side-effects.
In Victoria for the six years to 2015,
prescription medications caused 40.2% of
fatal overdoses, illegal drugs 13.8%, and a
combination was responsible for 22% of the
deaths more than triple roadtoll fatalities.
Coroner Jamieson included this data in her
report on one case, finding: “…immediate need
for a real-time prescription monitoring system
to assist doctors in their clinical decision-
making around drug prescribing(1). There
have been 21 such calls over four years, and a
tentative step will soon be taken. The majority
of the dangers, including non-fatal but
nonetheless debilitating side-effects, are not
being addressed. The Australian state of
Victoria is examined, and is typical of
pharmacotoxicology crises internationally.
Advocacy for regulatory control of
prescription analgesics
The announced proposal in April 2016 from
Victorian Health Minister Jill Hennessy to fund
Dept Health & Human Services (DHHS) for
Real-Time Prescription Monitoring to check
on high risk medication, at a minimum
morphine and oxycodone (2), falls short of
tackling the enormity of this problem.
Oxycodone contributed to 53 of 420 overdose
deaths in the year preceding the funding
announcement, and another 7 were
attributed to morphine. The Press Release
stated no more than future intent to address
drugs such as diazepam, which was found in
176 cases (1).
Even if the scope of controls was expanded
sufficiently to reduce fatalities, over-
prescribing of sedatives is rife. Pain
medications have had substantial industry
investment, owing to palliative need and
resultant longterm dependency, often
entailing easier repeat scripts (3). This has
diverted attention and resource from
addressing the conditions causing pain,
according to the Director of Hunter Hospital
Integrated Pain Service (4). The current trend
to de-prescribe opioids is reversing their
popularity a decade ago with doctors, but
harmful alternatives taking their place are
detailed below. Greater diligence needs to be
applied to the approvals given to subsidised
analgesia, and priority transferred onto
supporting specialist pain clinics.
The discourse that follows was submitted to
Minister Hennessy, who referred the concern
to DHHS Chief Officer Drugs and Poisons
Regulation, Dr Anna Peatt. The response
letter is supplementary to this article, and
states that "While I can understand your
concerns about fraud in research, my area has
responsibility for reducing the likelihood of
harm by certain medicines by regulating their
supply, manufacture and use. This drugs and
poisons regulation area does not oversee
research carried out by chemical
manufacturers." The manufacturer’s
deception of PBS Advisory Committee is
noted, but criticism in statistical reviews by
PBS Drug Utilisation Sub-Committee does not
trigger further investigations of extant
approvals. Federal Health Minister Greg
Hunt’s office did not reply to this advocacy.
Background: Profile of the Chronic Pain
patient community
Nociceptive pain is resultant from either
traumatic insult or acute illness, and is
defined as chronic if unresolved for three
months. Other pain is often neuropathic,
arising due to either damaged nerves or
sensory perception, where no primary cause
could be treated affects 8.5% of the
population (5). Poor prevalence data is
available the 2014 National Health survey
lacks detail but 29.9% reported suffering from
musculoskeletal conditions (6) with inherent
chronic joint pain. Lying between these
figures is the commonly used estimate of 1 in
5 Australians, and the average result of two
similar studies done in SA and NSW shows
that 16.6% suffer chronic pain (7). Only 0.7%
of Chronic Pain Australia members suffer from
cancer pain (8).
In a Dutch purposive sample of older persons
surveyed to determine the condition most
impacting Quality of Life (QoL), as measured
by SF-36, those 24% suffering musculoskeletal
conditions reported the greatest impairment
(9). Insurer MBF commissioned a report into
Australia’s financial burden of pain, estimating
$34.3bn (10) of which one third was lost
productivity, and one fifth health costs.
Among seven strategic concerns the study
highlighted the absence of information on
pain in children, only aggregated data on
society’s most vulnerable being available with
1% of pre-teens afflicted by musculoskeletal
disease (6). Another seven recommendations
included more attention to be paid to the
association of chronic pain with
socioeconomic status (10). Pain sufferers
were 3.9 times more likely to be receiving
disability benefits (11). One twelfth of those
who’d retired early (after 45) due to back pain
had no assets, and the remainder had asset
values eleven twelfths below that of those
who’d worked to 64 (12). Twice as many of
Chronic Pain Aust members complained of
pain’s impact upon ability to work, than on
their family life (8).
Losing all hope makes life-saving a priority.
Suicide can be seen as a rational solution to
inescapable pain, for which palliative relief
destroys QoL. Back pain alone elevates this
risk by 13% (13), after adjusting for comorbid
mental illness. Support groups are vital, yet
the majority of carers are dissatisfied with
their involvement by health professionals (8)
and 20% report no inclusion. Focusing on
wellbeing has the potential to restore vitality,
as shown in its significant association with
foot pain improvers over three years (14). A
bias is apparent in this report, in that poor
mental health is falsely attributed to non-
responders (statistically insignificant p=0.08),
reflecting an industry agenda in the
researchers subsequent grant to trial an
antidepressant in this population.
There has been much discussion of marijuana.
The safe, non-psychotropic extract
cannabidiol is in trial in Australia for treating
mood disorders, intractable juvenile epilepsy,
and chemotherapy-induced nausea. Distrust
of naturally produced drugs has been pivotal
to the 36 year wait since positive studies (15).
Regardless of the merit of using instead the
psychotropic THC-rich marijuana for pain
relief, there is comfort in the knowledge that
road safety risk is routinely monitored by
police already. Both illicit dope and sedatives
limit social engagement, thus introducing
isolation as a determinant of poor health.
Policy changes sought
Governance improvements are required
across the board, from drug approvals
through to dispensing controls. To exemplify
pregabalin/Lyrica®, it being of questionable
efficacy against pain when NNT/NNH is
considered. Yet heavily promoted (16), and in
the six months to Sept 2015 Pfizer Australia
sponsored four pain practitioner Education
Events per week (20). It’s prescribed in 25, 75,
150, and 300mg dosages, whereas Oxycodone
is upped incrementally from 5, 10, 15, 20, 30,
40 to 80mg. Titration by doubling is likely to
create sudden onset of side-effects such as
blackout, given that somnolence is a listed
warning.
Top of the list of prescription volume
increases in the last annual PBS statistics
released (17), pregabalin was number eight in
annual cost of $AUD171.5m in third year of
listing - which is considerably more than the
year five $100m envisaged in the re-
application for PBS listing (18). The second
year usage was 58% above projections,
leading to speculation of excessive off-label
prescribing (19). In the top 20 ranked by cost
of government subsidy, it’s the only palliative
medication. All others address disease
pathophysiology.
Governance concerns are raised due to PBS
approval of pregabalin for neuropathic pain
after Pfizer’s application was refused the
previous year, when the only new published
study was a negative (21) finding of no
improvement over amitriptyline for diabetic
neuralgia but worsened side-effects.
Unpublished study 1107 conducted by the
manufacturer Pfizer was also submitted, but
authors’ identities are confidential: There IS
an agreement between Principal Investigators
and the Sponsor (or its agents) that restricts
the PI’s rights to discuss or publish trial
results”, per trial NCT00407745 registration
with NIH. Regardless of this lack of
transparency, newly appointed PBS Advisory
Committee chair Dr Suzanne Hill endorses
trials conducted by the pharmaceutical
industry for their methodological rigour (22).
Pregabalin was blamed in 31 fatalities in 2015
(1) and overseas forensic toxicology reports
similar. Incidence in German cases trebled
between 2010 and 2011 (23), and a
retrospective analysis of Scottish heroin
overdoses found pregabalin and its weaker
predecessor gabapentin in 35% of cases (24).
It is dispensed five times as often as
oxycodone, with substantial loss of QoL
through impaired functionality such as
inability to drive. It is overlooked in the
VicRoads Impaired Driving pamphlet
currently provided for doctor’s surgeries,
however Valium® is noted. That
benzodiazepine family increases risk of crash
leading to hospitalisation fivefold, whereas for
opioids it’s a non-significant difference (25)
against casualties determined to be
unmedicated.
The standard pregabalin starting dose, 75mg
administered twice daily, resulted in a 50%
increase in steering wheel error rate on a
simulator in a small trial (26). This is one
quarter of the maximum recommended dose.
Pfizer reports on the Likeability of pregabalin
in a small number of recreational drug users,
and the “high” from 450mg was equated to
that from 30mg of diazepam/Valium® (27),
the current leading cause of overdose
fatalities. This rough formulae can be applied
to the past quarter of dispensing data, where
prescriptions for 1,234 5mg tabs of diazepam
were written, compared to an adjusted
equivalent of 848 for pregabalin (28). Usage
of the former is on the wane, but the latter’s
popularity is rapidly rising.
Pregabalin and diazepam work the same way
in suppressing neuron activity that alcohol
does, by respectively: enhanced GABA
transport; GABA receptor agonist ie stronger
effect of GABA; and longer effect of GABA on
receptors. This commonality explains the
major side-effect warning of dizziness and
somnolence. Perception is inhibited, including
nociceptive and proprioceptive hence lost
balance.
In systematic reviews of trials for either the
archetypal chronic pain of fibromyalgia or the
commonest pain disability stemming from
lower back, pregabalin doesn’t reduce pain
per se (29, 30). These meta-analyses
contradict that undertaken by the Cochrane
group responsible for Palliative Pain Support
(31), however team member Dawn Carroll’s
employment by Pfizer before publishing casts
doubt on the independence of this evidence.
The report’s Principal Investigator Prof
Andrew Moore was keynote speaker at the
Pfizer sponsored Australian Pain Society 2014
conference, alongside past President and
recipient of the 2006 Pfizer international
visiting professorship in pain medicine
psychologist Stephen Gibson (32) who teaches
that: gabapentinoids [pregabalin and
gabapentin] stabilise nerves (33). Prof Moore
has contracted to Pfizer but declared such
under pseudonym (34), and further
undeclared conflict of interest is apparent in
positive Cochrane review CD011790 for the
anti-depressant Cymbalta® despite journal
correspondence revealing contract to the
manufacturer (35).
Unwitting patients are being put onto this
product due to dichotomous specialisations
for their conditions, being anaesthetists for
pain relief, and either rheumatologists for
musculoskeletal or oncologists for cancer.
Interest in the analgesic and latest party drug,
ketamine shows desire for a stoned trance is
commonplace, but not so in the pain
community (8). Consolidated effort is required
to instead provide a transparent pathway of
care and rehabilitation. Medication costs will
rise exponentially with approvals underway
for newer expensive bio-agents (10), already
comprising two of the three highest grossing
drugs for 2016 - each at a cost of over
$USD2000 per month (36). Policy is urgently
needed so as to improve governance.
Resultant health sector objectives
Canada recognises the cycle of disability and
worsened illness (38) revealed by differential
outcomes as being a socioeconomic health
determinant, with escalating costs to carers
and inordinate workload burden on
practitioners. Over-reliance on medications
leads to worsened consequence such as
substance abuse risk, whereas behavioural
approaches such as physiotherapy focus on
improved functionality (10). There is an
urgent requirement to determine cost-
effectiveness of care (39), so as to enable
more universal access to affordable
treatments. It has been proposed that
multidisciplinary pain clinics offer best value
for the health dollar (40), whereas over
prescription of opioids reflects a cheaper
interim answer (41).
Encouragement of activity would immediately
improve the ambulatory proportion of back
pain patients, addressing the exponential
increase in transport cost of 129% for a
condition whose prevalence increased 29%
over the same period (42). The question of
weight gain resultant from medication is of
concern. Initially developed as an
anticonvulsant, pregabalin in an epileptic
population increased BMI 0.9 on an average
dose of 300mg and, after up-titration for
seizure control, a 1.4 increase on 380mg (43).
This will detrimentally impact activity. A
Patient Reported Outcome site shows that
18% of users complained of weight gain, and
the majority suffered side-effects severe to
moderately (44).
Meta-analysis of back pain guidelines recently
published argue that the rate of imaging is
currently overused at one in eight back pain
cases (45), unless cancer or an infection is
suspected. Physical therapy should precede
costly CTs or MRIs. The UK consensus
guidance is to offer medication foremost, and
referral to Pain Clinic only if severely affected
(46). However, the limitation of
pharmacotherapy is shown by systematic
review determining a Number Needed to
Treat of > 6 for the halving of neuropathic
pain (47), that is to say at least five leave the
physician without substantial benefit for each
one alleviated.
Pregabalin’s cost-effectiveness study has been
provided by Pfizer, but the conclusion only
offers comparisons against their other
product gabapentin/Neurontin® and the
competitor’s Cymbalta® (48). The hindering
complexity of a multiplicity of measures
including Quality Adjusted Life Years, lost
work days, and direct costs indicates the need
for homogeneity in pharmacoeconomic
reports. An optimal protocol for a community
pain clinic is described (49) but financial
modelling of longterm outcomes will take
another decade.
Recommendations
In accordance with preceding arguments, the
following are sought:
1. That Health Minister Hennessy
expand the scope of the imminent
DHHS prescription monitoring scheme
to include all analgesia previously
shown to have potential for fatal
overdose.
2. That Federal Health Minister Hunt
establish a review into the extant
approval for subsidy of pregabalin on
the PBS.
3. That NHMRC funding be made
available for a study to be undertaken
into sedative doses and equivalent
blood-alcohol levels w.r.t. driving
ability impairment for the purposes of
informative labelling.
4. That a working group comprising
representatives of ANZCA, RACGP and
RACP, and patients be established for
audit of existing Pain Clinics, with
aims of capturing tracking &
performance data and improving
carer collaboration through best
practice.
Affiliation declaration: The author is a
member of Chronic Pain Australia, but does
not act in any official capacity.
References
1. Finding into Death Without Inquest:
Hearing before the Coroner Audrey Jamieson,
Coroners Court(2016).
2. Real-Time Prescription Monitoring
Will Save Lives [press release]. 2016.
3. PBS. Access to medicines for palliative
care on the PBS 2016 [Available from:
http://www.pbs.gov.au/info/publication/facts
heets/palliative-care.
4. Hayes DC. Changing the System.
YouTube2012.
5. Pollack A, Harrison C, Henderson J,
Britt H. Neuropathic pain. Australian Family
Physician. 2013;42:91-.
6. ABS. 4364.0.55.001 - National Health
Survey: First Results, 2014-152015 25 Mar
2017. Available from:
http://www.abs.gov.au/AUSSTATS/abs@.nsf/
DetailsPage/4364.0.55.0012014-
15?OpenDocument.
7. Currow DC, Agar M, Plummer JL, Blyth
FM, Abernethy AP. Chronic pain in South
Australia - population levels that interfere
extremely with activities of daily living.
Australian and New Zealand journal of public
health. 2010;34(3):232-9.
8. Nielsen M. Living with Pain Snapshot
Survey Report2015. Available from:
http://chronicpainaustralia.org.au/images/Sn
apshot_2014_report.pdf.
9. Sprangers MA, de Regt EB, Andries F,
van Agt HM, Bijl RV, de Boer JB, et al. Which
chronic conditions are associated with better
or poorer quality of life? J Clin Epidemiol.
2000;53(9):895-907.
10. AccessEconomics, Limited AEP,
Foundation M, Institute UoSPMR, Research
UoSPM. The High Price of Pain: The Economic
Impact of Persistent Pain in Australia: MBF
Foundation; 2007.
11. Blyth FM, March LM, Brnabic AJ, Jorm
LR, Williamson M, Cousins MJ. Chronic pain in
Australia: a prevalence study. Pain. 2001;89(2-
3):127-34.
12. Schofield DJ, Shrestha RN, Percival R,
Callander EJ, Kelly SJ, Passey ME. Early
retirement and the financial assets of
individuals with back problems. European
Spine Journal. 2011;20(5):731-6.
13. Ilgen MA, Kleinberg F, Ignacio RV, et
al. Noncancer pain conditions and risk of
suicide. JAMA Psychiatry. 2013;70(7):692-7.
14. Butterworth PA, Urquhart DM,
Cicuttini FM, Menz HB, Strauss BJ, Proietto J,
et al. Relationship between mental health and
foot pain. Arthritis care & research.
2014;66(8):1241-5.
15. Cunha JM, Carlini Ea, Pereira AE,
Ramos OL, Pimentel C, Gagliardi R, et al.
Chronic administration of cannabidiol to
healthy volunteers and epileptic patients.
Pharmacology. 1980;21(3):175-85.
16. Smith M, Moore B. Weekly dose:
Lyrica, the epilepsy drug that treats chronic
nerve pain 2016 [Available from:
https://theconversation.com/weekly-dose-
lyrica-the-epilepsy-drug-that-treats-chronic-
nerve-pain-56130.
17. Thomas G, Marlton P. Expenditure
and Prescriptions Twelve Months to 30 June
2016. In: Section PIM, editor. PBS
Statistics2016.
18. PBS. Pregabalin, capsules, 25 mg, 75
mg, 150 mg and 300 mg, Lyrica® - March 2012
2012 [Available from:
http://www.pbs.gov.au/info/industry/listing/
elements/pbac-meetings/psd/2012-
03/pregabalin.
19. Etherton-Beer C. Pregabalin: 24
month predicted versus actual analysis. PBS
Drug Utilisation Sub-Committee; 2015.
20. Pfizer. Member Company Reports.
2015.
21. Boyle J, Eriksson MEV, Gribble L,
Gouni R, Johnsen S, editors. Randomised,
placebo-controlled comparison of
Amitriptyline, Duloxetine and Pregabalin in
Patients with Chronic Diabetic Peripheral
Neuropathic Pain:- Impact on Pain,
Polysomnographic Sleep, Daytime Functioning
and Quality of Life2012.
22. Freemantle N, Hill S. Evaluating
pharmaceuticals for health policy and
reimbursement: Malden, Mass. : BMJ
Books/Blackwell Pub., 2004.; 2004.
23. Lottner-Nau S, Sachs H, Roider G,
Graw M. Abuse of pregabalin - results of the
postmortem toxicology from 2010 to 2012.
Toxichem Krimtech. 2013;2013(80):339.
24. Spence D. Bad medicine: gabapentin
and pregabalin. BMJ : British Medical Journal.
2013;347.
25. Meuleners LB, Duke J, Lee AH,
Palamara P, Hildebrand J, Ng JQ. Psychoactive
Medications and Crash Involvement Requiring
Hospitalization for Older Drivers: A
Population-Based Study. Journal of the
American Geriatrics Society. 2011;59(9):1575-
80.
26. Tujii T, Kyaw WT, Iwaki H, Nishikawa
N, Nagai M, Kubo M, et al. Evaluation of the
effect of pregabalin on simulated driving
ability using a driving simulator in healthy
male volunteers. International Journal of
General Medicine. 2014;7:103-8.
27. Pfizer. Highlights of prescribing
information: Lyrica 2013 [Available from:
http://labeling.pfizer.com/ShowLabeling.aspx
?id=561.
28. Pharmaceutical Benefits Schedule
Item Reports [Internet]. 2017. Available from:
http://medicarestatistics.humanservices.gov.a
u/statistics/pbs_item.jsp.
29. Mathieson S, Maher CG, McLachlan
AJ, Latimer J, Koes BW, Hancock MJ, et al.
Trial of Pregabalin for Acute and Chronic
Sciatica. New England Journal of Medicine.
2017;376(12):1111-20.
30. Üçeyler N, Sommer C, Walitt B,
Häuser W. Anticonvulsants for fibromyalgia.
Cochrane Database of Systematic Reviews.
2013(10).
31. Wiffen P, Collins S, McQuay H, Carroll
D, Jadad A, Moore A. Anticonvulsant drugs for
acute and chronic pain. Cochrane Database
Syst Rev. 2005(3):Cd001133.
32. APS. Keynote Speakers. 2014.
33. ANZCA. Old drugs offer new uses for
pain relief 2012 [Available from:
http://www.anzca.edu.au/documents/old-
drugs-offer-new-uses-for-pain-relief-media-
rel.
34. Andrew R, Derry S, Taylor RS, Straube
S, Phillips CJ. The Costs and Consequences of
Adequately Managed Chronic Non-Cancer
Pain and Chronic Neuropathic Pain. Pain
Practice. 2014;14(1):79-94.
35. Spence D. Bad medicine: the rise of
duloxetine. BMJ : British Medical Journal.
2014;348.
36. InternationalFederationofHealthPlans.
Comparative Price Report 2015 [Available
from:
http://static1.squarespace.com/static/518a3c
fee4b0a77d03a62c98/t/57d3ca9529687f1a25
7e9e26/1473497751062/2015+Comparative+
Price+Report+09.09.16.pdf.
37. Chang DS, Hsu E, Hottinger DG, Cohen
SP. Anti-nerve growth factor in pain
management: current evidence. Journal of
Pain Research. 2016;9:373-83.
38. Health NCCfDo. Policy Approaches to
Reducing Health Inequalities. In: Canada
PHAo, editor. 2016.
39. Rubinstein SM, van Middelkoop M,
Assendelft WJJ, de Boer MR, van Tulder MW.
Spinal manipulative therapy for chronic low-
back pain. Cochrane Database of Systematic
Reviews. 2011(2).
40. Gatchel RJ, Okifuji A. Evidence-based
scientific data documenting the treatment
and cost-effectiveness of comprehensive pain
programs for chronic nonmalignant pain. The
journal of pain : official journal of the
American Pain Society. 2006;7(11):779-93.
41. Schatman ME, Webster LR. The health
insurance industry: perpetuating the opioid
crisis through policies of cost-containment
and profitability. J Pain Res. 2015;8:153-8.
42. Smith M, Davis MA, Stano M, Whedon
JM. Aging baby boomers and the rising cost of
chronic back pain: secular trend analysis of
longitudinal Medical Expenditures Panel
Survey data for years 2000 to 2007. Journal of
manipulative and physiological therapeutics.
2013;36(1):2-11.
43. Hoppe C, Rademacher M, Hoffmann
JM, Schmidt D, Elger CE. Bodyweight gain
under pregabalin therapy in epilepsy:
Mitigation by counseling patients? Seizure -
European Journal of Epilepsy.17(4):327-32.
44. PatientsLikeMe. Pregabalin treatment
report 2017 [Available from:
https://www.patientslikeme.com/treatments/
show/224#overview.
45. Maher C, Underwood M, Buchbinder
R. Non-specific low back pain. The Lancet.
2016;389(10070):736-47.
46. NICE. Neuropathic pain in adults:
pharmacological management in non-
specialist settings 2017 [Available from:
https://www.nice.org.uk/guidance/cg173/cha
pter/1-Recommendations#treatment.
47. Finnerup NB, Attal N, Haroutounian S,
McNicol E, Baron R, Dworkin RH, et al.
Pharmacotherapy for neuropathic pain in
adults: a systematic review and meta-analysis.
The Lancet Neurology. 2015;14(2):162-73.
48. Parker L, Huelin R, Khankhel Z, Wasiak
R, Mould J. A systematic review of
pharmacoeconomic studies for pregabalin.
Pain practice : the official journal of World
Institute of Pain. 2015;15(1):82-94.
49. AlAujan S, AlMazrou S, Knaggs RD,
Elliott RA. Describing the characteristics,
treatment pathways, outcomes, and costs of
people with persistent noncancer pain
managed by community pain clinics and
generating an indicative estimate of cost-
effectiveness: feasibility study protocol.
Journal of Multidisciplinary Healthcare.
2016;9:237-45.
ResearchGate has not been able to resolve any citations for this publication.
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Neuropathic pain (NP) may result from a lesion, disease or dysfunction of the somatosensory system (peripheral or central nervous system). Examples include diabetic polyneuropathy, postherpetic and trigeminal neuralgias, spinal cord injury pain and painful radiculopathy. While general population surveys in the United Kingdom and France indicate a prevalence of 7-8%, information is scant in Australia, as the existence of NP may be subsumed within the diagnostic label of the associated condition.
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Background: Fibromyalgia (FM) is a clinically well-defined chronic condition of unknown aetiology characterised by chronic widespread pain that often co-exists with sleep problems and fatigue. People often report high disability levels and poor health-related quality of life (HRQoL). Drug therapy focuses on reducing key symptoms and disability, and improving HRQoL. Anticonvulsants (antiepileptic drugs) are drugs frequently used for the treatment of chronic pain syndromes. Objectives: To assess the benefits and harms of anticonvulsants for treating FM symptoms. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 8, 2013), MEDLINE (1966 to August 2013), PsycINFO (1966 to August 2013), SCOPUS (1980 to August 2013) and the reference lists of reviewed articles for published studies and www.clinicaltrials.gov (to August 2013) for unpublished trials. Selection criteria: We selected randomised controlled trials of any formulation of anticonvulsants used for the treatment of people with FM of any age. Data collection and analysis: Two review authors independently extracted the data of all included studies and assessed the risks of bias of the studies. We resolved discrepancies by discussion. Main results: We included eight studies: five with pregabalin and one study each with gabapentin, lacosamide and levetiracetam. A total of 2480 people were included into anticonvulsants groups and 1099 people in placebo groups. The median therapy phase of the studies was 13 weeks. The amount and quality of evidence were insufficient to draw definite conclusions on the efficacy and safety of gabapentin, lacosamide and levetiracetam in FM. The amount and quality of evidence was sufficient to draw definite conclusions on the efficacy and safety of pregabalin in FM. Therefore, we focused on our interpretation of the evidence for pregabalin due to our greater certainty about its effects and its greater relevance to clinical practice. All pregabalin studies had a low risk of bias. Reporting a 50% or greater reduction in pain was more frequent with pregabalin use than with a placebo (risk ratio (RR) 1.59; 95% confidence interval (CI) 1.33 to 1.90; number needed to treat for an additional beneficial outcome (NNTB) 12; 95% CI 9 to 21). The number of people who reported being 'much' or 'very much' improved was higher with pregabalin than with placebo (RR 1.38; 95% CI 1.23 to 1.55; NNTB 9; 95% CI 7 to 15). Pregabalin did not substantially reduce fatigue (SMD -0.17; 95% CI -0.25 to -0.09; 2.7% absolute improvement on a 1 to 50 scale) compared with placebo. Pregabalin had a small benefit over placebo in reducing sleep problems by 6.2% fewer points on a scale of 0 to 100 (standardised mean difference (SMD) -0.35; 95% CI -0.43 to -0.27). The dropout rate due to adverse events was higher with pregabalin use than with placebo use (RR 1.68; 95% CI 1.36 to 2.07; number needed to treat for an additional harmful outcome (NNTH) 13; 95% CI 9 to 23). There was no significant difference in serious adverse events between pregabalin and placebo use (RR 1.03; 95% CI 0.71 to 1.49). Dizziness was reported as an adverse event more frequently with pregabalin use than with placebo use (RR 3.77; 95% CI 3.06 to 4.63; NNTH 4; 95% CI 3 to 5). Authors' conclusions: The anticonvulsant, pregabalin, demonstrated a small benefit over placebo in reducing pain and sleep problems. Pregabalin use was shown not to substantially reduce fatigue compared with placebo. Study dropout rates due to adverse events were higher with pregabalin use compared with placebo. Dizziness was a particularly frequent adverse event seen with pregabalin use. At the time of writing this review, pregabalin is the only anticonvulsant drug approved for treating FM in the US and in 25 other non-European countries. However, pregabalin has not been approved for treating FM in Europe. The amount and quality of evidence were insufficient to draw definite conclusions on the efficacy and safety of gabapentin, lacosamide and levetiracetam in FM.
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"The challenge in all settings is to make the difficult decisions in a way that is defensible, justifiable, ethical, and equitable". So write Nick Freemantle and Suzanne Hill in their introduction to this important discussion on decision making in the reimbursement of pharmaceuticals. Based around a programme supported by the World Health Organization, chapters by leading academics involved in the research tackle such major issues as international pharmaceutical policy, tensions in licensing policies, priority setting, and relationships between the stakeholders. Chapters include. Development of marketing authorisation procedures for pharmaceuticals. Interpreting clinical evidence. International pharmaceutical policy: health creation or wealth creation?. Development of fourth hurdle policies around the world. Economic modelling in drug reimbursement. Priority setting in health care: matching decision criteria with policy objectives. Tensions in licensing and reimbursement decisions: case of riluzole for amytrophic lateral sclerosis. Relationship between stakeholders: managing the war of words. Medicine and the media: good information or misleading hype?. How to promote quality use of cost-effective medicines. Using economic evaluation to inform health policy and reimbursement: making it happen and making it sustainable. Pricing of pharmaceuticals. Evaluating pharmaceuticals for health policy in low and middle income country settings. Besides the controversial issues there is a wealth of practical information including economic modelling and the experiences from the WHO programme, providing readers with workable examples. This is essential reading for clinical researchers in pharmaceuticals and policy makers everywhere.
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Background Sciatica can be disabling, and evidence regarding medical treatments is limited. Pregabalin is effective in the treatment of some types of neuropathic pain. This study examined whether pregabalin may reduce the intensity of sciatica. Methods We conducted a randomized, double-blind, placebo-controlled trial of pregabalin in patients with sciatica. Patients were randomly assigned to receive either pregabalin at a dose of 150 mg per day that was adjusted to a maximum dose of 600 mg per day or matching placebo for up to 8 weeks. The primary outcome was the leg-pain intensity score on a 10-point scale (with 0 indicating no pain and 10 the worst possible pain) at week 8; the leg-pain intensity score was also evaluated at week 52, a secondary time point for the primary outcome. Secondary outcomes included the extent of disability, back-pain intensity, and quality-of-life measures at prespecified time points over the course of 1 year. Results A total of 209 patients underwent randomization, of whom 108 received pregabalin and 101 received placebo; after randomization, 2 patients in the pregabalin group were determined to be ineligible and were excluded from the analyses. At week 8, the mean unadjusted leg-pain intensity score was 3.7 in the pregabalin group and 3.1 in the placebo group (adjusted mean difference, 0.5; 95% confidence interval [CI], −0.2 to 1.2; P=0.19). At week 52, the mean unadjusted leg-pain intensity score was 3.4 in the pregabalin group and 3.0 in the placebo group (adjusted mean difference, 0.3; 95% CI, −0.5 to 1.0; P=0.46). No significant between-group differences were observed with respect to any secondary outcome at either week 8 or week 52. A total of 227 adverse events were reported in the pregabalin group and 124 in the placebo group. Dizziness was more common in the pregabalin group than in the placebo group. Conclusions Treatment with pregabalin did not significantly reduce the intensity of leg pain associated with sciatica and did not significantly improve other outcomes, as compared with placebo, over the course of 8 weeks. The incidence of adverse events was significantly higher in the pregabalin group than in the placebo group. (Funded by the National Health and Medical Research Council of Australia; PRECISE Australian and New Zealand Clinical Trials Registry number, ACTRN12613000530729.)
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New drug treatments, clinical trials, and standards of quality for assessment of evidence justify an update of evidence-based recommendations for the pharmacological treatment of neuropathic pain. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), we revised the Special Interest Group on Neuropathic Pain (NeuPSIG) recommendations for the pharmacotherapy of neuropathic pain based on the results of a systematic review and meta-analysis. Between April, 2013, and January, 2014, NeuPSIG of the International Association for the Study of Pain did a systematic review and meta-analysis of randomised, double-blind studies of oral and topical pharmacotherapy for neuropathic pain, including studies published in peer-reviewed journals since January, 1966, and unpublished trials retrieved from ClinicalTrials.gov and websites of pharmaceutical companies. We used number needed to treat (NNT) for 50% pain relief as a primary measure and assessed publication bias; NNT was calculated with the fixed-effects Mantel-Haenszel method. 229 studies were included in the meta-analysis. Analysis of publication bias suggested a 10% overstatement of treatment effects. Studies published in peer-reviewed journals reported greater effects than did unpublished studies (r(2) 9·3%, p=0·009). Trial outcomes were generally modest: in particular, combined NNTs were 6·4 (95% CI 5·2-8·4) for serotonin-noradrenaline reuptake inhibitors, mainly including duloxetine (nine of 14 studies); 7·7 (6·5-9·4) for pregabalin; 7·2 (5·9-9·21) for gabapentin, including gabapentin extended release and enacarbil; and 10·6 (7·4-19·0) for capsaicin high-concentration patches. NNTs were lower for tricyclic antidepressants, strong opioids, tramadol, and botulinum toxin A, and undetermined for lidocaine patches. Based on GRADE, final quality of evidence was moderate or high for all treatments apart from lidocaine patches; tolerability and safety, and values and preferences were higher for topical drugs; and cost was lower for tricyclic antidepressants and tramadol. These findings permitted a strong recommendation for use and proposal as first-line treatment in neuropathic pain for tricyclic antidepressants, serotonin-noradrenaline reuptake inhibitors, pregabalin, and gabapentin; a weak recommendation for use and proposal as second line for lidocaine patches, capsaicin high-concentration patches, and tramadol; and a weak recommendation for use and proposal as third line for strong opioids and botulinum toxin A. Topical agents and botulinum toxin A are recommended for peripheral neuropathic pain only. Our results support a revision of the NeuPSIG recommendations for the pharmacotherapy of neuropathic pain. Inadequate response to drug treatments constitutes a substantial unmet need in patients with neuropathic pain. Modest efficacy, large placebo responses, heterogeneous diagnostic criteria, and poor phenotypic profiling probably account for moderate trial outcomes and should be taken into account in future studies. NeuPSIG of the International Association for the Study of Pain. Copyright © 2015 Elsevier Ltd. All rights reserved.