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PHARMAC and statins—correction is
needed
Last year Dr. Chris Ellis and Professor Harvey White
discussed past aspects of PHARMAC’s operations relating to the provision
of statins to improve cardiovascular risk. 1 We
made a brief response at the time ( http://www.nzma.org.nz/journal/119-1238/2092/), 2
and we are now providing additional information.
While welcoming different perspectives, a number of comments
were made that PHARMAC considers to be factually incorrect. Our main focus is to
correct these misperceptions, which we do in Table 1 (below). It is important
that PHARMAC does this—not just in terms of responding to criticism, but
because of the important role of statins in the management of cardiovascular
disease in New Zealand.
Evidence underpinning our views is on public record in the
Journal—both for statins2–4 and
wider.5–24 Previous access restrictions
for statins related to their prohibitive prices; simvastatin is now 1/20th the
price of what it was 13 years ago. There is a continual need to balance
priorities in order to maximise health gain across the population.
PHARMAC welcomes close scrutiny of its decisions and
constructive suggestions for improvement. Ongoing improvement in processes and
system—as for all organisations—is critical to best practice and
keeping well-prepared for future challenges. PHARMAC’s recent
consultations on its cost-utility analysis
framework 25 and how best to fund high cost
medicines ( http://www.pharmac.govt.nz/highcostmeds.asp)
are examples of valuable opportunities to contribute. The Government’s
medicines strategy work ( http://www.moh.govt.nz/moh.nsf/pagesmh/5633/$File/towards-newzealand-medicines-strategy-consult.pdf)
is also an opportunity to look at potential improvements across the whole
medicines system—from research and registration, through to whether
medicines are optimally used, and important parts in-between like
PHARMAC’s role and prescribing decisions.
We believe that PHARMAC’s approach for the funding of
statins has, over time, successfully targeted access to give long-term health
gains. While readers will draw their own
conclusions,1–5 PHARMAC is satisfied that
its work has been careful and, in our view, robust, mindful of responsibilities
to all patient groups across the population—as with all medicines.
Scott Metcalfe Chief Advisor Population Medicine
Peter Moodie Medical Director
PHARMAC Wellington
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Topic/claim
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PHARMAC
response
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Comment
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Population
coverage of statins
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NZ’s
statin usage is comparable internationally and now equals Australia’s, at
1/3rd the cost
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Material on
the British Medical Journal website ( http://bmj.bmjjournals.com/cgi/eletters/328/7436/385#52963)
shows the use of statins has been comparable to other countries.
New
Zealand’s per-capita use of statins is now the same as that of
Australia2—despite the per-capita nominal
costs in New Zealand being 1/3rd that of Australia (Australia spent AUS$886
million on statins in 2005).26
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Patient
access to atorvastatin is less than for simvastatin
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The known
differences in potency between simvastatin and atorvastatin are probably
overstated
Access to
simvastatin is now unrestricted, and atorvastatin remains available as a
second-line agent
A recent
British Medical Journal editorial27 advocates
reference pricing atorvastatin to generic simvastatin in the United Kingdom, as
happens in Germany
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The authors
cite an incomplete published meta-analysis (Law et al BMJ
200328) that did not include head-to-head
trials. Up to April 2004, we had identified 20 additional published head-to-head
randomised parallel group or cross-over studies directly comparing simvastatin
and atorvastatin for LDL-C lowering, with 8,855 patients. Overall it seems that
simvastatin is around 80% as potent at reducing LDL-C as atorvastatin at lower
nominal daily doses (10–40mg) and 90% as potent at 80mg/day.
These
differences are less than those indicated by Law
meta-analysis,28 which was of largely
less-comparable non-head-to-head studies. The Law meta-analysis also did not
include studies published after 2001—e.g.
STELLAR,*29 Karalis et al
200230—and only two of the 164 studies it
used directly compared atorvastatin and simvastatin in the same group of
patients (with 290 patients
studied).31,32
The
Pharmacology and Therapeutics Committee (PTAC) has previously noted that
measures such as LDL-cholesterol reduction (the commonest way to compare between
statins) are ultimately surrogate markers, not clinically relevant outcomes.
There is no head-to-head dose-equivalent outcomes evidence comparing
atorvastatin with simvastatin, and hence no firm basis for stating that either
is better than the other. In terms of surrogate markers, simvastatin appears to
be more effective than atorvastatin for other important surrogate measures such
as raising HDL-C.33,34
PTAC in
February 2006 reviewed the evidence for the current dose equivalence between
atorvastatin and simvastatin, and considered that 1:2 dose equivalence provides
a rough guide, and that in clinical practice the dose of any statin should be
adjusted according to the individual patient’s response [in light of
absolute cardiovascular risk].
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Cholesterol
target levels
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The New
Zealand recommendations seem reasonable
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PTAC in
February 2006 noted the focus on greater reductions in LDL cholesterol. It noted
that LDL targets have been progressively lowered, and also that by increasing
doses to lower LDL levels the risk of side-effects also increased, and that this
can occur with limited additional clinical gains. PTAC recommended that the
target LDL levels remain unchanged, but noted that it may reassess them if the
New Zealand Guidelines Group (NZGG) recommended changes to target LDL
levels.
A recent
paper in the BMJ 35 ( http://bmj.bmjjournals.com/cgi/content/full/332/7555/1419)
suggests that adopting the approach recommended by the NZGG’s
cardiovascular guidelines 36 may be highly
efficient. Modelling the theoretical impacts of various international guidelines
on the Canadian population, the researchers estimated that the New Zealand
guideline was the most efficient of all the guidelines, potentially avoiding
nearly as many deaths as predicted by applying the Australian and British
guidelines while recommending treatment to the fewest number of people (12.9% of
people v 17.3% with the Australian and British
guidelines)—important when treating some patients unnecessarily means not
funding other health priorities.
If their
‘optional’ recommendations are included, the use of the US
guidelines’ recommendations would mean treating about twice as many people
as the New Zealand guidelines (24.5% of the population, an additional 1.4
million people) with almost no increase in the number of deaths avoided.
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PHARMAC
responsiveness to new evidence, as exemplified by issues around statin switching
in 1997.
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Access was
extended to more patients, using a satisfactory if not the best statin. PHARMAC
has already acknowledged that in hindsight the implementation process was
imperfect.37
PHARMAC
subsequently fully funded simvastatin for patients who met defined criteria by
January 1998, and atorvastatin later that year.
There is a
continuum of belief for class effects between evidence from a single clinical
trial and mortality-based studies at doses used in clinical trials in similar
populations.38
There has
been no good evidence of any harm that resulted from the switch from simvastatin
to fluvastatin, and nor of increased mortality as a result of the application of
reference pricing.
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In 1997,
PHARMAC widened access to statins by subsidising fluvastatin and reference
pricing all available statins to it. This meant for the 12,000 existing patients
either a change in medicine or an additional surcharge, but it also offered
access for some 112,500 new patients. PHARMAC had to consider how fluvastatin
compared to simvastatin and the possible risks of reference pricing.
Fluvastatin
did have limited outcome data39,40 although no
significant mortality data. The lipid-lowering effect of fluvastatin was
expected to be 85% that of simvastatin’s at equipotent
doses,41 which needed to be weighed against the
potential to give benefit to many more patients within available
resources.42
There has
been no good evidence of any harm that resulted from the switch from simvastatin
to fluvastatin, and nor of increased mortality as a result of the application of
reference pricing. The Dunedin paper was criticised
internationally44–46 for the following
limitations:
- Comparable
mortality data were not collected—patients treated on simvastatin before
the switch would have had to survive to remain in the cohort, and since no such
restriction occurred after switching to fluvastatin, deaths after the switch
logically should have been excluded.
- Because
it was an uncontrolled before-and-after study, potential bias was introduced by
the unmasking of clinicians who admitted and then assessed patients, and of the
evaluators who extracted and assessed the data.
- The
data before the switch were obtained from the hospital computer system (not
fully reliable), whereas the data after the switch appeared to have been
collected systematically and with care.
- The
analysis tabulated but failed to comment on a key possible reason behind the
reported increase in cholesterol concentrations—being the possible
subtherapeutic dosing of patients with the substituted drug
(fluvastatin).46,47
Both
the New Zealand and Canadian experience has suggested that switching of other
cardiovascular medicines such as DHP CCBs and ACE inhibitors—associated
with reference pricing policies—has not been associated with clear
evidence of worsening population health
outcomes.48–50 We are not aware of any
similar population-based observational analyses for statins. We do acknowledge
here the known biases with such analyses, which need to be interpreted in light
of their methodological limitations versus the costs and availability of more
robust evidence.
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Atorvastatin
2004—PHARMAC response to consultation concerns over proposed switch to
simvastatin for patients using 40mg atorvastatin
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PHARMAC takes
consultation seriously.
The supplier
would have withdrawn for other reasons.
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It is not
clear to PHARMAC that there is any causative link between pharmaceutical sales
in a country and the commercial evaluation of where to locate research
programmes.
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Safety of the
80mg simvastatin dose
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PTAC
considers that statin adverse effects are a class effect
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PTAC’s
February 2006 meeting examined claims by the supplier that the safety of
high-dose atorvastatin was superior to that of high dose simvastatin. PTAC noted
that the risk of adverse effects were dose-related, and considered that risk
factors (dose and potency) were the important issue and that the increase in
adverse effects with increased doses was a class effect and could occur with an
increase in dose of any statin.
PTAC also
considered the use of atorvastatin 80 mg, and noted that in comparison to
moderate doses or 80mg simvastatin, treatment with atorvastatin 80 mg results in
a small additional decrease in LDL cholesterol but may be associated with the
potential for an increase in the risk of adverse effects. Members considered
that if atorvastatin 80 mg was listed in the Pharmaceutical Schedule there would
be a risk that patients would begin atorvastatin at the 80 mg daily dose.
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Need to
protect patients
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This argument
goes both ways
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The authors
cite Begg et al 51 on the need to advocate for
patients. PHARMAC’s response at the time ( http://www.nzma.org.nz/journal/116-1170/361/) 3
was that patients’ needs extend beyond individuals presenting in limited
clinical settings, and the need for a population approach.
Historically,
patients at highest overall cardiovascular risk have tended not to receive
statin treatment, particularly Māori and Pacific men. That is why PHARMAC
is working with DHBs and communities with its One Heart Many Lives programme
attempting to redress this.
It is
PHARMAC’s role to represent the public interest. PHARMAC’s staff are
very mindful of their responsibilities to all patients across all disease and
disability groups—to achieve the best health gains for the New Zealand
population within the funding available.
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References and endnotes:
- Ellis
C, White H. PHARMAC and the statin debacle. N Z Med J. 2006 Jun
23;119(1236):U2033. http://www.nzma.org.nz/journal/119-1236/2033/
- Moodie
P, Dougherty S, Metcalfe S. PHARMAC and statins—getting the best
population health gains. N Z Med J. 2006 Jul 21;119(1238):U2092. http://www.nzma.org.nz/journal/119-1238/2092/
- Moodie
P, Metcalfe S, McNee W. Response from PHARMAC: difficult choices. N Z Med J.
2003 Mar 14;116(1170):U361. http://www.nzma.org.nz/journal/116-1170/361/
- Metcalfe
S, Moodie P. More about cardiovascular disease and lipid management in New
Zealand. N Z Med J. 2002 Oct 11;115(1163):U203. http://www.nzma.org.nz/journal/115-1163/203/
- Metcalfe
S, Dougherty S, Brougham M, Moodie P. PHARMAC measures savings elsewhere to the
health sector. N Z Med J. 2003;116(1170). URL: http://www.nzma.org.nz/journal/116-1170/362/
- Moodie
P, McNee W, Metcalfe S. PHARMAC welcomes debate. N Z Med J. 2005 Jul
15;118(1218):U1572. http://www.nzma.org.nz/journal/118-1218/1572/
- Metcalfe
S, Brougham M, Moodie P, Grocott R. PHARMAC responds to Richard Milne on
discounting health benefits and costs. N Z Med J. 2005 Jul 29;118(1219):U1600.
http://www.nzma.org.nz/journal/118-1219/1601/
- Grocott
R, Metcalfe S. Going against the flow: the impact of PHARMAC not funding COX-2
inhibitors for chronic arthritis. N Z Med J. 2005 Oct 7;118(1223):U1690. http://www.nzma.org.nz/journal/118-1223/1690/
- Metcalfe
S, Moodie P, McNee W. PHARMAC and tobacco control in New Zealand: two licensed
funded options are already available (with responses by Holt et al and the
Editor). N Z Med J. 2005 Jun 24;118(1217):U1544; author reply U1544; discussion
U1544. http://www.nzma.org.nz/journal/118-1217/1544/
- Metcalfe
S, Moodie P. More on PHARMAC and tobacco control in New Zealand N Z Med J. 2006
Jan 27;119(1228):U1837. http://www.nzma.org.nz/journal/119-1228/1837/
- Davies
A, Metcalfe S, Moodie P, McNee W. PHARMAC responds to Stewart Mann on
dihydropyridine calcium channel antagonists. N Z Med J. 2005 Aug
12;118(1220):U1621. http://www.nzma.org.nz/journal/118-1220/1621/
- McNee
W, Moodie P, Schmitt S, Dick A. PHARMAC's response to Tim Blackmore on the sole
supply of influenza vaccine. N Z Med J. 2005 Jul 29;118(1219):U1601. http://www.nzma.org.nz/journal/118-1219/1601/
- Metcalfe
S, Moodie P, Davies A, McNee W, Dougherty S. PHARMAC responds on salbutamol. N Z
Med J. 2005 Aug 26;118(1221):U1644. http://www.nzma.org.nz/journal/118-1221/1644/
- Metcalfe
S, Evans J, Moodie P. PHARMAC responds on long-acting insulin analogues. N Z Med
J. 2005 Oct 28;118(1224):U1716. http://www.nzma.org.nz/journal/118-1224/1716/
- Metcalfe
S, Dougherty S. PHARMAC responds on long-acting inhalers for COPD. N Z Med J.
2005 Nov 11;118(1225):U1743. http://www.nzma.org.nz/journal/118-1225/1743/
- Metcalfe
S, Moodie P, Grocott R, Wilkinson T. PHARMAC responds on TNF inhibitors for
inflammatory arthritis. N Z Med J. 2005 Dec 16;118(1227):U1799. http://www.nzma.org.nz/journal/118-1227/1799/
- Crausaz
S, Metcalfe S. PHARMAC's response on gemcitabine and transparency. N Z Med J.
2005 Nov 11;118(1225):U1741. http://www.nzma.org.nz/journal/118-1225/1741/
- Metcalfe
S, Rasiah D, Dougherty S. PHARMAC responds on treatments for pulmonary arterial
hypertension. N Z Med J. 2005 Dec 16;118(1227):U1805. http://www.nzma.org.nz/journal/118-1227/1805/
- Metcalfe
S, Crausaz S, Moodie P, McNee W. PHARMAC’s response on temozolomide and
funding costly medicines that prolong life shortly. N Z Med J. 2005 Dec
16;118(1227):U1806. http://www.nzma.org.nz/journal/118-1227/1806/
- Moodie
P, Dougherty S. PHARMAC's response on clopidogrel. N Z Med J. 2006 Feb
17;119(1229):U1872. http://www.nzma.org.nz/journal/119-1229/1872/
- Moodie
P. PHARMAC responds on tolterodine for overactive bladder. N Z Med J. 2005 Feb
17;119(1229):U1871. http://www.nzma.org.nz/journal/119-1229/1871/
- Metcalfe
S, Wilkinson T, Rasiah D. PHARMAC responds on agents to prevent osteoporotic
fractures. N Z Med J. 2006 Mar 10;119(1230):U1895. http://www.nzma.org.nz/journal/119-1230/1895/
- Moodie
P, Metcalfe S, Dougherty S. PHARMAC and EpiPen for anaphylaxis. N Z Med J. 2006
Jun 23;119(1236):U2038. http://www.nzma.org.nz/journal/119-1236/2038/
- Grocott
R, Metcalfe S, Moodie P. PHARMAC and erythropoietin for cancer patients. N Z Med
J. 2006 Jun 23;119(1236):U2039. http://www.nzma.org.nz/journal/119-1236/2039/
- Grocott
R, Moodie P. PHARMAC seeks clinical feedback on its cost-utility analysis
methodology. N Z Med J. 2006 Aug 4;119(1239):U2113. http://www.nzma.org.nz/journal/119-1239/2113/
- source:
PHARMAC analysis of (1) NZHIS PharmWarehouse dispensings and scripts data for
statins, and (2) PBS services data at http://www.medicareaustralia.gov.au/statistics/dyn_pbs/forms/pbs_tab1.shtml,
using PBS codes (http://www9.health.gov.au/pbs/scripts/search.cfm)
for atorvastatin, fluvastatin, pravastatin and simvastatin (codes 8213G, 8214H,
8215J, 8521L, 8023G, 8024H, 2833D, 2834E, 8197K, 2011W, 2012X, 8173E, 2013Y,
8313M, 2831B). Population denominators obtained from http://www.stats.govt.nz/ and http://www.abs.gov.au/
- Moon
JC, Bogle RG. Switching statins. BMJ. 2006;332:1344-5. http://bmj.bmjjournals.com/cgi/content/full/332/7554/1344
- Law
MR, Wald NJ, Rudnicka AR. Quantifying effect of statins on low density
lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review
and meta-analysis. BMJ. 2003 Jun 28;326(7404):1423. http://bmj.bmjjournals.com/cgi/content/full/326/7404/1423
- Jones
PH, Davidson MH, Stein EA, Bays HE, McKenney JM, Miller E, Cain VA, Blasetto JW;
STELLAR Study Group. Comparison of the efficacy and safety of rosuvastatin
versus atorvastatin, simvastatin, and pravastatin across doses (STELLAR* Trial).
Am J Cardiol. 2003 Jul 15;92(2):152-60.
- Karalis
DG, Ross AM, Vacari RM, Zarren H, Scott R. Comparison of efficacy and safety of
atorvastatin and simvastatin in patients with dyslipidemia with and without
coronary heart disease. Am J Cardiol. 2002 Mar 15;89(6):667-71.
- PHARMAC
analysis (2004) using the component data referred to in the BMJ meta-analysis,
found at http://www.smd.qmul.ac.uk/wolfson/bpchol/B5.pdf
- The
rest of the data used by the Law meta-analysis are less robust, in that they are
indirect comparisons. All of the sixty other relevant studies just compared
atorvastatin against placebo, or simvastatin against placebo, and in various
doses. The meta-analysis then combined these disparate data sources, arising
from different studies using different designs from different patient
populations. Although this is a valuable way to combine the results of many
different studies to obtain an overview, we believe that it cannot substitute if
there are head-to-head trials available—which randomise patients to
parallel groups of atorvastatin or simvastatin at various doses and then measure
effects in a standardised way using the same source population.
- Wierzbicki
AS, Mikhailidis DP. Dose-response effects of atorvastatin and simvastatin on
high-density lipoprotein cholesterol in hypercholesterolaemic patients: a review
of five comparative studies. Int J Cardiol. 2002 Jul;84(1):53-7.
- Illingworth
DR, Crouse JR 3rd, Hunninghake DB, Davidson MH, Escobar ID, Stalenhoef AF,
Paragh G, Ma PT, Liu M, Melino MR, O'Grady L, Mercuri M, Mitchel YB; Simvastatin
Atorvastatin HDL Study Group. A comparison of simvastatin and atorvastatin up to
maximal recommended doses in a large multicenter randomized clinical trial. Curr
Med Res Opin. 2001;17(1):43-50.
- Manuel
DG, Kwong K, Tanuseputro P, Lim J, Mustard CA, et al. Effectiveness and
efficiency of different guidelines on statin treatment for preventing deaths
from coronary heart disease: modelling study. BMJ. 2006 Jun 17;332(7555):1419.
Epub 2006 May 31. http://bmj.bmjjournals.com/cgi/content/full/332/7555/1419
- New
Zealand Guidelines Group. The assessment and management of cardiovascular risk.
Wellington: New Zealand Guidelines Group, 2003. (www.nzgg.org.nz/guidelines/0035/CVD_Risk_Full.pdf#page=33)
- McNee
W, Smart T. Statins and PHARMAC. N Z Med J. 1999;112:55-6.
- Wierzbicki
AS, Reynolds TM, Crook MA, Jackson G. Are drugs interchangeable? Lancet.
2000;355:317.
- Riegger
G, Abletshauser C, Ludwig M, et al. The effect of fluvastatin on cardiac events
in patients with symptomatic coronary artery disease during one year of
treatment. Atherosclerosis. 1999;144:263-70.
- Herd
JA, Ballantyne CM, Farmer JA, et al. Effects of fluvastatin on coronary
atherosclerosis in patients with mild to moderate cholesterol elevations
(Lipoprotein and Coronary Atherosclerosis Study [LCAS]). Am J Cardiol
1997;80:278-86.
- Canadian
Coordinating Office for Health Technology Assessment. HMG-CoA Reductase
Inhibitors: A Review of Published Clinical Trials and Pharmacoeconomic
Evaluations. 1997. CCOHTA Report 1997: 5E. http://ccohta.ca/publications/pdf/statins_e.pdf
- Bennett
W. Statins. N Z Med J 1998;11:194-5.
- Thomas
M, Mann J. Increased thrombotic vascular events after change of statin. Lancet.
1998;352:1830-1.
- Weiss
NS, Heckbert SR. Thrombotic vascular events after change of statin. Lancet
1999;353:844
- Ikeda
U, Shimpo M, Shimada K. Thrombotic vascular events after change of statin.
Lancet 1999;353:844-5
- Wierzbicki
AS, Crook MA, Reynolds TM, Jackson G. Thrombotic vascular events after change of
statin. Lancet 1999;353:845.
- McNee
W, Moodie P, Metcalfe S. Are drugs interchangeable? Lancet. 2000;355:316-7.
- Perkins
E, Dovey S, Tilyard M, Boyle K, Penrose A. A change management strategy to
modify ACE inhibitor prescribing. Dunedin RNZCGP Unit, 1999.
- Schneeweiss
S, Walker AM, Glynn RJ, et al. Outcomes of reference pricing for
angiotensin-converting-enzyme inhibitors. N Engl J Med. 2002;346:822-9.
- Schneeweiss
S, Soumerai SB, Maclure M, Dormuth C, Walker AM, Glynn RJ. Clinical and economic
consequences of reference pricing for dihydropyridine calcium channel blockers.
Clin Pharmacol Ther. 2003 Oct;74(4):388-400.
- Begg
E, Sidwell A, Gardiner S, Nicholls G, Scott R. The sorry saga of the statins in
New Zealand—pharmacopolitics versus patient care. N Z Med J
2003;116(1170). http://www.nzma.org.nz/journal/116-1170/360
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