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SJ Doc wrote:
> On 8 Sep 2005 12:42:05 -0700, "fresh~horses" wrote:
>
> >'New' drugs too often offer little new
> >Breakthrough drugs are rare. Most newcomers driving up
> >costs are just me-too marketing darlings
~~~~~~~~~~~~~~~~~~~
http://healthyskepticism.org/adwatch/au/2003/nexium.php
The Nexium advertisement appeals to our desire for power.
Appeals to desires are common in advertising because they work.[1]
These appeals work despite the evidence that we normally do not give
them much thoughtful attention. Lack of attention can allow these
appeals to sneak into the brain under the radar of critical
appraisal.[2]
Unfair comparisons
The Nexium advertisement claims that "Nexium 40mg offers greater
healing power that either omeprazole or lansoprazole". This claim is
based on two unfair comparisons.
One of the comparisons is esomeprazole (Nexium) 40mg vs omeprazole
(Losec, Acimax, Probitor) 20mg. (The dose of omeprazole is only
disclosed in the fine print.)
Omeprazole is a proton pump inhibitor that has been used for years to
treat peptic ulcers and gastro-oesophageal reflux disease by reducing
gastric acid levels.
Omeprazole 20mg contains about 10mg of S-omeprazole and 10mg of its
mirror molecule: R-omeprazole. Both S and R-omeprazole are converted to
the same active drug that reduces production of gastric acid by proton
pumps. R-omeprazole is absorbed into the body less than S-omeprazole
and removed faster, so it may be less effective than S-omeprazole.
Esomeprazole is just a different spelling for S-omeprazole. "Es" =
"S-". AstraZeneca are using a different spelling that makes it
less obvious that esomeprazole is just half of their old drug
omeprazole (Losec).
It is no surprise that 40mg S-omeprazole in Nexium 40mg is more
effective than the 10mg of S-omeprazole plus 10mg of R-omeprazole.
However a larger dose of omeprazole would be just as "powerful" as
esomeprazole (Nexium) 40mg.
The other comparison is esomeprazole (Nexium) 40mg vs lansoprazole
(Zoton) 30mg. (Again the dose of lansoprazole is only disclosed in the
fine print.)
The graph below suggests that the difference in the percentage healed
at 8 week is too small to be clinically significant.[3] Patients are
unlikely to be able to detect a worthwhile difference in relief of
symptoms.
Chart
Missing comparisons
The advertisement does not compare Nexium with other alternatives. The
alternatives that should be considered include other proton pump
inhibitors, other drugs and non-drug therapies.
The only trial comparing esomeprazole with pantoprazole that we are
aware of was published in September 2003 so it is too recent to be
mentioned in the advertisement.[4] That trial suggests that
esomeprazole 40mg is unlikely to have any clinically significant
advantages over pantoprazole 40mg. This is despite evidence that
pantoprazole 40mg is not significantly better than omeprazole 20mg.[5]
Both can be true because there is little difference between proton pump
inhibitors especially at higher doses. This is because of the law of
diminishing returns as shown in the graph below.
Chart
Many people with gastro-oesophageal reflux disease can be
adequately treated long term with lifestyle changes including elevation
of the head of the bed plus antacids or H2 antagonists such as
ranitidine (Multiple brands).[6]
Many people with peptic ulcers are better treated with H. pylori
bacteria eradication therapy.
General Recommendation
There is no proven clinically significant efficacy or safety advantage
of Nexium over fair comparison doses of other proton pump inhibitors.
When a proton pump inhibitor is appropriate, use whichever is the
cheapest at the time in the lowest dose that controls the symptoms.
Current Recommendation for Australia
The table below includes all proton pump inhibitors listed in the
Pharmaceutical Benefits Scheme Yellow Book effective from 1 August 2003
in order of the cost of a pack of 30 tablets or capsules.
rabeprazole 10 mg
Pariet
$ 27.60
omeprazole 10 mg
Losec
$ 29.55
pantoprazole 20 mg
Somac
$ 30.43
lansoprazole 15 mg
Zoton
$ 30.98
esomeprazole 20 mg
Nexium
$ 46.19
omeprazole 20 mg
Acimax, Probitor
$ 46.19
rabeprazole 20 mg
Pariet
$ 46.19
omeprazole 20 mg
Losec
$ 47.69
pantoprazole 40 mg
Somac
$ 48.50
lansoprazole 30 mg
Zoton
$ 49.36
esomeprazole 40mg
Nexium
$ 75.26
As doses increase prices increase but differences in efficacy diminish.
The best value approach may be:
· Commence therapy with lifestyle changes plus esomeprazole
20mg (Nexium). This will quickly control symptoms for most patients.[7]
· If symptoms are not controlled try pantoprazole 40mg (Somac)
before using esomeprazole 40mg (Nexium) as a last resort.
· If symptoms are controlled then try lifestyle measures alone
or add a H2 antagonist such as ranitidine (Multiple brands) or
rabeprazole 10mg (Pariet) for maintenance.
Further reading
Do Single Stereoisomer Drugs Provide Value?
Therapeutics Letter, issue 45, June - September 2002
http://www.ti.ubc.ca/pages/letter45.htm
Jankowski J, Jones R, Delaney B, Dent J.
10-minute consultation: Gastro-oesophageal reflux disease.
BMJ. 2002 Oct 26;325(7370):945.
http://bmj.bmjjournals.com/cgi/content/full/325/7370/945
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