CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 6, November/December 2010
AFRICA
341
benefits, are we doing more harm than
good in the long run? Having said that,
the inferences made from the Sipahi
et al
.
1
study that the risk of cancer is increased
in patients taking ARBs is concerning to
say the least.
The most important tenant of clinical
trials is to determine which statistical
endpoints need to be defined prior to
commencing any study, and any
post-
hoc
analysis needs to be treated with
the contempt that it deserves. To group
a number of studies involving the ARBs
(meta-analysis) and to extrapolate that
there is an increased incidence of cancer
in certain groups of patients is bad medi-
cine and the outcomes of this report
should not influence the use of these
agents in patients.
The analysis is contradictory – there
is an increase in lung cancer, which is
claimed to be statistically significant in
the group of patients receiving ARBs,
yet the incidence of other cancers is
decreased or the same. The group of
patients that would typically be enrolled
in these studies is firstly, a group of
patients that are high risk for lung cancer,
as they no doubt include a skewed bias
in favour of smokers. All these factors
would need to be included in the statisti-
cal design of the study prior to drawing
these conclusions.
At this stage, I can find no reason to
be concerned about the use of ARBs in
patients. Far more reliable prospective,
randomised data need to be presented
prior to considering withdrawing this
class of drug from the market.
It is rather ironic that there is a concern
regarding a slight increase in cancer inci-
dence in patients using ARBs in a retro-
spective analysis of numerous studies, yet
a medication that is used widely and is
known to have far greater impact on the
development of breast cancer in women
is prescribed in far greater numbers on a
daily basis by doctors around the world –
oestrogen replacement therapy – without
as much as a mention in widely read
medical journals!
C Lombard, Biostatistics Unit, Medical Research
Council; Dr Adam Nosworthy, oncologist, Donald
Gordon Oncology Centre; J Aalbers, Special
Assignments Editor
4. Sipahi I, Debanne SM, Rowland DY, Simon
DI, Fang J. Angiotensin-receptor block-
ade and risk of cancer: meta-analysis of
randomised controlled trials. Published
online June 14, 2010 DOI:10.1016/51470-
2045(10)70106-6.
5. Nissen SE. Comment: Angiotensin-receptor
blockers and cancer: urgent regulatory
review needed. Published online. June 14
2010;DOI:10.1016/51470-2045(10)70142X.
FDA committee unanimously recommends approval of dabigatran
etexilate for stroke prevention in atrial fibrillation
The US Food and Drug Administration
(FDA) Cardiovascular and Renal Drugs
Advisory Committee recently voted 9 to
0 in favour of recommending dabigatran
etexilate for stroke prevention in patients
with atrial fibrillation (AF).
For decades, vitamin K antagonists
such as warfarin have been the most
efficacious therapeutic option for stroke
prevention in AF. Current recommen-
dations for patients with non-valvular
atrial fibrillation treated with warfarin
recommend maintaining an international
normalised ratio (INR) in the range of
2.0–3.0 through frequent blood monitor-
ing and dose adjustments, which can be
challenging for physicians and patients.
In RE-LY
®
, dabigatran etexilate
demonstrated efficacy without the need
for ongoing INR monitoring or dose
adjustments. Furthermore, there were no
food restrictions on those taking dabi-
gatran in RE-LY
®
. A total of 6.3 million
people in the USA, Japan, Germany,
Italy, France, UK and Spain were living
with AF in 2007 and this is expected to
increase to 7.5 million by 2017, primarily
due to the ageing population.
1
‘We are pleased with the committee’s
recommendation, which marks an impor-
tant step in advancing care for patients
with atrial fibrillation’, said Prof Klaus
Dugi, Corporate Senior Vice President
Medicine, Boehringer Ingelheim. ‘We
believe dabigatran etexilate will offer
patients and doctors the first new treat-
ment option for stroke prevention in atrial
fibrillation in more than 50 years. We
look forward to working with the FDA as
it finalises its review of dabigatran.’
Pradaxa (75 and 110 mg) is currently
only registered in South Africa for the
prevention of venous thromboembolic
events in patients who have undergone
hip- and knee-replacement surgery. For
full prescribing information refer to the
package insert approved by the Medicines
Regulatory Authority.
For more information visit
ingelheim.com, or contact Sue Thomas, Medical
InformationManagerontel:+270(11)348-2514or
e-mail:
J Aalbers, A Bryer, E Klug
1. Benyoucef S, Hughes M, Mehta N. Atrial
fibrillation. Decision Resources, December
2008.
Drug Trends in Cardiology
