E-drug: ADRs and cox 2 inhibitors (cont)
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CELECOXIB: EARLY AUSTRALIAN REPORTING EXPERIENCE
Australian Adverse Drug Reaction Bulletin, Vol 19, No 2, June 2000.
Celecoxib (Celebrex) is the first in the class of COX-2 inhibitors to
be marketed in Australia. From the start of marketing in October 1999
to April 2000, ADRAC received 919 reports of suspected adverse
reactions.
869 reports show celecoxib was the only suspected drug. Relatively
minor gastrointestinal adverse reactions (nausea, abdominal pain,
dyspepsia, diarrhoea) have been mentioned commonly. There have been
relatively few reports of serious upper or lower gastrointestinal
adverse reactions (31 and 28 reports respectively). This is
consistent with clinical trial comparisons of celecoxib with the more
conventional NSAIDs naproxen and diclofenac.1 Some patients do
develop GI ulcers or bleeds while taking celecoxib. It is uncertain
at this stage whether this reflects a background rate for these
problems or whether the drug is being used in preference to other
NSAIDs in a high-risk group of patients.
There have been nine reports which describe either acute renal
failure or worsening of chronic renal failure. Consistent themes in
these reports were that the patients were elderly (59; 70 to 94
years) and that in six of the reports, the patients were taking both
an ACE inhibitor and a diuretic at the time the celecoxib was
started. It appears that celecoxib shares the propensity of the
conventional NSAIDs to worsen renal function in patients taking the
combination of these 3 drug classes (the "triple whammy"). 2
Several other types of reactions appear to be prominent with celecoxib:
There is a high proportion of rashes/urticaria but few reports of
serious reactions such as Stevens Johnson syndrome (1 report) or
erythema multiforme. (2) About 5% of the reports have mentioned
other forms of allergy including face or tongue oedema, and
angioedema (7) and anaphylactoid reaction (3). There are also reports
of asthma or aggravation of asthma.
Peripheral oedema has been described often; eleven reports described
varying degrees of hypertension. Dizziness and headache have been
reported commonly. Celecoxib sometimes increases the INR in patients
taking warfarin and this has been reported to ADRAC 7 times.
In its first months of marketing, celecoxib has generated a large
number of reports to ADRAC. Apart from the gastrointestinal tract,
its adverse effect profile appears similar to that of a conventional
NSAID.
References:
1. Celecoxib, approved product information
2. ADRAC, Thomas MC. Diuretics, ACE inhibitors and NSAIDs - the
triple whammy. MJA 2000; 172: 184-5.
Ian Boyd
Adverse Drug Reactions Unit
Canberra
Australia
Ian Boyd <Ian.Boyd@health.gov.au>
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