Celebrex
and Vioxx were approved for the U.S. market back in 1999 for
the treatment of arthritis and other types of pain. Both of
the drugs constituted a new class of drugs called Cox-2 inhibitors.
Their release seemed to be cause for celebration for individuals
who had previously taken aspirin or other NSAIDs (nonsteroidal
anti-inflammatory drugs), but were bothered by gastrointestinal
problems commonly associated with them.
Celebrex
and Vioxx were touted as great medical developments in the many
ads that promoted their benefits. Principal among these was
the claim that Vioxx and Celebrex relieved pain without causing
stomach problems. Specifically, these Cox-2 inhibitors are prescribed
to relieve symptoms commonly associated with osteoarthritis,
menstrual cramps, or other acute pain. Unfortunately, Vioxx
and Celebrex pose troubling effects for some users.
The
Heightened Risk of Heart Attack Linked to Vioxx
Recent
studies have shown that Vioxx can increase the incidence of
heart attack nearly four times greater than that of traditional
arthritis pain relievers like NSAIDS. More specifically, the
new study out of the Cleveland Clinic noted an increase in the
development of myocardial infarctions, or heart attacks, in
people treated with Vioxx, when compared with those treated
with naproxen (a standard NSAID). While the risk of heart attack
is still low, it is a concern for those users who may have had
cardiac problems in the past.
Whether the increased risk of heart attack is attributable to
a property of Cox-2 inhibitors (this includes both Vioxx and
Celebrex), or whether it is solely specific to Vioxx, is not
yet known.
Deaths
Linked to Celebrex
While
the recent report linked heart attacks specifically to Vioxx,
this does not mean that Celebrex is not without its risks as
well. Several years ago when the drug initially came to market,
The Wall Street Journal ran a story that spread throughout the
media linking Celebrex to 10 deaths during its first three months.
In addition, there were eleven other cases of gastrointestinal
hemorrhage associated with the drug. The Wall Street Journal
obtained the information from the FDA's Freedom of Information
Act. Of the ten deaths, half of them were from ulcers (also
known as gastrointestinal bleeding). Two of the deaths occurred
from heart attack, one to a kidney problem, one to an interaction
with another drug, and no cause was given for the other death.
While nothing came of this story (i.e. Celebrex was not deemed
responsible for the deaths), the recent revelations bring to
life once again the potential dangers associated with Cox-2
inhibitors.
The association between Cox-2 inhibitors and health concerns
has prompted the Food and Drug Administration (FDA) to consider
adding warning labels to Vioxx and Celebrex about the potential
risk of cardiovascular problems.
Complications with the name Celebrex
Celebrex
has also made news for the complications and mistakes made due
to the similarities between its name and other drugs. Over 50
reports of errors have been recorded that Celebrex was mistaken
for either Cerebyx and Celexa. Cerebyx is an intravenous drug
used to treat epilepsy, while Celexa is a medication used to
treat depression.
Thankfully, the confusion between the names has not led to any
serious problems or deaths. Ten of the cases involved a patient
actually receiving the wrong drug, 24 of them were simply reports
by patient or doctor about the name confusion, and the remaining
19 involved prescriptions being made but the mistakes were caught
before the patient received the medication.
Although this does not appear a cause of concern, the largest
number of errors may be much greater given the fact that 95%
of medication errors are never reported.
Cox-2
Inhibitors
Cox-2
inhibitors inhibit the enzyme involved in inflammation of body
tissue. Traditional NSAIDs inhibit both the Cox-1 and Cox-2
enzymes. The problem with this is that they stop the "good"
Cox-1 enzyme that helps protect the lining of the stomach. Cox-2
inhibitors, in theory at least, do not impair the good Cox-1
enzyme, only the Cox-2 enzyme that is responsible for inflammation.
Cox-2 inhibitors therefore cause less gastrointestinal problem
However,
Cox-2 inhibitors are not without their problems. They increase
the risk of heart attack. The reason for this may be a simple
difference between what enzymes are inhibited in the platelets
by these drugs. One theory for this holds that the Cox-1 enzyme
plays a role in preventing clot formation that leads to heart
problems.
So
aspirin and other nonsteroidal drugs that inhibit the Cox-1
enzyme probably protect people from developing heart attacks,
whereas, Cox-2 inhibitors don't protect people from developing
heart attacks.
The
Effectiveness of Vioxx and Celebrex
Many
experts in the field are not convinced that Celebrex or Vioxx
are more effective for pain relief than traditional nonsteroidal
drugs (NSAIDS). There does seem to be substantial evidence that
both drugs are safer in regards to gastrointestinal side effects,
like ulcer, gastrointestinal bleeding or obstructions. However,
the manufacturers of the drugs were unable to convince the FDA
to allow them to market the drugs as being safer on the stomach
than other NSAIDS. The only thing the companies managed to do
was to raise concerns about the risk they posed to consumers
with regards to cardiovascular problems.
Clinical trials that led to the approval of Celebrex and Vioxx
suggested that the drugs were safer on the stomach. But the
manufacturers had to conduct longer-term studies to drop a warning
about serious ulcers that all NSAIDs carry. The conclusion of
FDA medical officer Maria Lourdes Villalba was that Vioxx should
continue to carry the same warning as other NSAIDs regarding
gastrointestinal (GI) problems like ulcers, bleeding and perforation.
Villalba also noted that the risk of heart attack and stroke
should be added to the label.
The
Business of it all
Vioxx
is made by Merck, while Celebrex is jointly marketed by Pharmacia
and Pfizer. These Cox-2 inhibitors generate billions of dollars
in sales for these big pharmaceutical companies. News of the
potential risks posed will undoubtedly hurt the future sales
of the drugs.
What
to do if you are currently taking Vioxx or Celebrex?
The
most important step for patients currently taking Vioxx or Celebrex
is to discuss their health and history with their physician.
Your doctor is hopefully aware of the potential health risks
associated with these Cox-2 inhibitors and may advise using
low-dose aspirin or some other alternative in order to minimize
the risk of heart disease from these drugs. Patients must educate
themselves on the potential risks, and, if they experience any
side effects associated with Cox-2 inhibitors, need to immediately
contact their doctor.
