The Food and Drug Administration (FDA) today announced its
new decision to restrict use of antibiotic Ketek (Telithromycin) based on
reports of severe adverse effects associated with this drug.
The antibiotic Ketek was originally approved in 2004 and is
manufactured by Sanofi Aventis. From now on, the drug is no long indicated for
use in patients with acute bacterial sinusitis and acute bacterial
exacerbations of chronic bronchitis.
However, Ketek will remain on the market for the treatment
of community acquired pneumonia of mild to moderate severity, which is acquired
outside of hospitals or long-term care facilities.
In addition, the FDA requires that the drug maker put on the
label a "boxed warning", FDA's strongest form of warning to indicate
that Ketek is contraindicated (should not be used) in patients with myasthenia
gravis, a disease that causes muscle weakness.
The federal agency also worked with the manufacturer to
develop a Patient Medication Guide, which is to be distributed along with each
prescription, to inform patients of the risk of the drug and advise them how to
use it safely.
"Today's action is the result of comprehensive
scientific analysis and thoughtful public discussion of the data available for
Ketek, and includes important changes in the labeling designed to improve the
safe use of Ketek by patients and give healthcare providers the most up-to-date
prescribing information," said Steven Galson, M.D., Director, Center for
Drug Evaluation and Research.
Specific drug-related adverse events including visual
disturbances and loss of consciousness are to be strengthened on the label.
Warnings for hepatic toxicity (rare but severe symptoms of liver disease) were
already strengthened in June 2006, according to the FDA.
A joint advisory committee comprised of FDA's Anti-Infective
Drugs and Drug Safety and Risk Management Advisory committees advised that the
benefits of the drug outweigh its risk for patients with community acquired
pneumonia.
But they said for patients with acute bacterial sinusitis or
acute bacterial exacerbation of chronic bronchitis, the risk is too great to
allow the antibiotic for these conditions.
The committee also recommended a boxed warning as well as
Medication Guide for the drug.
On January 20, 2006, the FDA advised the public that the
Annals of Internal Medicine had published an article reporting three patients
who experienced serious liver toxicity following administration of Ketek
(telithromycin).
These cases had also been reported to FDA MedWatch.
Telithromycin is marketed and used extensively in many other countries,
including countries in Europe and
Japan.
This is a summary of the most important information about
Ketek. For details, talk to your healthcare professional.
What is Ketek used for?
Ketek is an antibiotic used to treat adults 18 years of age
and older with certain respiratory (lung and sinus) infections caused by
certain germs called bacteria. Ketek kills many of the types of bacteria that
can infect the lungs and sinuses, and has been found to treat these infections
safely and effectively in clinical trials. Not all respiratory infections are
caused by bacteria. For example, common colds are caused by viruses. Ketek,
like other antibiotics, does not kill viruses.
Who should not take Ketek?
You must not take Ketek if you:
* have ever had a
severe allergic reaction to Ketek or to any of the group of antibiotics known
as “macrolides” such as erythromycin, azithromycin (Zithromax), clarithromycin
(Biaxin) or dirithromycin (Dynabac).
* are currently
taking cisapride (Propulsid) or pimozide (Orap).
* have ever
experienced side effects on the liver while taking Ketek or other antibiotics
called macrolides (erythromycin, clarithromycin or azithromycin).
Special Warnings with Ketek:
There have been reports of side effects on the liver,
including severe liver disease. In some cases, liver damage worsened rapidly
and happened after just a few doses of Ketek. If you develop signs or symptoms
of hepatitis (liver disease), such as tiredness, body aches, loss of appetite,
nausea, jaundice (yellow color of the skin and/or eyes), dark urine,
light-colored stools, itchy skin, or belly pains, stop your medication and
immediately contact your healthcare provider.
If you have myasthenia gravis, you should talk to your
healthcare provider about other treatments before taking Ketek. There have been
reports of worsening of myasthenia gravis symptoms in patients with myasthenia
gravis taking Ketek. If you have myasthenia gravis and experience worsening of
your symptoms (such as muscle weakness, difficulty breathing) during treatment
with Ketek, you should stop taking Ketek and seek immediate medical attention.
General Precautions with Ketek:
* Ketek may cause
problems with vision, particularly when looking quickly between objects close
by and objects far away. These events include blurred vision, difficulty
focusing, and objects looking doubled. Some patients have severe problems with
vision that may interfere with normal activities.
Most events were mild to moderate; however,
severe cases have been reported.
These
problems lasted several hours and in some patients come back with the next
dose. People taking Ketek should be careful when driving a motor vehicle,
operating heavy machinery, or engaging in otherwise hazardous activities.
* There have been
reports of side effects on the liver. Signs of jaundice include yellow color of
the skin and/or eyes.
What should I tell my healthcare provider?
Tell your healthcare provider if you:
* have, or if a
relative has, a rare heart condition known as congenital prolongation of the QT
interval.
* are being
treated for heart rhythm disturbances with certain medicines known as
antiarrhythmics (such as quinidine, procainamide, or dofetilide), or if you
have low blood potassium (hypokalemia), or low blood magnesium (hypomagnesemia)
* have a disease
known as myasthenia gravis.
* are pregnant,
planning to become pregnant, or are nursing.
* have ever
experienced jaundice (yellow color of the skin and/or eyes) while taking Ketek.
* have any other
serious medical conditions, including heart, liver, or kidney disease.
Tell your healthcare provider about all the medicines you
take, including prescription and non-prescription medicines, vitamins, and
herbal supplements.
Especially tell your
healthcare provider if you take:
* cisapride
(Propulsid) or pimozide (Orap).
* simvastatin,
lovastatin, or atorvastatin (used for lowering cholesterol). You should stop
treatment with these medications while you are taking Ketek.
* medicines that
correct heart rhythm called “antiarrhythmics” (such as quinidine, procainamide,
or dofetilide).
* any of the
following medicines: itraconazole, ketoconazole, midazolam, digoxin, ergot
alkaloid derivatives, cyclosporine, carbamazepine, hexobarbital, phenytoin,
tacrolimus, sirolimus, metoprolol, theophylline, rifampin, or warfarin and
other oral anticoagulants (sometimes called blood thinners).
* medicines called
diuretics (also sometimes called water pills) such as furosemide or
hydrochlorothiazide.
What are some possible side effects of Ketek? (This list is
NOT a complete list of side effects reported with Ketek.
Your healthcare provider can discuss with you
a more complete list of side effects.)
The most common side effects of Ketek include:
* nausea
* headache
* dizziness
* vomiting
* diarrhea. If
diarrhea persists call your healthcare provider.
For more detailed information about Ketek, ask your
healthcare provider or pharmacist.
This is
historical information only.
The information in this sheet has been updated and is addressed in
product labeling including a MedGuide for patients. http://www.fda.gov/cder/foi/label/2007/021144s012medg.pdf
Acknowledgement: the article contains content from a news release by FDA and the questions and answers are completely cited from the FDA website.