Antibiotics are important drugs, often restoring health and
even saving lives. But like all drugs, they can have unwanted and serious side
effects, some of which may not become apparent until many thousands of patients
have been treated.
Such is the case with an important class of antibiotics
known as fluoroquinolones. The best known are Cipro (ciprofloxacin), Levaquin
(levofloxacin) and Avelox (moxifloxacin). In 2010, Levaquin was the
best-selling antibiotic in the United States.
But by last year it was also the subject of more than 2,000
lawsuits from patients who had suffered severe reactions after taking it.
Part of the problem is that fluoroquinolones are often
inappropriately prescribed. Instead of being reserved for use against serious,
perhaps life-threatening bacterial infections like hospital-acquired pneumonia,
these antibiotics are frequently prescribed for sinusitis, bronchitis, earaches
and other ailments that may resolve on their own or can be treated with less
potent drugs or nondrug remedies — or are caused by viruses, which are not
susceptible to antibiotics.
In an interview, Mahyar Etminan, a pharmacological
epidemiologist at the University of British Columbia, said the drugs were
overused “by lazy doctors who are trying to kill a fly with an automatic
weapon.”
Dr. Etminan directed a study published in April in The
Journal of the American Medical Association showing that the risk of suffering
a potentially blinding retinal detachment was nearly fivefold higher among
current users of fluoroquinolones, compared with nonusers. In another study
submitted for publication, he documented a significantly increased risk of
acute kidney failure among users of these drugs.
The conditions Dr. Etminan has studied are relatively easy
to research because they result in hospitalizations with diagnoses that are
computerized and tracked in databases. Far more challenging to study are the
array of diffuse, confusing symptoms suffered by fluoroquinolone users like Lloyd
Balch, a 33-year-old Manhattan resident and Web site manager for City College
of New York.
In an interview, Mr. Balch said he was healthy until April
20, when a fever and cough prompted him to see a doctor. Nothing was heard
through a stethoscope, but a chest X-ray indicated a mild case of pneumonia,
and he was given Levaquin. Although he had heard of problems with Levaquin and
asked the doctor if he might take a different antibiotic, he was told Levaquin
was the drug he needed.
After just one dose, he developed widespread pain and
weakness. He called to report this reaction, but was told to take the next
dose. But the next pill, he said, “eviscerated” him, causing pain in all his
joints and vision problems.
Debilitating Side Effects
In addition to being unable to walk uphill, climb stairs or
see clearly, his symptoms included dry eyes, mouth and skin; ringing in his
ears; delayed urination; uncontrollable shaking; burning pain in his eyes and
feet; occasional tingling in his hands and feet; heart palpitations; and muscle
spasms in his back and around his eyes. Though Mr. Balch’s reaction is unusual,
doctors who have studied the side effects of fluoroquinolones say others have
suffered similar symptoms.
Three and a half months after he took that second pill,
these symptoms persist, and none of the many doctors of different specialties
he has consulted has been able to help. Mr. Balch is now working with a
physical therapist, but in a phone consultation with Dr. David Flockhart, an
expert in fluoroquinolone side effects at the Indiana University School of
Medicine, he was told it could take a year for his symptoms to resolve, if they
ever do disappear completely.
Guidelines by the American Thoracic Society state that
fluoroquinolones should not be used as a first-line treatment for
community-acquired pneumonia; it recommends that doxycycline or a macrolide be
tried first. Mr. Balch didn’t know this, or he might have fought harder to get
a different antibiotic.
Adverse reactions to fluoroquinolones may occur almost
anywhere in the body. In addition to occasional unwanted effects on the
musculoskeletal, visual and renal systems, the drugs in rare cases can
seriously injure the central nervous system (causing “brain fog,” depression,
hallucinations and psychotic reactions), the heart, liver, skin (painful,
disfiguring rashes and phototoxicity), the gastrointestinal system (nausea and
diarrhea), hearing and blood sugar metabolism.
The rising use of these potent drugs has also been blamed
for increases in two very serious, hard-to-treat infections:
antibiotic-resistant Staphylococcus aureus (known as MRSA) and severe diarrhea
caused by Clostridium difficile. One study found that fluoroquinolones were
responsible for 55 percent of C. difficile infections at one hospital in
Quebec.
Fluoroquinolones carry a “black box” warning mandated by the
Food and Drug Administration that tells doctors of the link to tendinitis and
tendon rupture and, more recently, about the drugs’ ability to block neuromuscular
activity. But consumers don’t see these highlighted alerts, and patients are
rarely informed of the risks by prescribing doctors. Mr. Balch said he was
never told about the black-box warnings.
Lack of Long-Term Studies
No one knows how often serious adverse reactions occur. The
F.D.A.’s reporting system for adverse effects is believed to capture only about
10 percent of them. Complicating the problem is that, unlike retinal
detachments that were linked only to current or very recent use of a fluoroquinolone,
the drugs’ adverse effects on other systems can show up weeks or months after
the treatment ends; in such cases, patients’ symptoms may never be associated
with prior fluoroquinolone therapy.
No long-term studies have been done among former users of
these antibiotics. Fibromyalgia-like symptoms have been associated with
fluoroquinolones, and some experts suggest that some cases of fibromyalgia may
result from treatment with a fluoroquinolone.
A half-dozen fluoroquinolones have been taken off the market
because of unjustifiable risks of adverse effects. Those that remain are
undeniably important drugs, when used appropriately. But doctors at the Centers
for Disease Control and Prevention have expressed concern that too often
fluoroquinolones are prescribed unnecessarily as a “one size fits all” remedy
without considering their suitability for different patients.
Experts caution against giving these drugs to certain
patients who face higher than average risks of bad reactions — children under
age 18, adults over 60, and pregnant and nursing women — unless there is no
effective alternative. The risk of adverse effects is also higher among people
with liver disease and those taking corticosteroids or nonsteroidal
anti-inflammatory drugs.
When an antibiotic is prescribed, it is wise to ask what the
drug is and whether it is necessary, what side effects to be alert for, whether
there are effective alternatives, when to expect the diagnosed condition to
resolve, and when to call if something unexpected happens or recovery seems
delayed.
At the same time, when an antibiotic is appropriately
prescribed, it is extremely important to take the full prescription as directed
and not to stop treatment when the patient simply begins to feel better.
A version of this article appeared in print on 09/11/2012,
on page D7 of the NewYork edition with the headline: A Cure That Can Be Worse
Than the Illness.
