Inappropriate Prescribing Of Fluoroquinolone Antibiotics, Ciprofloxacin (CIPRO), Gatifloxacin (TEQUIN), And Others

The April 2003 issue of Worst Pills, Best Pills News carried a major article on the growing problem of bacteria resistance to antibiotic treatment and what it means to patients and the healthcare system. A major factor contributing to the rapid increase in the U.S. and elsewhere of antibiotic resistance is inappropriate prescribing and the extent of the inappropriate prescribing of antibiotics is staggering. The Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics estimated in a report published in the journal Pediatrics in 1998 that half of the 100 million antibiotic prescriptions a year written in physicians’ offices in the U.S. are unnecessary because they are prescribed for the common cold and other viral infections, against which antibiotics are ineffective.

In this month’s newsletter we cover research from the University of Pennsylvania in the March 10, 2003 Archives of Internal Medicine that found, not surprisingly, that “Inappropriate FQ [fluoroquinolone] use in EDs [emergency departments] is extremely common.”

This study was supported in part by the Centers for Education and Research of Therapeutics (CERTs) through the federal Agency for Healthcare Research and Quality. The CERTs program was set up by Congress to fund independent research to answer questions that pharmaceutical industry supported research tends to avoid, such as examining the inappropriate prescribing of drugs.

The table appearing at the end of this article lists the 11 fluoroquinolone antibiotics marketed in this country since 1986. The table also indicates which fluoroquinolones have come off the market for safety reasons and which of these drugs we consider as Do Not Use drugs.

In this study, the researchers evaluated 100 consecutive patients who went to the emergency room and received a prescription for a fluoroquinolone antibiotic. Of the 100 patients, 81 (81%) received a fluoroquinolone antibiotic for an inappropriate use. In 43 (53%) of these patients, a fluoroquinolone was found inappropriate because another antibiotic was considered first-line treatment, and in 27 (33%) patients there was no evidence of an infection and therefore no indication for the use of any antibiotic. In the remaining 11 patients, there was insufficient evaluation by emergency room physicians to know if an antibiotic was needed or not.

Of the 19 patients that received a fluoroquinolone antibiotic for an appropriate use, only one patient was prescribed for the correct length of treatment and at the right dose.

These results with the fluoroquinolone antibiotics are troubling for several reasons. First, this family of antibiotics is first-line treatment for a relatively small number of infections. Second, of the 11 members of this family of antibiotics sold in the U.S. since 1986 (see table below), three have been removed from the market in this country or other countries for safety reasons (27%). These three drugs are temafloxacin (OMNIFLOX), grepafloxacin (RAXAR), and trovafloxacin (TROVAN). In addition, we have listed three fluoroquinolones, gatifloxacin (TEQUIN), moxifloxacin (AVELOX), and sparfloxacin (ZAGAM), as DO NOT USE drugs. Articles about gatifloxacin and moxifloxacin appear in the July 2002 and April 2001 issues of the newsletter respectively. Sparfloxacin is covered in the 1999 edition of the book Worst Pills, Best Pills. Our major concern with these three fluoroquinolones is their effect on electrical conduction in the heart that may lead to potentially life threatening heart rhythm disturbances.

The major safety problems that have been associated with the fluoroquinolone antibiotics other than the tendon toxicity and adverse effects on the heart mentioned above are neuropsychiatric adverse effects and phototoxicity (skin toxicity due to light or sun).

In spite of the problems that have been associated with the use of this family of antibiotics, and their role in therapeutics, four fluoroquinolones were in the Top 200 drugs dispensed in the U.S. in 2002. These drugs are ciprofloxacin, levofloxacin, gatifloxacin, and moxifloxacin and they accounted for almost 30 million prescriptions and approximately $2.5 billion dollars in sales.

When an antibiotic is prescribed inappropriately, for example for the common cold, there is no chance that the patient will benefit because antibiotics are ineffective against this illness. The patient faces only the risk of the antibiotic and in the case of the fluoroquinolone antibiotics the risk are substantial and can be serious.

Several rules must be followed to ensure that a specific antibiotic is prescribed properly:

1. It must be established that an antibiotic is necessary. This means that your infection has to be the type that can be effectively treated by an antibiotic. Antibiotics are used specifically to treat bacterial infections. Antibiotics do not treat viral infections, such as the common cold.

2. The correct antibiotic must be chosen. It must be effective against the most likely organisms that can cause your infection.

3. A culture must be taken before using an antibiotic. A culture should be taken from where you have an infection, such as your throat, urine or blood, and then grown to determine the specific organism that is causing your infection and whether it is susceptible to the preferred antibiotic. For example, if you have a urinary tract infection, the doctor should take a urine specimen and send it for culture before treating your infection. This does not mean that your infection cannot be treated right away, only that a culture is sent before you start antibiotics. In this way, if your infection persists, your doctor can determine which alternative antibiotic can be used against the bacteria. Your doctor may alternatively find out that you do not have an infection and do not require antibiotics.

A final crucial point that we covered in the first edition of the book Worst Pills, Best Pills and with each succeeding edition is the importance, in general, of completing a full course of therapy. It is important with any antibiotic to take the entire amount of the drug that your doctor prescribes. Often, after the first few days of taking antibiotics, you will begin to feel better. Perhaps you think that you do not have to finish your course of treatment since you are, after all, feeling healthy. This is not the case. The length of the regimen that your doctor prescribes for you is designed to eliminate all of the bacteria that are causing your illness. If you do not take all of your medication, the bacteria may not be completely eliminated and can quickly multiply, causing another infection. This infection may then be resistant to the original antibiotic.

What You Can Do

You should only be taking an antibiotic if there is a likelihood that the infection is caused by a bacterium. Antibiotics are ineffective against viral infections such as the common cold.