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ANTIBIOTICS

November 10, 2004

Antibiotics (drugs used to treat bacterial infections) are overwhelmingly misprescribed in the United States. Despite congressional hearings and numerous academic studies on this issue, it has become the general consensus that 40 to 60% of all antibiotics in this country are misprescribed. New studies continue to confirm the fact that a large proportion of antibiotic prescribing for both children and adults continues to be inappropriate.[1],[2] To put it simply, a large proportion of...

Antibiotics (drugs used to treat bacterial infections) are overwhelmingly misprescribed in the United States. Despite congressional hearings and numerous academic studies on this issue, it has become the general consensus that 40 to 60% of all antibiotics in this country are misprescribed. New studies continue to confirm the fact that a large proportion of antibiotic prescribing for both children and adults continues to be inappropriate.[1],[2] To put it simply, a large proportion of antibiotics are prescribed in situations in which the infection cannot be treated by any antibiotic, or another, more effective and appropriate antibiotic should be used instead. This should be a major concern, since the misprescribing of antibiotics poses some real dangers to the population at large, as well as to the individuals taking them, especially older adults.

Widespread Misprescribing of Antibiotics

Colds and Bronchitis

Two recently published studies, based on nationwide data from office visits for children and adults, have decisively documented the expensive and dangerous massive overprescribing of antibiotics for conditions that, because of their viral origin, do not respond to these drugs. Forty-four percent of children under 18 years old were given antibiotics for treatment of a cold and 75% for treatment of bronchitis. Similarly, 51% of people 18 or older were treated with antibiotics for colds and 66% for bronchitis. Despite the lack of evidence of any benefit for most people from these treatments, more than 23 million prescriptions a year were written for colds, bronchitis, and upper respiratory infections. This accounted for approximately one-fifth of all prescriptions for antibiotics written for children or adults.[1],[2]

Sore Throats

Sore throats are one of the leading causes of visits to doctors, with more than 10 million such visits a year. The only kind of sore throat that merits treatment with an antibiotic is a bacterial sore throat caused by group A beta-hemolytic streptococci, the so-called strep throat. Although only approximately 10% of adults seen by a doctor for a sore throat actually have a strep throat, 75% of patients with sore throats seen by doctors are prescribed an antibiotic.[3] Though the likelihood that a sore throat in a child is a strep throat is somewhat higher, perhaps 25%, the majority of children are also treated with antibiotics.

Bladder Infections

In a recent study of more than 13,000 women going to a doctor because of a bladder infection, more than 95% of whom had an acute bladder infection, not a recurrent one, only 37% were prescribed the preferred treatment for this condition, the combination antibiotic trimethoprim/sulfamethoxazole (sometimes prescribed by the brand name Bactrim or Septra. Almost as many (32%) were prescribed one of the heavily promoted fluoroquinolones such as ciprofloxacin (CIPRO), which are not the first-choice drug for bladder infections. Using such drugs when there is a better alternative contributes to the rapidly increasing and health-threatening problem of resistance to antibiotics, whereby when the fluoroquinolones are actually needed, people may be infected with bacteria that are resistant to them (see below). The recommended duration of treatment for an acute bladder infection is three days of the antibiotic, and yet less than 10% of the prescriptions were for three days. The most common duration of treatment was 10 days, followed by seven and five days. Thus, in addition to using the wrong antibiotic most of the time, the duration of therapy was too long most of the time.[4]

FDA WARNING ON UNNECESSARY ANTIBIOTIC PRESCRIBING

To reduce the development of drug-resistant bacteria and maintain the effectiveness of this anti-bacterial drug product and other antibacterial drugs, this drug product should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antimicrobial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. Prescribing this antibacterial drug product in the absence of a proven or strongly suspected bacterial infection [for] a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

Problems from Misuse of Antibiotics

The problems resulting from misuse are adverse effects from the drugs, exposure to additional complications from ineffective treatment of an infection, and bacterial resistance to antibiotics. In addition, misprescribing is a waste of money.

Adverse Effects

Although the numbers of adverse effects and problems with antibiotics are often low compared with other drugs, there are still some serious adverse effects that can occur. For example, an allergic reaction to penicillin can cause death, although this is uncommon. Use of antibiotics taken by mouth can cause stomach irritation and diarrhea, which can progress to a more severe condition caused by intestinal bacteria that are difficult to kill.

Other antibiotics can cause problems with the liver and kidneys, which is a real concern when prescribing for older adults. The best way to avoid these adverse effects is not to use antibiotics unless they are indicated and to avoid especially dangerous ones whenever possible. This is not the current practice, however.

Chloramphenicol (CHLOROMYCETIN), for example, is one antibiotic that has a particular danger. In rare instances, this drug can cause irreversible bone marrow depression, which can be fatal. In 1983, 49% of all prescriptions of chloramphenicol were for conditions in which the drug was clearly not indicated, such as tonsillitis and infection prevention after surgery. This meant that half the prescriptions for chloramphenicol unnecessarily exposed people to a serious danger. Now, fortunately, it is rarely used.

A literature synthesis found some evidence that patients taking rifampin and using oral contraceptives may experience a drop in the effectiveness of their oral contraceptives. [5]. It is therefore advisable to use an alternative or additional form of contraception if you have to take rifampin and are using oral contraceptives. There is weaker, but not conclusive, evidence for such an association with the penicillins and tetracyclines. Evidence for an association with other antibiotics is weaker still. It is difficult to distinguish between typical rates of oral contraceptive failure and possible lowered oral contraceptive effectiveness due to taking antibiotics.

Exposure to Additional Complications

As discussed above, antibiotics are often misused to treat the common cold, flu, or other acute respiratory illnesses that should not be treated with any antibiotic. Since both the cold and the flu are caused by viruses, there is absolutely no possible way antibiotics can help cure these diseases or speed up the natural cure. They can, however, make a person more susceptible to a dangerous bacterial superinfection, such as pneumonia, which could be resistant to the antibiotic the person is taking. Patients should not insist that their doctors prescribe antibiotics for trivial conditions such as colds.

Other microorganisms that are not killed by the antibiotics can cause an infection, such as candidiasis, a fungal infection. Oral candidiasis is fairly common in older adults who wear dentures. A sore mouth or tongue, or soreness of the vagina, are possible symptoms.

Bacterial Resistance

This is becoming an ever-expanding problem. After antibiotics are used for a period of time, certain bacteria develop methods that enable them to become resistant to some antibiotics. The resistant bacteria are the ones that survive after antibiotic treatment, and over time they become the dominant force via a process of natural selection.

In a current campaign to educate doctors and the public about the seriousness of the problem of antibacterial resistance, the Federal Centers for Disease Control has published these worrisome statistics:

Drug-resistant pathogens are a growing threat to all people, especially in health care settings.

  • Each year nearly 2 million patients in the United States get an infection in a hospital.
  • Of those patients, about 90,000 die as a result of their infection.
  • More than 70% of the bacteria that cause hospital-acquired infections are resistant to at least one of the drugs most commonly used to treat them.
  • Persons infected with drug-resistant organisms are more likely to have longer hospital stays and require treatment with second- or third-choice drugs that may be less effective, more toxic, and/or more expensive.[6]

For example, the staphylococcus, a common bacterium causing skin infections, used to be exquisitely sensitive to penicillin when the drug was first introduced. Twenty years later, penicillin was no longer anywhere near as effective against the staphylococcus. A new drug, called methicillin, was designed to combat the “staph bug,” and it was widely used. Over time, strains of methicillin-resistant “super-staph” (MRSA) have also emerged.

At a recent government-sponsored conference on antibiotic resistance, some alarming data were presented on the rapid rise in resistance to antibiotics of some common bacterial causes of life-threatening illness and death. For example, the odds that staph aureus will be resistant to a once extremely useful antibiotic, methicillin (MRSA), have increased from about 4% in 1980 to over 55% in 2000. Thus, clearly related to the wanton misprescribing of antibiotics to people who do not have bacterial infections or the wrong antibiotic to those who do have infections (see p. 673), there has been a more than 13-fold increase in resistance. For another common cause of bacterial illness and death, enterococcus, resistance of vancomycin (VRE) has increased from about 1% in 1988 to about 27% in 2000, a 27-fold increase.[7]

The consequences of increased bacterial resistance to antibiotics are very serious: infections with staph aureus resistant to methicillin (MRSA) can cause ventilator-assisted pneumonia, and blood infections associated with catheters in people in intensive care units (ICUs). In ICU patients, infections with VRE are taking the form of abdominal or blood infections. The authors of this review on the impact of antibiotic resistance summarized the possible outcomes caused by antibiotic-resistant organisms:[8]

  • increased mortality
  • prolonged length of hospital stay
  • need for more costly therapy and management
  • medical complications

These examples illustrate that newer, improved antibiotics are not the final answer to bacterial resistance. If new antibiotics are developed but then overused, bacteria will find new ways to develop resistance, rendering those drugs ineffective.

Many bacteria in the hospital setting have now become resistant to multiple antibiotics, and, as a result, infections with these bacteria have become a very dangerous occurrence. The only way to help stop the development of bacterial resistance is by discouraging the gross misuse and overuse of antibiotics. It makes sense to use these “magic bullets,” especially the newer ones, only when necessary so that their power will still be effective when it is truly needed.

Thus, there are both dangers and benefits to antibiotics. When you have an infection that can be cured with the proper antibiotic, the benefit of taking the drug is much, much greater than its dangers. But since there are dangers, there are compelling reasons to avoid unnecessary use of antibiotics and to select the safest and most effective ones.

Avoiding Unnecessary Use of Antibiotics

There are several basic principles that should be followed in determining the correct antibiotic:

  1. Establish 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. (Although there has been some heartening progress in the development of specific antiviral agents such as amantadine and acyclovir, ribavirin, AZT, and other drugs for HIV infections, viral infections, for the most part, cannot be treated with drugs.)
  2. Choose the correct antibiotic. It must be effective against the most likely organisms that can cause your infection. In our drug profiles on individual antibiotics, we state the types of infections for which each antibiotic is best suited.
  3. Take a culture before using an antibiotic. A culture should be taken from the site where you have an infection, such as your throat, sputum, 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 find out that you do not have an infection and do not require antibiotics.
  4. Consider the cost of the antibiotic. This should be done when everything else is equal. If several antibiotics are equally effective, their cost should be taken into consideration when selecting a drug to use. Newer drugs on patent are much more expensive than older antibiotics that have been on the market for some time. For example, the oral cephalosporin cefuroxime (CEFTIN) is often used to treat urinary tract infections. There is no advantage to using this drug instead of a generic drug such as trimethoprim and sulfamethoxazole. Cefuroxime, however, costs 12 times as much for two weeks of treatment.[9] Clearly, in the case of a simple infection, the less expensive drug for the shorter period of time is preferred as an initial choice.

The Importance 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, however. 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 will not be completely eliminated and can quickly multiply, causing another infection. This infection may then be resistant to the original antibiotic.

In general, antibiotics taken by mouth are preferred if you do not require hospitalization and can take the pills without any problem. There is usually no advantage to having an injection of an antibiotic except in certain clinical situations.

Newer Versus Older Antibiotics

Remember, newer antibiotics are more expensive than the older ones. They should be used only when an advantage can be shown over older antibiotics—for example, if the new antibiotic is more active against resistant bacteria.

In summary, antibiotics can make a world of difference when the right antibiotic is chosen for the right situation. Unfortunately, in the United States and most of the rest of the world today, this is only being done a minority of the time. Questioning your doctor about why he or she is prescribing an antibiotic is a step in the right direction toward safer and better antibiotic use.