the pharmacist's role in promoting optimal antibiotic therapy
Is it a bird? Is it a plane? No, it's Superbug! In another battle waged against the superbug, the superbug seems to have defeated one of the newest antibioticslinezolid (Zyvox, Pharmacia).
A letter published in the April 14 issue of The Lancet reports on suspected vancomycin-resistant Enterococcus faecium (VRE) resistant to linezolid. While the resistance is limited to VRE in very seriously ill patients, it showcases the escalating antibiotic resistance dilemma.
Pharmaceutical companies are taking many steps to address this issue. One way, naturally, is to continue to develop new antibiotics. In that arena, Aventis Pharmaceuticals' investigational antibiotic, telithromycin (Ketek), has been recommended for Food & Drug Administration approval by an advisory panel.
Telithromycin, the first of a new antibiotic family known as ketolides, is essentially an engineered version of a macrolide. It has been developed specifically to provide improved protection against Streptococcus pneumoniae, especially resistant strains, with a once-daily regimen. One of the phase III study investigators for telithromycin, Tom File, remarked in a company press release that the agent's short and easy regimen should also help combat resistance. He added that many patients stop taking their drugs when they feel better, which can lead to resistance since the bacteria are usually not fully eradicated.
But new antibiotics are not the only solution to the growing epidemic of antibiotic resistance. As battles are lost against these flourishing superbugs, collaboration is needed from all sectors of the health-care system in implementing effective strategies to improve antibiotic use and prevent a "postmicrobial era" in which the antimicrobials are no longer useful. Pharmacists can play a major role through clinician and patient education and focused clinical services.
Ortho Pharmaceuticals, in its continuing efforts to promote optimal antibiotic use, recently held a press briefing entitled "Antibiotic Resistance in the U.S. Today: Issues and Answers." The following case studies were presented. One of the roles of the pharmacist on a health-care team is to recommend antibiotic regimens and courses to providers (in a health-care system) or to patients (in a community setting). Take a look at the cases below and see how you would respond in each case.
Case 1: A 19-year-old college student presents to the clinic with a cough, fever, and muscle aches she has had for two days. She has no medical problems and is not taking any medications. A few other residents in her dormitory have also been ill in the past few days. Is an antibiotic necessary for this student?
Case 2: A 42-year-old female who has a child in day care complains of a fever, cough, and chest pain. She has pneumonia identified by X-ray. How should she be treated, and what role does antibiotic resistance play here?
Case 3: A 62-year-old smoker with chronic bronchitis is now experiencing increased shortness of breath and coughing up more sputum. This patient had one episode of respiratory failure last year, requiring mechanical ventilator therapy. What role does resistance play here?
The first step for the health-care team would be to differentiate a viral infection from a bacterial infection. According to Robert Siegel, M.D., "most bacterial infections will not spread person-to-person." So if there are other people in the familyor, as in Case 1, the dormitorywho are also sick, there is a good chance that the infection is viral.
Siegel is director of the Critical Care Center and associate chief of pulmonary service at Bronx Veteran's Affairs Medical Center in New York. Although Siegel wouldn't recommend an antibiotic for the patient in Case 1, he would keep in mind that a viral infection can predispose a patient to a bacterial infection several days later because the immune system can become "overwhelmed" by the virus.
In Case 2, Siegel recognized that "not only are the children who are in day care more likely to have resistant organisms, but the parents of children in day care are also more likely to have resistant organisms." He would, therefore, be concerned that this patient may have penicillin-resistant pneumococcus and would have to decide, based on susceptibility data for the area, whether to use a macrolide or fluoroquinolone for this patient.
It gets even more complicated in Case 3. "I certainly have to worry here about the underlying illness and the risk of failure. If there is a resistant organism, this patient may end up in the intensive care unit," declared Siegel. Taking into consideration the cost of failure both on the personal level for the patient and the high cost of hospitalization, he said he would not treat this patient with anything but a fluoroquinolone.
Many health groups are initiating plans to combat the growing epidemic of antibiotic resistance. An international panel of public health experts recently gathered in San Francisco for the 30th International Educational and Scientific Symposium of the Society of Critical Care Medicine. During the symposium, the medical experts identified the steps, outlined in the box below, that all health-care professionals can take to decrease antimicrobial resistance.
The panel noted that the treatment of respiratory infections serves as a good illustration in identifying antibiotic overuse. Every year, nearly 80 million antibiotic prescriptions are written for patients in the United States, and some estimates suggest that half of these may not be necessary. Pharmacists can be actively involved in patient education in these instances, providing information on management of self-limiting illness and supporting physicians in withholding prescriptions.
More recently, the nation's largest health insurers unveiled a concerted strategy to combat the superbug. The groupthe Coalition for Affordable Quality Health Care (CAQH)will partner with the Centers for Disease Control & Prevention to educate physicians and patients about the dangers of overprescribing antibiotics.
Tammy Chernin. Those thriving superbugs are at it again.