sxyy66 发表于 2008-1-17 17:49:42

抗菌素抗性问题值得关注

Antibiotic resistance issues merit attention

Dec 1, 2007
By:John Jesitus
Dermatology Times (皮肤科时讯)

Buenos Aires, Argentina — Dermatologists should be mindful of the impact their prescribing habits have in potentially contributing to the emergence of antibiotic-resistant bacterial strains, particularly when it comes to chronic antibiotic use.

One expert advises minimizing antibiotic use to what is determined to be needed for a definitive therapeutic value, and to limit the duration of therapy whenever possible.

\"Dermatologists in the United States annually prescribe an average of 8 (million) to 9 million oral antibiotic prescriptions, and 3 (million) to 4 million topical antibiotic prescriptions,\" says James Q. Del Rosso, D.O., dermatology residency director at Valley Hospital Medical Center in Las Vegas.

Dermatologists frequently prescribe antibiotics for chronic treatment, a practice that is consistent currently with the standard of care.

However, Dr. Del Rosso says , \"It's important for dermatologists to consider how their antibiotic prescribing patterns may potentially be contributing to antibiotic resistance that in some cases may prove to be clinically significant. Although I do not want to be perceived as claiming that 'The sky is falling,' we must remain vigilant, as we face every day in practice patients who respond to the treatment of acne less favorably, or who present with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).\"

By their very nature, antibiotics contribute over time to natural selection of resistant strains of bacterial organisms.

\"As more sensitive organisms are eradicated by the antibiotic, less sensitive bacteria survive and replicate,\" Dr. Del Rosso says.

\"That goes not only for the bacteria you're treating, but also for all the other bacteria that the antibiotic is exposed to, especially with oral antibiotics,\" which impact bacteria throughout the entire body, he says.

Accordingly, he says treating acne with antibiotics can create antibiotic-resistant strains of Propionibacterium acnes and other microorganisms that could be associated with non-dermatological medical problems. For example, one study of acne patients receiving oral tetracycline showed that over time, the amount of Streptococcus pyogenes colonization in the oropharyngeal tract and the number of resistant organisms therein increased (Levy RM, et al. Arch Dermatol. 2003 Apr.139(4):467-71).

In this study, 85 percent of oropharyngeal flora in patients treated with tetracycline showed resistance to at least one agent, versus 20 percent of patients who had no antibiotics.

\"The clinical significance of these findings may be debated,\" he says. But the treatment clearly made patients ripe for developing or transferring conditions that dermatologists wouldn't necessarily see or treat, Dr. Del Rosso says.

\"Therefore,\" he says, \"we must be aware that when we prescribe antibiotics, we are changing the bacterial milieu. My suggestion is that we prescribe antibiotics when we believe they're absolutely necessary to treat the patient's condition.

\"I certainly use oral antibiotics and topical antibiotics for the treatment of acne, but I utilize them in combination with other agents, and ultimately attempt to transition the patient to a topical maintenance regimen.\"

When treating acne, he says, \"It's helpful to use benzoyl peroxide with antibiotics to reduce the emergence of P. acnes resistance.\"

Conversely, Dr. Del Rosso says, \"Rosacea is a disease where we conventionally use systemic antibiotics, but we don't have any proof that we're treating a bacterium.\"

Accordingly, he says, it is rational to initially treat rosacea, especially the inflammatory subtype, with anti-inflammatory therapies, often using a combination of a topical agent with anti-inflammatory dose doxycline.

\"If the patient fails an adequate trial of this approach,\" he says, \"then antibiotic therapy is reasonable.\"

Regarding CA-MRSA, he adds, \"We need to stay on top of the treatment of these organisms because they're becoming more rampant.\"

While physicians can contain most CA-MRSA cases, some are virulent, Dr. Del Rosso says.

\"We must be aware of our antibiotic prescribing, because we don't want to lose the sensitivity of these organisms to some of the antibiotics that we have,\" particularly since the process of developing new antibiotics is very slow and uncertain.

Overall, he says, \"Dermatologists must be at the forefront of staying on top of changes in resistance patterns and trying to minimize our contribution to resistance as best we can.\"

Furthermore, he says dermatologists can't simply assume that because they've been using antibiotics for years, they're not contributing to potential resistance problems.

\"We wouldn't know if we were contributing to a problem because resistance can take time to develop. And some of the problems that are created do not typically present to dermatologists,\" Dr. Del Rosso says.

Because dermatologists commonly prescribe oral and topical antibiotics, frequently for chronic use in diseases such as acne and rosacea, Dr. Del Rosso adds, \"It is very important that dermatologists remain aware of emerging patterns of resistant organisms — and be open-minded to modifying prescribing patterns if it's proven that clinically significant dermatologic conditions or other infections may be associated with those prescribing patterns.

\"Over time, we will learn more about this, as new information comes forward.\"

Disclosure: Dr. Del Rosso is a consultant, researcher and speaker for multiple manufacturers of topical and systemic antibiotics.

http://www.dermatologytimes.com/dermatologytimes/article/articleDetail.jsp?id=476454&pageID=1&sk=&date=
因为皮肤科医生常常为慢性疾病,如痤疮和酒渣鼻,开具长期使用的口服和外用抗生素处方,Del Rosso博士补充说,“非常重要的是,皮肤科医生需保持对微生物抗药性发生模式的认识,如果处方模式被证明与临床上的重大皮肤科疾病或其他感染有相关性,需以开明的态度进行修改。
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