Campaigns aimed at cutting back the overuse of antibiotics in the United States may be working, as research showed that U.S. doctors prescribed fewer unnecessary antibiotics in the 1990s.

However, when a drug is necessary doctors are now more likely to prescribe expensive, “broad-spectrum” antibiotics. The use of such antibiotics doubled in the past decade.

Broad-spectrum antibiotics are useful to fight certain bacteria that are often the cause of severe infections and cannot be treated by narrow-spectrum antibiotics. These types of bacteria are usually not involved in the common respiratory tract infections treated in doctor’s offices.

As of 1999, broad-spectrum antibiotics accounted for close to half of antibiotics prescribed to adults and 40 percent of those prescribed to children, according to research.

As with the overuse of antibiotics to fight specific bacteria, the overuse of broad-spectrum antibiotics can cause bacteria to become resistant to the drugs. More efforts are needed to persuade doctors to not over-prescribe broad-spectrum antibiotics, according to researchers.

In the study, researchers examined data on doctor visits from 1991 to 1992, 1994 to 1995 and 1998 to 1999.

Visits that resulted in an antibiotic prescription dropped from 13 percent to 10 percent for adults and from 33 percent to 22 percent for children.

However, the use of broad-spectrum agents increased from 24 percent to 48 percent of antibiotic prescriptions in adults and from 23 percent to 40 percent in children, according to the report.

The average cost for broad-spectrum drugs, which include Zithromax, Biaxin, quinolones and Augmentin, was over $50 for a seven-day supply in 1999, compared with less than $5 per seven-day course for some narrow-spectrum drugs.

Although antibiotics only fight bacteria, not colds, which are commonly caused by a virus, from 1998 to 1999 22 percent of adults and 14 percent of children who were prescribed a broad-spectrum antibiotic received one to treat a common cold or other viral infection.

The increasing reliance on broad-spectrum antibiotics could lead to a new crisis in antibiotic resistance, according to researchers.

Annals of Internal Medicine April 1, 2003;138:525-533,605-606

Source: www.mercola.com