Antibiotics

Antibiotic Misuse in Hospitals Raises Patient Infection Risk

More than half of hospitalized patients receive antibiotics, but these prescriptions may often be inappropriate — for example, giving patients the wrong medicine or leaving them on a drug for too long, according to a new report from the Centers for Disease Control and Prevention.

These prescriptions can put patients at risk for serious complications, including developing the deadly bacterial infection Clostridium difficile, according to the report.

In 2010, nearly 56 percent of hospitalized patients were prescribed antibiotics at some point during their stay, according to the report, which reviewed information from more than 300 U.S. hospitals.

But for about one-third of prescriptions for urinary tract infection (UTI), the researchers found evidence of prescribing errors: antibiotics were given without proper testing or evaluation for a UTI, or given for too long, the report found. (UTI is one of the most common conditions for which antibiotics are prescribed

In addition, an analysis of medical-surgical wards at selected hospitals showed that antibiotic use at some of these hospitals was three times higher than at other hospitals, a finding that suggests hospital prescribing practices can be improved, the CDC said.

The report found that patients who received powerful antibiotics (so-called board spectrum antibiotics) were three times more likely to get the notoriously difficult to treat diarrheal disease Clostridium difficile compared to patients who did not receive antibiotics.

The CDC estimates that reducing use of broad-spectrum antibiotics by 30 percent would lead to a 26 percent decrease in C. difficile infections. There are about 250,000 C. diff infections in hospitalized patients each year, and about 14,000 people in the U.S. die yearly from C. diff infections, CDC statistics show.

Inappropriate prescribing of antibiotics also contributes to other antibiotic-resistant infections, a growing problem in U.S. hospitals, the CDC said.

“Antibiotics are often lifesaving; we have to protect them before our medicine chests run empty,” Dr. Tom Frieden, director of the CDC, told reporters today (March 4). “The drugs we have today are endangered, and any new drugs we get could be lost just as quickly if we don’t improve the way we prescribe and use them,” Frieden said.

The CDC recommends that every hospital implement a program to help improve antibiotic prescribing.

Such programs would include a way to monitor prescribing practices and antibiotic-resistant infections. The CDC also recommends that physicians who prescribe antibiotics reassess their patients after 48 hours to see whether the dose, duration or type of drug should be changed, Frieden said.

The CDC estimates that implementing these programs could reduce the rate of C. difficile infection by half over a five-year period, Frieden said.

The report will be published on Friday (March 7) in the CDC’s Morbidity and Mortality Weekly Report.

Source: Live science

 

Promising class of antibiotics discovered for drug-resistant TB

St Jude Children’s Research Hospital scientists have discovered a promising new class of antibiotics that could aid efforts to overcome drug-resistance in tuberculosis (TB). The drugs increased survival of mice infected with TB and were effective against drug-resistant strains of TB. St Jude led the international research effort, results of which appear in the journal Nature Medicine.

The antibiotics, called spectinamides, were created by changing the chemical structure of an existing antibiotic, spectinomycin, which does not work against TB.

In multiple trials of mice with both active and chronic TB infections, researchers report that one version of the new drug—an analogue known as 1599—was as good as or better than current TB drugs at reducing levels of the bacteria in the lungs of mice. In addition, 1599 caused no serious side effects.

“This study demonstrates how classic antibiotics derived from natural products can be redesigned to create semi-synthetic compounds to overcome drug resistance,” said corresponding author Richard Lee, a member of the St Jude Department of Chemical Biology and Therapeutics. “I hope the result will be drugs that are more effective against tuberculosis and offer a faster route to a cure with fewer side effects.”

TB remains a leading cause of global illness and death. The latest data from the World Health Organization estimates that TB kills 1.3 million persons annually and sickens 8.6 million worldwide. Current treatment requires months of multi-drug therapy to eradicate the slow-growing bacterium, which can lie dormant for years without causing symptoms and results in hard to treat chronic or latent infections. The rise of multi-drug resistant TB, including strains reportedly resistant to all available medications, has further complicated treatment.

This new class of antibiotics works against TB by disrupting the function of a part of the cell known as the ribosome, which is responsible for protein synthesis. To do that, the spectinamides bind to a particular site on ribosomes that is not shared by other TB drugs. That allows the drug to be used in combination with other medications.

For this study, researchers used an approach called structure-based design to re-engineer how spectinomycin binds to the ribosome. To guide their design efforts, scientists used a 3-D model that provided an atomic-level view of spectinomycin bound to the tuberculosis ribosome. The study reinforces the potential of structure-based design as a tool for designing other new agents to block mechanisms TB and other bacteria use to resist current antibiotics, Lee said.

The research reports on the first 20 of the more than 120 spectinomycin derivatives that have resulted from the effort. The list includes 1599 and two other analogues tested against TB in mice.

The three analogues not only bound the ribosome tightly, but they were more successful at avoiding a TB resistance mechanism called efflux. The TB bacteria use efflux pumps as a strategy to remove drugs and other threats from the cell before they can work against the bacteria. Efflux pumps, however, did not protect TB against spectinamides.

The drugs were also effective against multi-drug-resistant strains of TB growing in the laboratory. The strains had been isolated from patients with the disease.

Researchers also found no evidence that 1599 or the two other analogues tested interfered with normal functioning of human cells. Preliminary safety testing on cells grown in the laboratory showed the drugs were not toxic to mammalian cells because they only inhibit the bacterial ribosomes and not mammalian ribosomes.

Work is underway now in mice combining 1599 with new or existing TB drugs. The goal is to identify multi-drug therapy to try in a clinical trial of patients with drug-resistant TB.

Source: India medical Times

U.S. issues rules for removing antibiotics from farms

In response to concerns about the rise in drug-resistant super bugs worldwide, US regulators issued voluntary guidelines to help cut back on antibiotics routinely fed to farm animals.

The plan described by the Food and Drug Administration is not mandatory, and applies only to certain pharmaceuticals that are given to healthy livestock in a bid to grow bigger animals and boost food production.

“We need to be selective about the drugs we use in animals and when we use them,” said William, deputy director Flynn yesterday for science policy at the FDA’s Centre for Veterinary Medicine.

“Antimicrobial resistance may not be completely preventable, but we need to do what we can to slow it down.”

The FDA guidelines set out a three-year timeframe for phasing out the use of antibiotics that are important in human medicine for growth uses in farm animals.

Companies that make animal feed containing antibiotics would be restricted to marketing them only for sick animals.

The medicines would also have to be administered or prescribed by a veterinarian with a view to preventing or controlling disease.

The World Health Organisation says inappropriate use of antimicrobial medicines in farm animals is one the factors underlying the spread of drug-resistant infections in people, including tuberculosis, malaria and gonorrhea.

Other factors include people’s failure to complete the full doses of antibiotics when sick and the lack of a coordinated global response to dangerous illnesses.

Consumer advocates say 80 percent of antibiotics sold in the United States are destined for use in livestock, so leaving the responsibility in the hands of business is a mistake.

Louise Slaughter, the only microbiologist in Congress, described the FDA’s voluntary guidance as “an inadequate response to the overuse of antibiotics on the farm with no mechanism for enforcement and no metric for success.”

This guidance “falls woefully short of what is needed to address a public health crisis,” she added in a statement.

Source: the Japan Times

New guidance limits antibiotics for common infections in children

Every year, as many as 10 million American children are at risk for side effects from prescribed antibiotics that most likely won’t help them get over an upper respiratory infection, according to the U.S. Centers for Disease Control and Prevention (CDC).

Many of these upper respiratory infections are caused by viruses, which are not helped by antibiotics.

“Our medicine cabinet is empty of antibiotics to treat some infections,” said CDC Director Tom Frieden, M.D., M.P.H. in a press release. “If doctors prescribe antibiotics carefully and patients take them as prescribed we can preserve these lifesaving drugs and avoid entering a post-antibiotic era.”

The overuse of antibiotics, a significant factor fueling antibiotic resistance, is the focus of a new report Principles of Judicious Antibiotic Prescribing for Bacterial Upper Respiratory Tract Infections in Pediatrics by the American Academy of Pediatrics (AAP) in collaboration with the CDC.

The new report was released to coincide with Get Smart About Antibiotics Week which runs from November 18 – 24.

The AAP has outlined responsible antibiotic prescribing for three common upper respiratory tract infections in children:

• Ear infections
• Sinus infections
• Sore throats

“Many people have the misconception that since antibiotics are commonly used that they are harmless,” said co-author of the report Dr. Lauri Hicks in a press release. “Taking antibiotics when you have a virus can do more harm than good.”

Antibiotic resistance occurs when bacteria evolve and are able to outsmart antibiotics, making even common infections difficult to treat.

Each year more than two million Americans get infections that are resistant to antibiotics and 23,000 die as a result, according to a CDC report from September 2013.

AMA recommendation for clinicians: 3 Principles of Responsible Antibiotic Use

1. Determine the likelihood of a bacterial infection: Antibiotics should not be used for viral diagnoses when a concurrent bacterial infection has been reasonably excluded.

2. Weigh benefits versus harms of antibiotics: Symptom reduction and prevention of complications and secondary cases should be weighed against the risk for side effects and resistance, as well as cost.

3. Implement accurate prescribing strategies: Select an appropriate antibiotic at the appropriate dose for the shortest duration required.

Source: health2fit