Do shorter courses of antibiotics work?

Possible benefits include lower costs and increased patient compliance, but some worry that the practice may cause more adverse events and is not always appropriate.

By Victoria Stagg Elliott, amednews staff. Jan. 21, 2002.

Infectious disease experts are increasingly debating the merits of higher doses of antibiotics over a shorter period of time.

Uncomplicated urinary tract infections could be treated in three days rather than seven. Sinusitis could be handled in seven days instead of 10. Typhoid treatment could be as short as two days, according to a paper presented by Ethan Rubinstein, MD, head of infectious diseases at the Chaim Sheba Medical Center at Tel Aviv University in Israel, during last month's Interscience Conference on Antibiotics and Chemotherapy in Chicago.

Links

"We need to hit them early and hit them hard," said Dr. Rubinstein. "We are trying to find the minimal effective antibiotic duration that will still afford a complete cure."

Advocates say shorter courses may save money, shorten inpatient treatment and make patients more likely to take their meds. Higher doses may kill more bacteria faster and, most importantly, may be a possible solution to the emergence of resistance.

"The concept is very good. Giving a high concentration over a short course would not allow for the heavy growth of a subpopulation of resistant bacteria," said Philip Tierno, PhD, director of diagnostic microbiology and immunology at the New York University Medical Center and Mount Sinai Medical Center. "It would knock out the susceptible form, and the immune response could then eradicate those few organisms that might be resistant."

The trend toward shorter courses has also received official green lights. In November 2001, a Food and Drug Administration advisory committee endorsed a single-dose and three-day treatment regimen of azithromycin for acute otitis media. The drug was approved in 1992 for five days. The agency also approved a five-day regimen, down from seven, of gatifloxacin for exacerbation of chronic bronchitis.

Higher doses of antibiotics could cause more side effects.

But not everyone is sold on the concept, and some question whether the approach will deliver all that its advocates say it will. A shorter course may not completely kill the infection and may not always lower costs, particularly since hospital stays have already been shortened through the use of at-home IV therapy.

Some antibiotics are also toxic at the higher doses, and there is significant concern that higher doses could produce more side effects. The one-dose course of azithromycin for otitis media, for example, induced vomiting in 10% of pediatric patients.

"How long after a child vomits do you need to redose, and who will pay for it?" said Tina Tan, MD, a pediatric infectious disease specialist at Children's Memorial Hospital in Chicago. "The insurance companies might pay for a single dose, but they are probably not going to pay for another dose."

The short-course phenomenon is most likely to affect 10-day or two-week antibiotic courses. Experts also warn that a shorter course would not be appropriate for tuberculosis or bacterial meningitis. "We know that with those infections you cannot short-course if you want to effectively cure the infection," said Dr. Tan. "The short-course therapy is really for more localized infections."

Experts on both sides of the issue concede that determining length of treatment has always been a bit woolly, and that much more research is needed to determine optimal regimens.

"Duration of therapy is very soft to begin with. It's not based so much on science as it is on opinion," said Randolph Regal, PharmD, clinical pharmacist at the University of Michigan Hospital. "We need scientific information that short courses are beneficial over the more traditional courses."