Pentagon Official Lays Out Post-Exposure Anthrax Treatment

by Catherine MacRae

Inside The Pentagon

April 27, 2000

While a post-exposure anthrax treatment involving a month-long course of antibiotics and vaccine has been shown by the Pentagon's own scientific research to be nearly 100-percent effective in preventing occurrence of the disease in persons treated immediately after exposure, a Pentagon official says the logistical difficulties of detecting an exposure to an individual or population means the antidote cannot be considered an alternative to the Pentagon's controversial vaccination program.

"So we tend to keep that in our pockets," the official told Inside the Pentagon, noting the post-exposure treatment -- indoctrinated in Defense Department policy -- is not often openly discussed by the Pentagon.

The Defense Department divides treatment for personnel exposed to anthrax into two categories: detected exposure and signs of disease. Patients in the first category -- suffering no symptoms -- are treated with the antibiotic and vaccine regimen.

However, this treatment is costly, the official said, particularly for the department's preferred antibiotic -- ciprofloxacin.

For example, treating 5,000 personnel with ciprofloxacin for 40 days to 60 days would cost DOD about $500,000, the official said. By comparison, doxycycline -- considered an "acceptable" but less-effective alternative -- runs about 5 percent of the cost of ciprofloxacin.

Despite the cost, the treatment is essential and DOD policy directs that military health professionals use ciprofloxacin for the post-exposure treatment of anthrax whenever possible. However, this use of ciprofloxacin is somewhat problematic, according

to this official, because the drug is not labeled for the treatment of anthrax, while doxycycline is. Although an individual physician treating an individual patient may legally elect to use a drug off-label for a particular treatment, whether a department or entity treating a population of people can make the same choice is unclear, the official explained.

"If you've got an A-plus drug that's expensive and not on-label, but more effective, and a B-plus drug that is more affordable and on-label, but less effective, what do you do?" the official asked. "Americans want the best."

The official did not explain what basis DOD had for thinking that ciprofloxacin is a better drug than doxcycline, and a DOD health operations policy spokeswoman said she could not respond to requests for that answer by press time. Due to the "sensitivities" and complexities of the issue, she said the question is "not easy to put into a sentence or two."

According to U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) research conducted between September 1990 and February 1991, a test group of 10 unvaccinated rhesus monkeys treated with doxycycline within a day of exposure for 30 days fared better than another set treated with ciprofloxacin, with survival rates of 90 percent and 89 percent, respectively. All subjects were exposed to a fatal dose of anthrax in aerosol form. A group of monkeys that received a combination of doxycycline and vaccine had a 100 percent survival rate (ITP, March 2, p3).

Meanwhile, unvaccinated human patients showing signs of disease are treated with intravenous penicillin under DOD policy.Specifically, 24 million units per day for 10 days, the official said.