Be prepared: Anthrax outbreaks may not remain isolated acts, experts say

ASHP recommends following CDC guidelines

You may think you will never see an anthrax case at your hospital. Two experts from the National Institute of Allergy and Infectious Diseases at the National Institutes of Health in Bethesda, MD, say you might be wrong.

"There is no reason to believe this will be an isolated act of bioterrorism. In fact, it is likely that additional attacks involving [Bacillus] anthracis and perhaps other pathogens will occur," say H. Clifford Lane, MD, and Anthony S. Fauci, MD, in the Nov. 28 issue of the Journal of the American Medical Association.

Each attack will present the health care community with a new set of challenges and a need for rapid dissemination of reliable, up-to-date information, say Lane and Fauci. To successfully deal with these challenges, law enforcement authorities, public health officials, and front-line health care providers must promptly share information, they note. "The alertness, open-mindedness, and sound clinical judgment of physicians and other health care professionals will be critical to the successful public health response to current and future threats."

Treatment guidelines

Since the first announcement on Oct. 4 of the inhalation anthrax case in Florida, information on how to handle the threat has been updated constantly. The Centers for Disease Control and Prevention (CDC) in Atlanta has been in the forefront of providing information. In its Oct. 26 issue of Morbidity and Mortality Weekly Report, the CDC released comprehensive guidelines for the treatment of inhalation, gastrointestinal, and cutaneous (skin) anthrax. The recommendations are based on clinical reports and in vitro data.

For example, a 60-day regimen of antibiotics beginning with intravenous ciprofloxacin (Cipro) or doxycycline is recommended to treat inhalation anthrax, along with one or two additional antimicrobials. Treatment can be switched to oral antimicrobial therapy when clinically appropriate. The recommendations are the same for pregnant women and immunocompromised people.

The American Society of Health-System Pharmacists (ASHP) advises pharmacists to follow the CDC recommendations, but to be alert for potential changes in the recommendations. "Due to limited experience with anthrax, especially when exposure is through these covert actions, it is difficult to establish firm recommendations," says David R. Witmer, PharmD, director of ASHP’s professional practice and scientific affairs.

American Hospital Formulary Service, ASHP’s drug information resource, is fast-tracking new monographs on drugs used in the treatment of several infectious agents. These monographs will be available at the society’s Midyear Clinical Meeting Dec. 2-6 in New Orleans.

The Food and Drug Administration (FDA) in Rockville, MD, also issued a Federal Register notice on Oct. 30 to clarify that doxycycline and penicillin G procaine currently are approved for use in treating all forms of anthrax infections — cutaneous, inhalation, and gastrointestinal.

The notice includes dosing and other information on the use of these antibiotics to treat anthrax. The currently recommended dosage regimen of doxycycline for severe disease is 100 mg every 12 hours for adults and 1 mg/lb (2.2 mg/kg) every 12 hours for children less than 100 pounds. Although doxycycline and other members of the tetracycline class of antibiotics generally are not recommended for patients younger than age 8 because of negative effects on teeth and bone development, the FDA believes the benefits of doxycycline for the treatment of inhalational anthrax outweigh these risks.

The full-text of the Federal Register notice can be found on-line at www.fda.gov/OHRMS/DOCKETS/98fr/110201b.htm.

Addressing the shortage issue

In the initial stages of the anthrax crisis, health care professionals worried that a run on ciprofloxacin (Cipro), which is manufactured by Bayer Corp., would result in a shortage. On Oct. 24, however, Health and Human Services (HHS) Secretary Tommy G. Thompson and Helge H. Wehmeier, president and CEO of Bayer, announced an agreement for a significant federal purchase of the antibiotic at a substantially lowered price. The ciprofloxacin is expected to be available by year-end.

Under the terms of the agreement (valued at $95 million), HHS will pay 95 cents per tablet for a total initial order of 100 million tablets. This compares with a previously discounted price of $1.77 per tablet paid by the federal government. Bayer said that as part of the agreement, it will rotate the government’s inventory to ensure a fresh supply. This inventory rotation adds an additional value of 30% for the government, which is included in the agreement. A $1.6 billion emergency proposal made by President George W. Bush on Oct. 17 includes funds for the purchase.

HHS also is making substantial new purchases of other antibiotics that are effective against anthrax, especially doxycycline.

The purchases will fulfill Thompson’s proposal to quickly increase the nation’s emergency reserve of antibiotics. Resources to be on hand by January would treat up to 12 million people immediately for anthrax exposure. Treatment would be with a mixture of effective antibiotic products, with ciprofloxacin representing about 10% of the antibiotics on reserve. In October, 18.6 million ciprofloxacin doses were available in the nation’s emergency reserve, which would enable immediate treatment of about 2 million people when combined with other antibiotics.

Meanwhile, other drug companies are offering their products to the government. Bioglan Pharma has announced that its doxycycline (ADOXA) tablets are available for treating anthrax. Abbott Laboratories says it would provide supplies of its antibiotics, including clarithromycin (Biaxin), free of charge if requested and approved by the U.S. government. Bristol-Myers Squibb has offered a similar plan for its antibiotic gatifloxacin (Tequin), and GlaxoSmithKline for its amoxicillin (Amoxil) and amoxicillin/clavulanate potassium (Augmentin) drugs. GlaxoSmithKline also says it has submitted a proposal to the government to begin manufacturing smallpox vaccine.

Pfizer has announced increased production of its doxycycline (Vibramycin) in anticipation of possible future demand. Pfizer says it is discussing with public health authorities the possible use of the company’s other human antibiotics, including azithromycin (Zithromax), trovafloxacin (Trovan), and company-produced penicillins, too.