Terrorism: Medical Countermeasures, Part 2

by Food and Drug Administration (FDA)

(Page 4 of 4)

In December 2002, President Bush announced a voluntary national plan to contain a smallpox outbreak through vaccinating smallpox response teams across the country. These teams are made up mostly of health care workers. Part of the plan involved developing a national stockpile of the vaccine. The FDA's work with manufacturers and the CDC has boosted the stockpile of investigational smallpox vaccine by hundreds of millions of doses. In addition, under CDC-sponsored INDs, the FDA has approved the use of various investigational smallpox vaccines. The FDA has also approved INDs for Vaccinia Immune Globulin (VIG), which is used to treat some rare but life-threatening complications of the smallpox vaccine. The FDA's research laboratories have developed two new methods to test and monitor the strength of VIG preparations.

In the spring of 2003, the CDC and DoD reported several types of cardiac problems among some people who had recently received the smallpox vaccine. The FDA is working with other agencies on the ongoing evaluation of these events. Although it's unknown if smallpox vaccine causes atherosclerotic cardiovascular disease, the Advisory Committee on Immunization Practices recommends that people with underlying heart disease or three or more known cardiac risk factors (hypertension, diabetes, and smoking, for example) not be vaccinated. Also, a link between the smallpox vaccine and inflammatory heart disease appears to be likely.

The FDA made appropriate changes to the Dryvax package insert to reflect these findings. Several smallpox vaccines that are related to the same vaccine strain used in Dryvax but grown in cell culture are being developed. FDA scientists are pursuing studies that may support development of safer smallpox vaccines.

Plague: Plague is caused by the bacterium Yersinia pestis. Bubonic plague is the most common type of naturally occurring plague. It is transmitted through the bite of an infected flea or exposure through a cut. Symptoms of bubonic plague include swollen, tender lymph nodes, headache, fever, and chills. If untreated, bubonic plague may result in death.

In pneumonic plague, the lungs are infected with the plague bacterium. People with pneumonic plague can transmit plague to other people, whereas bubonic plague cannot be spread from person to person. Antibiotics approved by the FDA to treat plague are streptomycin, doxycycline, and other drugs in the tetracycline class.

The FDA has requested grant applications for clinical trials for plague treatments, and in conjunction with the CDC, the FDA is funding research on evaluating rapid diagnostic test kits for plague. The FDA, along with the NIH and DoD, has funded studies investigating the safety and effectiveness of gentamicin and other antibiotics for plague. There is no plague vaccine available in the United States. The originally licensed whole-cell plague vaccine is no longer being manufactured and there is no vaccine inventory remaining. Given the potential threat, the FDA is accepting applications for newly developed plague vaccines that could be licensed.

Nerve Agents: These chemical agents interfere with nerve function, causing paralysis, suffocation, and seizures. The FDA worked with the U.S. Army to approve pyridostigmine bromide for combat use to protect people in the military from soman, a nerve gas that can kill in 15 minutes. Evidence of pyridostigmine bromide's effectiveness was obtained primarily from studies in monkeys and guinea pigs. It was the first drug approved under the animal efficacy rule.

In January 2002, the FDA also approved ATNAA (atropine/pralidoxime) autoinjector to treat nerve gas intoxication. And in June 2003, the agency approved new dosage forms of AtroPen (atropine) autoinjectors for use in children and adolescents exposed to nerve agents.

In March 2003, the FDA cleared Reactive Skin Decontamination Lotion for use by the military to remove or neutralize chemical warfare agents and T-2 fungal toxin from the skin.

Radioactive Contamination: Radioactive material could be introduced into the food or water supply or with explosives that spread radioactive materials.

In 2001, the FDA collaborated with the NIH to issue a final guidance applying to children and adults on the use of potassium iodide (KI) in radiation emergencies. When given in the recommended dose, KI reduces the risk of thyroid cancer in people at risk for inhaling or ingesting radioiodines. KI floods the thyroid with non-radioactive iodine and prevents the thyroid's uptake of radioactive molecules.

In September 2002, the FDA approved ThyroSafe Tablets (potassium iodide) as a thyroid-blocking agent for use in radiation emergencies. This drug underwent fast review, and the dosage form can be used in children because it's half the strength of formulations that were previously approved.

Normally, a drug or device company collects data on a new product and submits it to the agency. But in two instances, the FDA found the data on its own, and then called for manufacturers to submit applications. The first example is Prussian blue, a substance that has been used as a pigment for artists since 1704. The substance can treat people exposed to radioactive cesium or radioactive and non-radioactive thallium. Radioactive cesium could be used in a "dirty bomb" or other terror device. Prussian blue traps thallium or cesium in the intestine so that they can be passed out of the body in the stool rather than reabsorbed into the body. This reduces the amount of radiation in the body. In March 2003, the FDA received its first marketing application for Prussian blue in response to the agency's call for applications. On Oct. 2, 2003, this application was approved, giving the nation the first drug that can be used as a medical countermeasure to the threat of radioactive cesium.

The FDA also determined conditions under which pentetate calcium trisodium (Ca-DTPA) and pentetate zinc sodium (Zn-DTPA) are safe and effective for treating certain kinds of radiation exposure. The agency then encouraged submission of new drug applications for these products. Ca-DTPA and Zn-DTPA are usually given intravenously, and have been used as investigational drugs for 40 years.

The FDA determined the drugs can be safe and effective for treating internal contamination with plutonium, americium, or curium, substances that can be found in the fallout from the detonation of nuclear weapons and waste from nuclear power plants. Ca-DTPA and Zn-DTPA work by increasing the rate of elimination of these substances from the body.

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.