|
-Treatment-
Preparedness
As previously mentioned, an effective response to bioterrorism will require prepared, well-trained local responders who can interact with state and federal agencies. Training for responders should cover the characteristics of biological and nonbiological agents that can be used in case of destruction.
Pharmacists should be trained in their duties as responders, and they should be protected in the event of an attack so they can perform those duties. Security of the pharmacy may be a top concern, because break-ins to obtain medications may occur.
Although the threat of terrorist attacks has grown in recent years, natural disasters such as floods, hurricanes, and tornadoes are a recurring cause of mass destruction. For these situations, too, pharmacists should be involved in local disaster planning. Even small communities must be prepared to handle a mass casualty incident until state and federal assistance arrives. In such circumstances, healthcare providers must manage many patients who require urgent care, and pharmacists are likely to be pressed into action to deliver the medications needed to save lives; relieve pain; and limit potential damage from exposure to caustic, infectious, or other harmful agents. Pharmacists may be involved in treating not only patients suffering from exposure to nerve gas, biological weapons, or trauma, but also victims of a bombing.
Pharmacies' maintenance of just-in-time inventory works against an adequate response to disasters and terrorism. Competition for limited resources could challenge the ability to maintain civic order. Pharmacists involved in an emergency situation may find that providing information is relatively simple but providing pharmaceuticals is more difficult because pharmacies routinely stock commercially available products in limited quantities only. Many pharmacists can compound some preparations to help fill the need until commercial stocks are replenished. Compounding pharmacists can provide various dosage forms to all types of patients.
Causative Agents
As discussed in previous issues of this newsletter, terrorists may use any of the following:
- chemical agents
- choking agents
- biological agents
- blood agents
- nerve agents
- lung agents
- blister agents
- nuclear agents
Let's look at the treatment that may be associated with these agents.
Chemical Agents Treatment
Blood agents produce their effects by interfering with oxygen use at the cellular level. Certain types of cyanide are referred to as blood agents. Nitrite is the common ingredient used to displace cyanide from the oxygen that carries hemoglobin after contact with a blood agent has occurred. Other pharmaceuticals that serve as adjunctive therapy for cyanide poisoning are injectable sodium bicarbonate, which can correct metabolic acidosis, and benzodiazepines (e.g., diazepam, lorazepam), which are used as anticonvulsants. Formulations that counteract the effects of blood agents include: (1) sodium nitrite 3% injection, (2) sodium thiosulfate 25% injection, (3) sodium bicarbonate 8.4% injection, (4) diazepam 5-mg/mL injection, and (5) lorazepam 2-mg sublingual tablets.
Biological Agents Treatment
Biological terrorism could involve sophisticated or unsophisticated techniques (i.e., use of dried anthrax spores or botulinum toxins or use of Salmonella or other common bacteria, respectively). Unlike chemical nerve agents, which can cause immediate death or severe injury at the site of attack, biological agents cause delayed signs and symptoms because of their incubation periods. If used against unsuspecting, nonimmune civilian populations, biological weapons could enable terrorists to cause a large number of casualties and create international panic. In the event of an attack, frontline clinicians and primary-care practitioners will need to identify and manage exposed patients. Pharmacists will need to be knowledgeable about diseases caused by biological agents and about patient management, vaccines, and potential chemotherapeutic agents, so that they can educate the public and other healthcare practitioners.
Many oral and injectable medications, in extraordinarily large amounts, may be needed to treat an outbreak of illness caused by a biological weapon. Pharmaceutical needs will depend on the duration of illness, the virulence of an outbreak of disease, and the number of patients affected. Uncommonly used vaccines and antitoxins should be prepositioned with the assistance of federal government storage and distribution programs.
Nerve Agents Treatment
Nerve agents are organophosphorus cholinesterase inhibitors. They inhibit the enzyme acetylcholinesterase. Chemotherapeutic intervention consists of the use of three antidotal agents: atropine sulfate, which blocks muscarinic receptor sites; pralidoxime chloride, which regenerates cholinesterase activity; and diazepam or lorazepam, both of which are used as anticonvulsants. Topical ophthalmic homatropine or atropine can be used to relieve dim vision, pain, and possible nausea. Formulations to counteract the effects of nerve agents include (1) pralidoxime chloride injection (1-g vial), (2) atropine sulfate 1-mg/mL injection, and (3) diazepam 5-mg/mL injection.
Lung Agent Treatment
No specific antidotes exist for these lung and eye irritants, but supportive care may include the use of bronchodilators such as nebulized albuterol sulfate or sodium bicarbonate. Methylprednisolone acetate injection also has been used as supportive therapy to counteract the effects of these agents. Formulations that counteract the effects of pulmonary agents include (1) albuterol sulfate 0.5% inhalation solution, (2) sodium bicarbonate 3.75% inhalation solution, and (3) methylprednisolone acetate 40-mg/mL injection.
Blister Agents Treatment
Only one blister agent, lewisite, has an antidotal compound (dimercaprol), which acts as a chelating agent for arsenicals and other heavy metals. Dimercaprol skin and eye ointment applied to victims after decontamination may reduce the severity of lesions.
Dimercaptosuccinic acid (DMSA) has been used successfully in animals for the treatment of lewisite exposure and lead ingestion. Available in 100-mg capsules, dimercaptosuccinic acid can be administered orally to treat multiple exposures to blister agents. Formulations that counteract the effects of blister agents include (1) silver sulfadiazine cream, (2) mafenide acetate cream, (3) dimercaprol injection, (4) dimercaprol ointment, and (5) dimercaptosuccinic acid 100-mg capsules.
Nuclear Agents Treatment
Dirty bombs, conventional explosives used to spread hazardous radioactive material, might be involved in a terrorist attack. Radioactive materials can emit three types of harmful radiation: α (alpha), β (beta), and γ (gamma). Inhalation or ingestion of α or β particles poses the greatest hazard. The most harmful type overall, γ rays, can penetrate most sheltering material in a wide area. Exposure to a harmful radiological agent may require treatment with a chelator or a radionuclide blocker. Some general radionuclide chelating agents are penicillamine (Cuprimine), edetate calcium disodium (Calcium Disodium Versenate), dimercaprol (British anti-Lewisite, or BAL), succimer (Chemet), and deferoxamine (Desferal). (Colony-stimulating factors may be considered in patients experiencing significant bone-marrow suppression.) Information about this specialized class of drugs can be obtained 24 hours a day from the Radiation Emergency Assistance Center/Training Site (http://orise.orau.gov/reacts/), telephone 865-576-3131, or 865-576-1005 for emergencies.
A variation of radionuclide chelation to entrap and remove the radioactive agent is the use of radionuclide-blocking agents. These agents saturate tissues with a nonradioactive element that reduces the uptake of radioactive iodine. The most commonly known radionuclide-blocking agents are potassium iodide tablets and Lugol's solution, both of which reduce the uptake of radioactive iodine by thyroid tissue.
Pharmacists' Involvement During an Emergency
Pharmacists' involvement in disaster planning is the first step in preparing for a terrorist attack. A formulary should be developed to include primary and secondary treatments for the effects of chemical, biological, and nuclear weapons. Variables in the dosing of antibiotics, antitoxins, vaccines, and prophylactic treatments for adolescent and pediatric patients should not be overlooked. The use of chemotherapeutics (and their respective teratogenic effects) in pregnant patients should be noted in each treatment protocol. Because a chemical, biological, or nuclear attack will create drug shortages, pharmacists should have preplanned procedures for rationing and agreements for support from a network of pharmacies.
Pharmacists can also provide valuable information when the agent used in an attack may not be clear, such as in an unusual outbreak of infections. Because they often see hundreds of patients daily, pharmacists can help detect unusual occurrences that might be related to bioterrorism. For example, pharmacists might observe cases of a disease that is not endemic, unusual patterns of antibiotic resistance, atypical clinical presentations, case distribution in a certain geographic region, unusually high numbers of cases, and morbidity and mortality rates that deviate from the baseline. After a terrorist incident occurs, pharmacists working with limited assets will be asked to provide medications in a very short time. In preparation for this situation, pharmacists should maintain current, accurate information on product procurement and manufacturing options. Self-reliant and adaptable, compounding pharmacists can provide drug treatment alternatives to lessen the damage from an attack. Formulations and procedures for extemporaneous compounding must be created, reviewed, and tested before an emergency occurs. Preestablished reference publications, bulk materials, source information, and pharmaceutical items (antibiotics, antidotes, antitoxins, other supportive-care agents) will facilitate hands-on training in the treatment of victims of biological, chemical, or nuclear attacks. In addition to providing pharmaceuticals, pharmacists can disseminate supplies such as gloves, gowns, masks, and respirators; provide information about dosages and vaccination schedules; and counsel patients.
More next week.
Loyd V. Allen, Jr., PhD, RPh
Editor-in-Chief
International Journal of Pharmaceutical Compounding
Remington: The Science and Practice of Pharmacy Twenty-second edition
|
