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Nuclear Exposure The Role of Potassium Iodide. Evelyn R. Hermes-DeSantis, Pharm.D., BCPS Ernest Mario School of Pharmacy Rutgers the State University of New Jersey. Objectives. Discuss the risks associated with a nuclear exposure. Select the appropriate management for a nuclear exposure.
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Nuclear Exposure The Role of Potassium Iodide Evelyn R. Hermes-DeSantis, Pharm.D., BCPS Ernest Mario School of Pharmacy Rutgers the State University of New Jersey
Objectives • Discuss the risks associated with a nuclear exposure. • Select the appropriate management for a nuclear exposure. • Recommend the dosing schedule of potassium iodide.
Nuclear Accidents • Tokaimura, Japan September 30, 1999 • Chornobyl (Chernobyl) Nuclear Disaster Unit number 4 in Ukraine on Saturday, April 26th 1986 at 1:23 a.m. • Three Mile Island Power Station, Pennsylvania, US on March 28, 1979
Cancer risk • Three Mile Island • Very little radioactivity released into the air • Leukemia rates increased
Chernobyl Data Belarus and Ukraine • Increase incidence of thyroid cancer among children and adolescents • Attributed to ingested or inhaled radioiodines • Majority of cases received less than 30 cGy to the thyroid
Chernobyl Data- Poland • KI distributed to 10.5 million children and 7 million adults • 0.37% of newborns demonstrated transient increases in TSH and decreases in free T4 • Adverse effects - up to 2% GI, 1% rash
Thyroid cancer • Risk of thyroid cancer – inversely related to age • Children exposed to > 5 cGy
Radiation exposure • Immediate effects • Flash and flame burns • Blindness – temporary or permanent • Long-term effects • Thyroid cancer
Effects of radiation • Time • Absorbed dose – directly proportional • Distance • Absorbed dose – decreases rapidly • Triple the distance – dose is one-ninth • Shielding • Lead • Indoors
Half-lives • Short-lived • Iodines • Long-lived • Cesium • Strontium • Cobalt • Decay rate affects management
Clinical effects • Rapidly dividing cells most vulnerable • Dose < 1.0 Gy, damage not severe • Cells survive but susceptible to subsequent malignant transfusion • Leukemia – 2 years • Radiation induced solid tumors – 5-10+ years
Clinical effects – local exposure • 3-4 Gy Epilation in 2-3 weeks • 10-15 Gy Erythema • 20 Gy Moist desquamation, ulceration • 25 Gy Ulceration with slow healing • 30-50 Gy Blistering, necrosis at 3 weeks • 100 Gy Blistering, necrosis at 1-2 weeks
Effects – whole body • < 1 Gy No symptoms • 1 Gy Nausea and vomiting (10%) within 48 hours • > 2 Gy Nausea and vomiting (50%) within 48 hours • 4 Gy Nausea and vomiting (90%) within 48 hours; 50% mortality without medical attention • 6 Gy 100% mortality within 30 days • 10-30 Gy • Rapid onset of nausea, vomiting, and diarrhea • Latent period x 1 week • Recurrent GI symptoms, sepsis, electrolyte imbalance,death
Thyroid exposure • Largely due to consumption of contaminated fresh cow’s milk • Consumption of contaminated vegetables • Inhalation
Management exposure • Recognition • Based on history and clinical findings • Local injury worse than systemic • Prevention • Treatment • Symptoms, i.e. burns • Supportive care
Prevention • Time • Food control measures • Stored for weeks to months – no risk • Evacuation • Shelter
Therapy for Internal Contamination • Tritium • Force fluids • Cesium 134 or Cesium 137 • Reduce GI absorption, Prussian blue • Strontium 89 or strontium 90 • Reduce absorption (Al PO4), blockage (strontium lactate), displacement (oral phosphate), mobilization (ammonium chloride, parathyroid extract)
Therapy for Internal Contamination • Plutonium or other transuranic elements • Chelation with zinc • Unknown • Reduction of absorption (emetics, lavage, charcoal, laxatives) • Iodine 125 or Iodine 131 • Blockage (KI), mobilization (antithyroid drugs)
Potassium Iodide • Short-term administration – safe • Adverse effects: • Gastrointestinal disturbances • Allergic reactions • Minor rashes
Potassium Iodide • Avoid in patients with: • Known iodine sensitivity • Dermatitis herpetiformis • Hypocomplementemic vasculitis • Not necessary to avoid in patients with seafood allergy
Potassium Iodide – dosing • 130 mg KI • Adults over 40 years, Predicted exposure > 500 cGy • Adults 18-40 years, Predicted exposure > 10 cGy • Pregnant/lactating, Predicted exposure > 5 cGy
Potassium Iodide – dosing • Children 3-18 years, Predicted exposure > 5 cGy • 65 mg KI • Children 1 mo-3 years, Predicted exposure > 5 cGy • 32 mg KI • Birth-1 month, Predicted exposure > 5 cGy • 16 mg KI
Potassium Iodide • Effect last 24 hours • Administer immediately coincident with cloud, up to 3-4 hours after exposure • Daily dosing until risk of significant exposure by inhalation or ingestion passes • Do NOT repeat dosing in: • Pregnant and lactating women
Potassium Iodide • Slaladenitis • Gastrointestinal disturbances • Allergic reactions • Minor rashes
Psychosocial effects • Acute stress reaction • Post Traumatic Stress Disorder • Long term risks • Prevention • Goal – maintain or restore trust
Summary • Potassium Iodide • Safe • Effective for preventing thyroid cancer • Evacuation still main protection