Toxicology Exam 3

  1. Heavy metal poisoning
    toxic accumulation of heavy metals in the soft tissues of the body
  2. Methods for heavy metals to enter the body
    • food
    • water
    • air
    • absorption through the skin
  3. Heavy metals compete with and displace ___ in the body
    • essential minerals
    • zinc
    • copper
    • magnesium
    • calcium
  4. Treatment of heavy metal poisoning
    • minimize long-term damage to the patient's nervous system and digestive tract
    • pt should be takent to an emergency room
    • treatment for most is chelation therapy
  5. Chelating agents specific to the metal involved in poisoning can be given
    • orally
    • IM
    • IV
  6. Complexation and chelation therapies
    • BAL
    • DMPS
    • DMSA
    • CaNa2
    • Deferoximine
    • Penicillamine and N-Acetylcysteine
    • Hemodialysis with chelation
  7. A provoking agent in testing for the presence of heavy metals and as a treating agent for heavy metal toxicity
    DMPS
  8. Blood levels of heavy metals a few hours after exposure
    • blood levels low
    • tissue levels high
    • must use provoking agent
  9. Major toxic metals with multiple effects
    • arsenic
    • beryllium
    • cadmium
    • lead
    • mercury
    • nickel
  10. Arsenic poising is shown by
    lesions on hands
  11. Beryllium poisoning results in
    pancreatic cancer
  12. No known biological function in animals and is highly toxic
    arsenic
  13. sources of arsenic
    • pesticides/herbicides/fungicides
    • ceramic/enamels
    • paints/wood preservatives
    • 6 mcg/pack of cigarettes
  14. Arsenic compounds are _____ to body systems
    directly toxic
  15. Main clinical signs of arsenic poisoning
    • hemorrhagic gastroenteritis
    • fluid loss
    • n/v
    • abdominal pain
  16. Carcinogenicity of arsenic
    • proven carcinogen of lung and skin
    • suspected bladder or kidney carcinogen
  17. Treatment of arsenic poisoning
    • dimercaprol
    • penicillamine (less effective)
    • DMPS
    • DMPS + Dimercaprol (very effective)
  18. Aldrich-Mees lines
    white lines in the nail beds resulting from Arsenic exposure
  19. Chronic exposure to cadmium
    accumulation in the body, particularly in the kidneys and liver
  20. Cadmium is found in
    • alloys/batteries
    • pigments
    • metal coatings
    • occupational exposure from welding and smelting lead, zinc and copper
    • cigarette and vehicle fumes
  21. Acute intake of cadmium causes
    • testicular damage
    • severe gastrointestinal irritation (N/V)
    • abdominal cramps (diarrhea)
  22. Lethal dose of cadmium ingestion
    350-8900 mg
  23. Prolonged cadmium exposure results in
    • disorders of calcium metabolism causing osteomalacia
    • lung and prostate cancer
  24. t 1/2 of cadmium
    • 15-30 years
    • body burden increases with age
  25. Treatment for cadmium exposure
    • no effective treatment
    • supportive therapy for symptoms
    • chelating agents?
  26. Lead exposure results in
    • accumulation in the body
    • intelligence loss and behavioral difficulties
  27. Sources of lead
    • tetraethyl lead in petrol and plumbing
    • lead in paint, batteries, insecticides and cigarette smoke
  28. Lead absorption
    • lead or inorganic lead absorbed by ingestion or inhalation
    • organic lead (tetraethyl lead) may be absorbed through skin
  29. Gastrointestinal absorption of lead
    • varies with age
    • children absorb around 50%
    • adults absorb 10-20%
  30. Lead t1/2
    • blood = 25 days
    • tissue = 40 days
  31. Lead has an affinity in the body for
    • cell membranes & mitochondria
    • interferes with oxidative phosphorylation
  32. symptoms of lead toxicity
    • thirst and metalic taste
    • n/v/d
    • colic
    • muscle pain/fatigue
    • convulsion
    • loss of consciousness
  33. Death from lead toxicity may result from
    cerebral edema or renal failure
  34. Treatment of lead poisoning
    • DMSA is more effective than penicillamine
    • CaNa2 EDTA IV for more acutely ill patients
  35. Mercury produces illnesses such as
    • multiple sclerosis
    • alzheimer's disease
    • parkinson's disease
  36. Sources of mercury poisoning
    • liquid contact for electric switches
    • scientific instruments such as thermometers, barometers, direct current meters, hydrometers
  37. Mercury exerts its toxicity by bidning to
    sulphydryl groups in the body
  38. acute inhalation of mercury vapro produces symptoms similar to metal fume fever such as:
    • cough
    • dyspnea
    • tight/burning chest pain
    • pyrexia
  39. Severe cases of mercury poisoning may result in
    • respiratory distress
    • pulmonary edema
    • pneumonia
    • fibrosis
  40. Treatment for mercury poisoning
    • chelating agents >> Dimercaprol
    • DMPS is more effective than dimercaprol and should be used with penicillamine later
  41. Recovery from mercury poisoning
    • can take months or years
    • often incomplete even with chelation therapy
  42. Nickel toxicity
    • medium toxicity to humans
    • dermatitis/skin allergy reactions
    • lung and nasal carcinogen
    • adverse effects on heart, blood and kidneys
  43. Mechanism of nickel toxicity
    nickel can preleace metals in metallo-enzymes and cause disruption of metabolic pathways
  44. Essential metals with potential for toxicity
    • cobalt
    • trivalent chromium
    • copper
    • iron
    • magnesium
    • manganese
    • selenium
    • molybdenum
    • zinc
  45. low levels of cobalt
    part of vitamin b12
  46. high levels of cobalt
    harm the lungs and heart
  47. chromium absence in the body may result in
    • heart conditions
    • disruptions of metabolism
    • diabetes
  48. Chromium VI
    • danger to human health
    • exposure in steel and textile industry
    • also in cigarettes
    • in leather products may cause allergic reactions
    • also in fertilizers
  49. Metals related to medical therapy
    • aluminum
    • bismuth
    • gallium
    • gold
    • lithium
    • platinum
    • barium
    • vanadium
    • uranium
  50. aluminum found in ___ and can cause ___
    • antacids
    • alzheimer's disease
  51. Bismuth found in
    antacid preparations
  52. Gallium used as
    antitumor agent
  53. Gold used for
    rheumatoid arthritis
  54. lithium use
    antidepressive
  55. platinum
    anticancer agent
  56. barium
    aid to x-ray diagnostics
  57. thallium
    new poison?
  58. vanadium
    essential trace element
  59. uranium
    • military nuclear uses
    • destroys cells easily
    • found in missel casings
Author
Rx2013
ID
78827
Card Set
Toxicology Exam 3
Description
Toxic effects of metals
Updated