Toxicology Flashcards
(29 cards)
Likelihood that injury will occur in any given situation
Hazard
What does lead displace in a number of important proteins?
Calcium and zinc
What is important in heme synthesis, but overdose can cause severe, life-threatening effects?
Iron
What is FDA-approved as a single-agent treatment of acute poisoning by arsenic and inorganic mercury and for the treatment of a severe lead poisoning when used in conjunction with edetate calcium disodium?
Dimercaprol
Succimer is a water-soluble analog of dimercaprol
The dose which causes death in 50% of exposed animals
LD50
Inhalation of high levels of ______ vapor over a short duration is acutely toxic to the ______, however, toxicity to the _______ system is the primary concern with chronic exposure to ______ vapor and to organic ________.
Mercury vapor Toxic to the lung Primary concern is the nervous system Mercury vapor Organic mercury
What binds iron avidly, but binds essential trace metals poorly?
Deferoxamine - this is the parenteral chelator of choice for iron poisoning because it does not compete for biologically chelated iron, as in microsomal like and mitochondrial cytochromes and hemoproteins
Range of doses that might be toxic
Spectrum of toxic dose
What is an efficient chelator of many divalent and trivalent metals in vitro?
To prevent the potentially life-threatening depletion of calcium, the drug should be administered only as the _________.
Ethylenediminetetraacetic acid
Calcium disodium salt
The dose that causes death in 50% divided by the dose that causes response in 50%
Therapeutic index- the bigger the TI the safer the drug or substance is said to be
The dose which causes a response in 50% of exposed animals
ED50
What do you use Penicillamine for?
Lead, mercury, and copper poisoning
What do you use Leucovorin calcium for?
Methotrexate poisoning
Organic mercury can cause ______ effects, inorganic mercury can cause __________ and __________ problems.
Neurological effects
Gastrointestinal and renal problems
What do you use acetylcystine for?
Acetaminophen poisoning
Expected frequency of occurrence of an undesirable effect
Risk
What can penetrate biological barriers, including the BBB, can cause significant biologic damage, and has widespread use in many human activities?
Methylmercury
What distributes evenly in tissues, but does accumulate in kidneys?
Mercury
What is used chiefly for treatment of poisoning with copper or to prevent copper accumulation as in Wilson’s disease (hepatolenticular degeneration)?
Penicillamine
What is well distributed with the ability to cross BBB and placental barrier?
Arsenic
significant problems can be associated with CNS, liver, kidney, and pancreas for arsenic, lead, and mercury
Pediatric patients will show CNS problems with what level at about 5 micrograms/dL?
lead
Toxic vs. safe, risk vs. benefit
Both are important
Risk assessment
Effects are reversible
A. Pharmacological
B. Pathological
C. Genotoxic
A- pharmacological (phototoxicity)
Pathological- causes tissue changes (hepatic necrosis because of overdose)
Genotoxic- causes long term effects in genetic components and may be transferred across generations (alkylation of DNA, radiation)
What reaction is saturable?
What reaction is not saturable?
Which reaction can you calculate a half life?
Zero order is saturable and you cannot calculate a half life
First order are not saturable
