Study Set Content:
The more rapidly a chemical is eliminated from an organism, the ()will be its concentration and hence its toxicity in target tissues. If a chemical is distributed to and stored in at, its elimination is likely to be slow because very low plasma levels preclude rapid renal clearance or other clearances.
lower
GIT – accidental ingestion is the most common cause of unintentional exposure to a toxicant (especially for children) and intentional overdoses most frequently occur via the
oral route
Depends on physical properties (lipid solubility and dissolution).
GIT
usually gases, vapors or volatile or volatilizable liquids, and aerosols
Lungs
The nose acts as a () or water-soluble gases and highly reactive gases. Although this may serve to reduce systemic exposure or to protect the lungs, it also increases the risk that the nose could be adversely affected.
“scrubber”
Rate of absorption depends on the solubility ratio at
equilibrium
Skin – the() is the outermost layer of the skin and is unique in that it represents the single most important barrier to preventing fluid loss from the body while also serving as the major barrier to prevent absorption of xenobiotics into the body.
stratum corneum
Skin
o Integrity of the stratum corneum o Hydration state of the stratum corneum o Ambient temperature o Solvent as carriers o Molecular size
introduces the toxicant directly into the bloodstream, eliminating the process of absorption.
Intravenous
Special routes of administration
Intravenous
o Intraperitoneal
o Subcutaneous
o Intramuscular
Volume in which the amount of drug would need to be uniformly dissolved in order to produce the observed blood concentration.
Volume in Distribution
as Storage Depot
Plasma proteins
toxicity manifested by unbound fraction & competition and displacement of already () compounds
bound
as Storage Depots
Liver and kidney
highly lipophilic, less severe in an obese person than in a lean individual.
Fat as Storage Depot
The possibility of a sudden () in the concentration of a chemical in the blood and thus in the target organ of toxicity when rapid mobilization of fat occurs must be considered.
increase
Storage of Toxicants in Tissues
Bone
Only the () toxicant equilibrates rapidly with the brain.
free unbound
are important determinants of the rate of entry of a compound into the CNS.
Lipid solubility and degree of ionization
Associated with the concentrations of a toxic in the plasma of the mother and fetus.
Passage Across the Placenta
