General Toxicology

Question 1

Most common route of exposure?

Answer 1

Oral Route

Dermal - Insecticides, Inhalant- Toxic Gases

Question 2

Lethal Synthesis

Answer 2

The metabolite is more than the parent compound

Question 3

Drug Absorption

Answer 3

The transfer of the drug from the site of administration to the circulation

Question 4

Molecular Size

Answer 4

The smaller the molecular size, the faster its penetration through the pores.

Question 5

Lipid Solubility

Answer 5

The greater the lipid solubility, the greater the absorption.

Question 6

Degree of Ionization

Answer 6

The higher the ratio between N/I, the greater the absorption.

Question 7

Route of Administration

Answer 7

Fastest to Slowest

Sublingual/Inhalation, Intramuscular, SQ, Oral

Question 8

Sympathetic Stimulation on Blood Flow

Answer 8

Increases to the skeletal muscles

Decreases to the GIT and SQ sites and skin

Question 9

T/F: The upper part of the SI is the main site of absorption.

Answer 9

True- has an extensive surface area and rich blood supply

Question 10

Drug Disposition

Answer 10

The study of the movement of drugs in the body across biological membranes from the time of absorption until elimination.

Question 11

Biological Cell Membranes

Answer 11

• Lipid Bilayer
• Membrane Proteins and Carbohydrates
• Aqueous Pores or Junctions between cells

Question 12

2 types of Passive Diffusion:

Answer 12

Transmembrane or Paracellular movement

Simple Diffusion

Question 13

T/F: Transmembrane movement of water is through intercellular aqueous pores.

Answer 13

False. That is Paracellular Movement.

Transmembrane Movement: by passive diffusion through aqueous protein channels or by flow resulting from osmotic or hydrostatic difference across the membrane.

Question 14

T/F: Most drugs are strong electrolytes.

Answer 14

False.

Most are WEAK electrolytes

Question 15

Which way does a drug move in Passive Diffusion?

Answer 15

From High to Low Concentration.

Question 16

T/F: With Active Transport, drugs move from Low to High concentrations.

Answer 16

True. This is a carrier-mediated transport and requires energy.
Primary- directly from ATP
Secondary- stored energy leftover from Primary Active Transport.

Question 17

Pinocytosis

Answer 17

When the cell engulfs the drug molecules dissolved in water.

Ex. Sequestration of aminoglycoside antibiotics by renal tubular cells.

Question 18

Drug Distribution

Answer 18

The transport of drugs from the plasma to the tissues (site of action, site of storage, site of biotransformation).

Question 19

T/F: Acidic drugs bind to acid alpha1-glycoproteins and lipoproteins.

Answer 19

False. Basic Drugs bind to those.
Acidic drugs bind to Albumin.

Some other drugs bind to Globulin.

Question 20

Plasma Protein Binding

Answer 20

• Reversible
• Prolongs the half-life of the drug
• Bound form is Inactive
• Drugs can compete on the binding sites

Question 21

Highly Perfused Tissues

Answer 21

Brain, Liver, Kidney, Endocrine Glands

Question 22

Moderately Perfused Tissues

Answer 22

Muscle, Skin

Question 23

Poorly Perfused Tissues

Answer 23

Bone, Fat

Question 24

5 Tissue Barriers

Answer 24

Brain, Eye, Testicles, Placenta, Mammary Gland

Question 25

Blood-Brain Barrier

BBB

Answer 25

• Tight capillary endothelial junctions
• Glial Cells
• Flow of CSF into venous drainage
• Active transport mechanisms for extrusion of organic acids or bases

Question 26

Match the Drug to the Tissue:
Drug- Tetracycline, Aminoglycosides, Iodine

Tissue- Kidney Tissue, Thyroid Gland, Skeletal Tissue

Answer 26

Tetracycline- to calcium in Skeletal Tissue

Aminoglycosides- Kidney Tissue

Iodine- trapped by the Thyroid Gland

Question 27

Redistribution of Drugs

Answer 27

The movement of the drug from the tissues to the blood.

Ex. Thiopental vs. Phenobarbital