Midterm 1 Flashcards
drug sources
Plants: morphine & codeine from poppy plant Digitalis is from the purple foxglove Quinine is from cinchona tree bark Paclitaxel is from the yew tree
Animals:
Insulin is obtained from pigs
Growth hormone is obtained from the pituitary glands
Bacteria:
Cephalosporins and ahminoglycosides
Chemical synthesis:
Most drugs today
Fentanyl
Minerals: vitamins
drug classification
Drugs that produce birth defects, such as thalidomide, are known asteratogens
Drugs that promote the growth of cancerous tumours are calledcarcinogens.
drug safety
Should be in therapeutic range
(TI) therapeutic index LD50/ED50 lethal dose, effective dose
what are drugs
chemical substance that produces a change In body function
Has specific chemical structure which means they have chemical and biological properties
Affect the functions of cells
side effects
More of a nuisance than they are harmful
Occur at minimal doses
adverse effects
Undesired effects that may be harmful
Reduction of stage or switching to an alternative drug often will avoid or minimize these consequences
Occur at high doses
toxic effects
Drug poisoning
Life threatening
Occur at very high doses
site of action
The location within the body where the drug exerts its therapeutic effect
drug forms
Aqueous Preparations - syrups, water and sugar combined with drug remove bitter taste of many drugs
Alcoholic preparations - elixirs are drugs dissolved in various concentrations of alcohol usually 5-20%
Solid and semisolid preparations - suppositories
Powders - drugs or drug extracts that are dried and ground into fine particles
Tablets - drug powders in convenient swallowing form and disintegrate in the stomach rapidly
Troches and lozenges - flattened tablets that dissolve in the mouth
Capsules - gelatin capsules used to administer drug powders or liquids, dissolve in the stomach
Delayed release products - tablets or capsules with a special coating so that various portions of the drug that will dissolve in certain rates, they usually contain 2-3 single dose units
Enteric coated products - drugs coated with an acid resistant substance that will dissolve in less acidic portions of the intestines, these drugs should be taken on an empty stomach with water 1 hour before meals or 2 hours after meals
Suppositories - drugs mixed with a substance that will melt at body temperature administered through the urethra, vagina or rectum
Ointments - soft, oily substances containing a drug that is applied to the skin or eye
Transdermal products - bandage/patch system provides continuous source of the drug over 24 hours
routes of administration
Oral - safest Sublingual Buccal Rectal Transdermal Subcutaneous Intramuscular Intravenous - fastest Intraarterial Intreathecal Inhalation -fastest Topical Vaginal
pharmacokinetics (dame)
study of the process of drug absorption, distribution, metabolism and excretion
lipid solubility
Most drugs are water soluble and only partially lipid soluble
ionization
Many water soluble drugs are weak acids or bases that can form charged particles (ionization)
Absorption is influenced by the degree of ionization
Most drugs exist in 2 forms ionized or unionized
drug formulation
Drugs must be in a solution to be absorbed
Lipid medications are absorbed faster then solids (smaller particles get absorbed faster)
drug distribution
Plasmas protein binding, blood flow and the presence of specific tissue barriers affect how much drug reaches a certain organ
plasma protein binding
Only unbound or free drug molecules can exert a pharmacological effect
When 2 drugs compete for one plasma protein binding site one may displace the other resulting in an increased free drug concentration which can lead to adverse effects
blood flow
Liver, kidneys, and brain have largest blood supply therefore are exposed to the largest amount of a drug
Fat has low blood supply but is high in lipids so lipid soluble drugs can enter fat easily
half life
amount of time it takes for the drug blood concentration to drop by half of its original level
bioavailability
the % of the drug absorbed into the blood stream
parasympathetic nerves
CN 3, oculomotor 7,9, and 10 vagus - supply the internal organs and glands of the head, thoracic cavity and upper portion of the abdominal cavity
S2-S4 - supply the lower portion of the abdominal cavity and the pelvic cavity
parasympathetic neurotransmitter
Acetylcholine (ACH) is the neurotransmitter released at the ganglion and at the post ganglionic nerve ending
Nerves that release (ACH) are known as cholinergic nerves
Cardiac and smooth muscle membrane sites where neurotransmitters act are known as cholinergic receptors
parasympathetic system roles
rest and digest
Theparasympatheticnervous system restores the body to a calm and composed state and prevents it from overworking
sympathetic nerves
T1-L3
Thoracic nerves supply the internal organs and glands of the head and the thoracic cavity and upper abdominal cavity
Lumbar nerves supply the lower portion of the abdominal cavity and the pelvic cavity
sympathetic neurotransmitters
(ACH) is released at the ganglion but norepinephrine (NE) is released at the post ganglionic nerve endings
Nerves that release (NE) are known as adrenergic nerves
Cardiac and smooth muscle membrane sites where neurotransmitters act are known as adrenergic receptors (2 types alpha and beta)
