Chapter 5 (using drugs therapeutically) Flashcards
local effects
largely limited to the site of administration and surrounding tissues
Organs of body have limited exposure to drug so side effects and toxicity is much less than normal
(like nasal sprays and topical creams)
Latisse
local effect drug for eye lashes that can have local side effects of skin darkening, irritation, dryness, and redness
systemic effects
occur from oral, inhaled, and parenteral absorption in which drug is ‘felt’ throughout the body
oral prednisone
systemic corticosteroid; used to treat poison ivy case but would expose organs to drug along with all skin
drugs are formulated to take advantage of particular effects
local vs systemic is decided based on the desired effect, possible side effects, and distribution
some drugs are meant to have local effects, but are absorbed to some degree systemically
leads to systemic effects even though local was desired
Bronchodilators can do this and cause nervous ‘jitters’
therapeutic effect
effect for which the drug is intended
ADRs
adverse drug reactions; side effects; unintended consequences of giving a drug; every drug has them even if they are minor
use of side effects
some drugs are reformulated to take advantage of a side effect which now becomes the therapeutic effect; eg using 1 gen antihistamines as sleep aids
adverse effects
severe side effects that may so severe that they outweigh the overall benefit and the drug will be banned; occur in all drugs at high levels
Accutane
very dangerous cystic acne drug still on the market despite being a teratogen and increasing suicidal ideation. Treats acne that can be scarring and disfiguring on faces for life and reducing self-esteem maybe leading to suicide in kids (hence why it is still on the market)
TI
therapeutic index: Toxic dose 50 / Effective dose 50
avoid drugs like Accutane and Digoxin that have low TIs
Good TI
about 20 is good because a person could take a lot of the drug without killing themselves
Low TI means there is very little room for dosing error
Idiosyncratic reactions
those which do not involve any of the known pharmacological effects of a drug and do not occur in most humans or animals (very personable)
Unpredictable, atypical, and do not involve immune mechanisms
Effect not predicted by the normal action of the drug
Not side effects
allergic reactions
antigen/antibody immune system reaction usually accompanied by release of histamine
Often pt. will develop rash, bronchoconstriction, and have a drop in BP
Not a side effect
anaphylactic reaction
worst kind of allergic reactions in which there is edema and impaired breathing; can even lead to shock and death
5 rights of medication safety
Right person Right medication Right dose Right time Right route
Accutane
isotretinoin; used to treat cystic acne
Vd
theoretical volume that would be necessary to contain the total amount of administered drug at the same concentration that is observed in the blood plasma
enterohepatic circulation of a drug is about…
recycling of certain drugs and molecules from liver to bile and then back to liver again through resorption of the bile in the small intestine that contained the drug that was secreted into the SI through bile
drug-drug interactions
may lead to ADR worse than either drug by themselves
adverse reactions occur with what drugs
all drugs have adverse reactions at high levels
volume of distribution is (formula)
distribution of drug in tissues vs plasma
dose in body/serum
protein binding of drug
the percent of drug not free to act
1/2 life
estimates duration of action of drug
local effects may be intended, but…
unintended systemic effects may occur
eg. using a bronchoconstrictor by inhalation but it leaks into systemic circulation and there are nervous jitters
topical drug admin and systemic effects
gives lowest systemic toxicity
biotransformation
same as metabolism
drug entering blood leads to
systemic effects
