Introduction and Routes Flashcards
What is a drug?
substance used in the treatment, prevention, or diagnosis of disease
What is also known as A.D.M.E.?
Pharmacokinetics
What does A.D.M.E. stand for?
Absorption
distribution
metabolization
elimination
How can a drug be distributed from from systemic circulation?
site of action, elimination processes, biotransformation, excretion, tissue reservoirs
Dose of drugs in solution written most commonly as
percent weight-to-volume (%w/v)
%w/w in Europe, %v/v drugs liquid at room temp
The ______ by which a drug is administered can affect 1+ aspects of the drugs action.
route
When must a drug be labeled for Over the Counter use?
When adequate directions can be written for lay use
Which drugs/products are approved for use in animal feed?
Veterinary Feed Directive (VFD)
Prohibited from any extra-label use
VFD products
How does in inclusion of epinephrine in the formulation of Lidocaine (local anesthetic) affect its action?
constricts blood vessels so the drugs stays local longer.
Parental
outside the GI tract
most absorption of drugs given p.o. occurs in the
small intestine (lower GI)
drugs given ____ usually have a wide margin of safety
P.O.
p.o. drugs must survive _____
the acidic environment of the stomach
& permeate GI mucosa and pass hepatic circulation
slower onset of action, bioavailability influenced by meals, intestinal infections or liver disease.
po drugs
in general have lower bioavailability, and requires larger doses
po
non-invasive ->may be reversible
po
Good characteristics of drugs to give orally
low molecular weight
acid resistant
lipid soluble
resistant to liver metabolism
advantages of oral drugs
easy (good owner compliance)
non-invasive (low risk sepsis)
May be Reversible
limitations of oral drug administration
delayed, variable onset of drug effect
influenced by GI motility
GI irritation
incompatible with vomiting, diarrhea, fractious animals
general complications from injections
irritation
inflammation
allergic rxn
nerve damage
SC/Subdermal injection is suitable for ______ formulations
solutions
suspensions
solid formulations
good qualities of drugs for SC injection? (will inc. its bioavailability)
small, lipophilic, uncharged
inappropriate for IV injection due to risk of forming an embolism
Drug suspensions
SC injections are more affected by _____ than IM
ambient temperature (affects blow flow)
For SC injections use a _____ gauge needle, ______ inches long
18 or 20 gauge needle
1-1.5 in. long
unsuitable for irritants (drugs in oily vehicles cause irritation)
SC
formulation in which a drug is combined with a vehicle (penetration enhancer) that promotes drug passage through intact skin
Transdermal drug delivery
advantages of TDDS
constant delivery rate
easy for owners
avoids disadvantages of other routes
not really used in animals because of the unknowns
TDDS
rich blood supply so rapid absorption
IM
better route for irritants (and oily vehicles) vs. SC
IM, IV preferred (but not for oily!)
best muscles for IM in a dog (avoid the?)
cat?
horse?
thigh, hamstring (sciatic n.)
quads, dorsal lumbar m.
base neck, semitendinosus m.
Only use ______ IV
sterile particulate free solutions
preferred route for large volume infusions
IV
allows precise control of plasma drug level (can titrate, can use drugs with very low therapeutic index)
IV
increased risk of _________ with IV injections
adverse (or intensified) effects
irreversible
IV
