Week 1 pharmacokinetics Flashcards
(39 cards)
What the body does to the drug
Pharmacokinetics
What are pharmacokinetics
What the body does to the drug
body’s impact on the drug (absorption, distribution, metabolism)
What are pharmacodynamics
What the drug does to the body (actions of the drug on the body, like MOA and physiological changes)
4 processes of Pharmacokinetics
ADME (Absorption, distribution, metabolism, elimination)
These are also called biodisposition
What are Cmax and Tmax
Cmax is max amount of concentration in the body, Tmax is time to reach maximum concentration (peak effect, but depending on when the drug works. May take time (i,e, antidepressants).
Which drug ROA reaches Cmax the fastest
IV (one time IV push)
Which drug ROA reaches Cmax the slowest
Oral (PO)
Oral meds have delayed peak because need to be absorbed in GI tract
What is bioavailability
the total amount of the drug that gets absorbed into the bloodstream compared to if it was given IV (which is 100% bioavailability)
If a drug is very susceptible to first-pass metabolism, what happens to oral bioavailability
Decreases significantly/greatly reduced– it is metabolized and not as high of bioavailability, so should give a different way (rectally, sublingually, since those don’t feed into portal vein)
What is the role and significance of P-gp
Protective protein, expells drug molecules into extracellular space
Multi-drug resistant protein ( MDR-1) to prevent drugs from being metabolized (trying to protect body from invader)
Where is P-gp found
mucosa of GI tract (prevent absorption)
Liver, pancrease, kidney, cancer cells
Do P-gp inhibitors increase or decrease bioavailability
Increase bioavailability (decrease expulsion)
Do P-gp inducers increase or decrease bioavailability
Decrease (expels drug more)
If something is a P-gp inducer, what occurs to P-gp substrate absorption
Decreases p-gp substrate absorption
If something is a P-gp inhibitor, what occurs to P-gp substrate absorption
Increase P-gp substrate absorption
What is transdermal administration
A patch (i.e. nicotine patches)
Have a slow onset of action
Systemic route of administration
What are systemic routes of administration
Oral
Sublingual
IM (IM/SQ)
Rectal( PR)
Transdermal
What are targeted routes of administration
Inhalation
Topical
Opthalmic (i.e. eye drops)
Intranasal
Intrathecal (next to spine, like epidural)
What is biotransformation more commonly known as
metabolism
What ar eprodrugs
inactive parent form of drug that is activated during metabolism
What are active metabolites
When liver metabolizes drugs, creates metabolites, and these metabolites are active (still exert clinical effects). So, both drug and their metabolites have impact ( active metabolites can live longer than parent drug)
What is the overall, main goal of biotransformation
make the drug hydrophilic–> want to be more lipophilic, make it more likely to cross membranes and less likely to be excreted so that can keep making affects
Phase 1 vs phase 2 reactions
1- oxidation, hydrolysis, or reduction
2- conjugation (add polarity like acetate, sulfate, glucuronate)
Which pharmacokinetic enzyme is in half of drug interactions in biotransformation
Phase 1 enzyme CYP 3A4 or 3A5 (Cytochrome P enzyme)
Grapefruit juice inhibits this
