Medicines And Pharmacology Flashcards
What route of administration allows for higher bioavailability compared to oral drugs? Why?
Sublingual and rectal drugs. Do not pass through the liver first (no first-pass metabolism)
What determines skin absorption of a medication?
Based on the lipid solubility through the epidermis
What kind of drugs are absorbed by the CSF?
Non-ionized, lipid soluble drugs
What is responsible for mostly binding of drugs in the body?
Albumin
Penicillins and warfarin area 90% bound
Why should we avoid sulfonamides in newborns?
Because it will displace unconjugated bilirubin from albumin in newborns which can cause kernicterus
Where in the body are tetracyclines and heavy metals stored?
In bone
Describe zero order kinetics?
Constant amount of drug is eliminated regardless of dose
Describe 1st order kinetics?
Drug eliminated proportional to dose
How many half lives does it take to reach steady state?
5
What is the definition of volume of distribution?
Amount of drug in the body divided by amount of drug ini the plasma or blood
What does it mean to have a high volume of distribution
The drug has a higher concentration in the extra-vascular compartment (fat tissue) compared with intramuscular concentration
What is the definition of the bioavailability of a drug?
Fraction of unchanged drug reaching the systemic circulation
What is the bioavailability for IV drugs?
100%
Less for other routes
What is the ED50?
The drug level at which desired effect occurs in 50% of patients
What is the LD50?
Drug level at which death occurs in 50% of patients
