Pharm Week 2 Flashcards
How can drugs pass through the blood-brain barrier?
They either need to be lipid soluble or have a transport system in place
What does the rate of absorption determine ?
How soon the effects will begin
What does the amount of absorption determine ?
How intense the effects will be
What is albumin?
An abundant protein in the blood, it stays in the bloodstream due to its large size, drugs with a higher affinity to bond to albumin have a higher half-life since they have to break the bond to travel to the tissues.
What is distribution of a drug ?
How a medication gets from the bloodstream to the site of action
What is the difference between the Blood-Brain Barrier and other blood vessels?
The BBB has tight junctions that limit the ability of drugs to cross the barrier unless they are lipid soluble or have a transportation system
What is the first- pass effect?
The rapid hepatic inactivation of certain oral drugs ( to counteract this, drugs that have rapid hepatic metabolism are administered through injection)
Steps in renal drug excretion
1) Glomerular filtration- moves drugs from the blood into the tubular urine
2) Passive tubular reabsorption
3) Active tubular secretion
What are the key factors that cause one patient to respond to drugs differently than another ?
1) Age
2) Body weight
3) Pathophysiology (Kidney disease, Liver Disease, Acid-Base Imbalance, Altered Electrolytes)
What are the 3 types of drug tolerance ?
1) Pharmacodynamic- long-term administration (morphine and heroin)
2) Metabolic- tolerance resulting from accelerated drug metabolism
3) Tachyphylaxis- repeated dosing over a short time period
What is bioavailability?
The amount of active drug that reaches the systemic circulation from its site of administration
