Pharmacokinetics Flashcards
What does “All Dinosaurs Met Extinction” mean?
Absorption
Distribution
Metabolism
Elimination/ Excretion
What type of absorption does a lipid-soluble-drug use?
Passive Absorption
What type of absorption does a water-soluble-drug use?
Active Absorption
Bioavailability Definition?
How much of the dose you’re giving is going to reach the systemic circulation
What is the bioavailability of PO drugs?
Always less than 100%
What is the bioavailability of IV drugs?
Usually around 100%
What is bioavailability affected by?
Drug form, route, presence of food or other drugs, GI motility, liver metabolism
What is the distribution of a drug affected by?
Blood flow, tissue affinity, protein binding
If your serum albumin levels are high, what does that mean?
You have a high drug toxicity level
If your serum albumin (drug toxicity) levels are high, what could be the cause?
Poor Nutrition
Kidney or Liver Disease
What is the primary source of metabolism?
Liver
What is the half-life date?
Half the time that it takes for the drug concentration to be eliminated
What is the half-life date affected by?
Metabolism and Elimination
Onset of Action means-
Time it takes for a drug to elicit an effect.
Duration of Action means-
Time in which drug produces effect until it wears off
Peak Effect means-
Point where drug is at it’s highest concentration; therapeutic effect at maximum
Steady State means-
Plateau of medication. Amount taken equals amount lost by elimination
Drugs are primarily eliminated by what?
Kidneys and the urine
What is creatinine?
A metabolic by-product of muscle
What makes drug accumulation possible?
Poor renal function
How do you determine renal function
Creatinine Clearance (Renal Clearance)
A drug with a high renal clearance level is going to go through the body faster or slower?
Faster
A drug with a low renal clearance level is going to go through the body faster or slower?
Slower
Does a drug with a high renal clearance require more frequent or less frequent dosing?
More Frequent
Does a drug with a low renal clearance require more frequent or less frequent dosing?
Less Frequent
What is pharmacokinetics?
How the body handles the drugs we put into it
What the body does to the drug
What is pharmacodynamics?
What the drug does to the body
What are the phases of drug activity in order?
Pharmaceutic phase
Pharmacokinetic phase
Pharmacodynamic phase
What is the name of the process that occurs when the drug enters the body in one form and changes to another form so that it can get into the system and cause an action?
The pharmaceutic phase
The pharmaceutic phase can only occur whenever a drug is taken via-
PO
How does a drug with enteric coating differ from a drug with enteric coating?
A drug with enteric coating won’t dissolve in the acid of the stomach, but it will in the basic pH environment of the small intestine.
A drug with no enteric coating will dissolve in the stomach
What is Hepatic First Pass (First Pass Effect)?
Situation where a PO drug doesn’t enter the systemic circulation directly, but enters the liver where it’s metabolized to an inactive form OR transformed into a drug metabolite
What is first pass metabolism?
Metabolism of a drug before it reaches the systemic circulation
Why would the morphine dosage (PO) differ from the morphine dosage (IM/SC)?
Bioavailability.
PO Drugs always have a bioavailability less than 100%.
IV Drugs usually have a bioavailability around 100%.
Whenever something reaches the liver and is acted upon by liver enzymes, what are the two different things that can happen to it?
It can either be rendered water soluble, for excretion
OR
It can be transformed into an active metabolite
Urine pH influences excretion.
Acidic urine promotes elimination of what kind of drugs?
Weak base drugs
Urine pH influences excretion.
Alkaline urine promotes elimination of what kind of drugs?
Weak acidic drugs
How is a lipid-soluble drug absorbed?
Passive diffusion
