Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
48 Cards in this Set
- Front
- Back
|
What is pharmacokinetics?
|
The study of plasma and tissue drug concentrations by examining the effects of drug dosage and timing.
|
|
|
What is the enteral tract?
|
The GI tract (glottis to anus). Enteral routes of administration include oral, rectal, and any tube that feed into the GI tract.
|
|
|
What are some factors influencing the degree of absorption from orally- administered drugs?
|
Solubility, disintegration, pH of tract, variability in gastric emptying and GI motility, GI blood flow, first pass effect through hepatic portal circulation.
|
|
|
What is "bioavailability"? What factors can influence it?
|
It is the % of the dose reaching the systemic circulation. It is influenced by the metabolism, excretion, different formulations, and liver function.
|
|
|
What are some advantages of giving drugs through the oral route?
|
Sterility/purity is not an issue, formulations are cheap and convenient.
|
|
|
What are some disadvantages of giving drugs through the oral route?
|
Patient must be conscious and cooperative, absorption and bioavailability are variable, potential loss through vomiting, potential for upper GI tract irritation.
|
|
|
What are some advantages of giving drugs through the rectal route?
|
Rapid absorption, less first-pass effect, good for patients with swallowing problems.
|
|
|
What is a parenteral route of administration?
|
Anything that is not the enteral route.
|
|
|
What is the sublingual route of administration? What are some of its advantages?
|
It is placing the drug under the tongue. It provides direct entry to the systemic circulation, often absorbs rapidly, has a neutral pH, and is fast, easy, and comfortable.
|
|
|
What is the difference between an IV "push" and an IV "drip"?
|
A push is a bolus injection; a drip is a continuous infusion.
|
|
|
What are some factors that affect drug distribution?
|
Solubility in fat or tissue, pH of compartments, plasma protein binding, and redistribution.
|
|
|
What difference creates the gradient through the placenta? What effect does this gradient have in terms of drug distribution?
|
The fetus has a lower pH than the mother. This can cause more drugs to accumulate at the fetus than the rest of the body.
|
|
|
What is "biotransformation," as it concerns pharmaceuticals?
|
Metabolism of the drug.
|
|
|
What is Phase I of drug metabolism?
|
The drug is made more polar by the cytochrome P450 enzyme (CYP) family.
|
|
|
What is Phase II of drug metabolism?
|
The conjugation of the drug to endogenous compounds from the liver.
|
|
|
What are metabolites?
|
The intermediates and products of metabolism.
|
|
|
Discuss the number and activity of drug metabolites.
|
They can be very numerous for a drug, and are usually inactive.
|
|
|
What are some factors that affect the rate of excretion of drugs from the kidney?
|
Renal blood flow, urinary pH, protein binding, MW of drug.
|
|
|
What role does the gallbladder play in drug excretion?
|
Some drugs are secreted into bile by the liver - some of these are reabsorbed by the stomach.
|
|
|
Define "first order elimination" of drugs. What does the log C vs. time plot look like?
|
The loss of a constant proportion of a drug over time. The plot is a straight line.
|
|
|
What are some factors that affect drug distribution?
|
Solubility in fat or tissue, pH of compartments, plasma protein binding, and redistribution.
|
|
|
What difference creates the gradient through the placenta? What effect does this gradient have in terms of drug distribution?
|
The fetus has a lower pH than the mother. This can cause more drugs to accumulate at the fetus than the rest of the body.
|
|
|
What is "biotransformation," as it concerns pharmaceuticals?
|
Metabolism of the drug.
|
|
|
What is Phase I of drug metabolism?
|
The drug is made more polar by the cytochrome P450 enzyme (CYP) family.
|
|
|
What is Phase II of drug metabolism?
|
The conjugation of the drug to endogenous compounds from the liver.
|
|
|
What are metabolites?
|
The intermediates and products of metabolism.
|
|
|
Discuss the number and activity of drug metabolites.
|
They can be very numerous for a drug, and are usually inactive.
|
|
|
What are some factors that affect the rate of excretion of drugs from the kidney?
|
Renal blood flow, urinary pH, protein binding, MW of drug.
|
|
|
What role does the gallbladder play in drug excretion?
|
Some drugs are secreted into bile by the liver - some of these are reabsorbed by the stomach.
|
|
|
Define "first order elimination" of drugs. What does the log C vs. time plot look like?
|
The loss of a constant proportion of a drug over time. The plot is a straight line.
|
|
|
What are some factors that affect drug distribution?
|
Solubility in fat or tissue, pH of compartments, plasma protein binding, and redistribution.
|
|
|
What difference creates the gradient through the placenta? What effect does this gradient have in terms of drug distribution?
|
The fetus has a lower pH than the mother. This can cause more drugs to accumulate at the fetus than the rest of the body.
|
|
|
What is "biotransformation," as it concerns pharmaceuticals?
|
Metabolism of the drug.
|
|
|
What is Phase I of drug metabolism?
|
The drug is made more polar by the cytochrome P450 enzyme (CYP) family.
|
|
|
What is Phase II of drug metabolism?
|
The conjugation of the drug to endogenous compounds from the liver.
|
|
|
What are metabolites?
|
The intermediates and products of metabolism.
|
|
|
Discuss the number and activity of drug metabolites.
|
They can be very numerous for a drug, and are usually inactive.
|
|
|
What are some factors that affect the rate of excretion of drugs from the kidney?
|
Renal blood flow, urinary pH, protein binding, MW of drug.
|
|
|
What role does the gallbladder play in drug excretion?
|
Some drugs are secreted into bile by the liver - some of these are reabsorbed by the stomach.
|
|
|
Define "first order elimination" of drugs. What does the log C vs. time plot look like?
|
The loss of a constant proportion of a drug over time. The plot is a straight line.
|
|
|
After how many half-lives is a drug considered to be "gone"?
|
4 to 5 half-lives.
|
|
|
What is "zero order elimination" of a drug? What does its log Cp vs. time scale look like?
|
It is when a constant amount of drug is eliminated per unit time. The plot is a parabola which points downwards.
|
|
|
What is the "volume of distribution"? What does a high Vd signify?
|
It is the volume in which a drug "seems" to be dissolved, based on the amount of drug given and the plasma concentration. A high Vd signifies that a lot of drug has been bound in the tissue, leaving behind little free drug.
|
|
|
What is drug clearance?
|
It indicates the volume of plasma that is cleared of a drug per unit time.
|
|
|
How does a double-compartment model of clearance differ in concept and in its log Cp vs. time graph from a single compartment model?
|
It includes a second compartment representing the tissues, not just a single compartment representing the bloodstream. Its graph has a steep, negatively-sloped "distribution phase," followed by a flatter "elimination phase."
|
|
|
Give the formulas for concentration of drug and for half-life of a drug.
|
Ct = Co * e ^ (Kel * t)
t1/2 = 0.693 / Kel |
|
|
What is a "loading dose"?
|
A high dose of a substance given right at the beginning of a drug course.
|
|
|
What is a good way to keep very stable drugs levels in an individual from the beginning of the course?
|
Use a loading dose and continuous infusion.
|
