Pharm - Ch. 04 Word Scramble

Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size Small Size show me how

Pharm - Ch. 04

Pharmacokinetics

Question	Answer
List the four pharmacokinetic processes	Absorption, distribution, metabolism, excretion
What factors affect drug absorption?	Rate of dissolution/absorption, surface area, blood flow, lipid solubility, pH partioning
What is the most common method drugs use to pass through membranes?	Direct penetration across membrane
True or false: to pass channels/pores, drug must go against a concentration gradient, using energy	FALSE. Drugs passed using transport system proteins. With channels, drugs go down a concentration gradient
Do charged/ionized molecules directly pass through membranes?	No, because they are hydrophilic
What type of drugs can cross membranes easily?	Lipid-soluble drugs
How does ionization of drugs help drugs pass between membranes?	By manipulating the pH gradient between two sides of a membrane
Acidic drugs will accumulate on ____ side	alkaline
Define ion trapping	Weak acid or base moves across membrane due to change in pH, becomes charged, then drug accumulates on one side due to change in charge
What does parenteral mean in a pharmacological context?	By injection
What are the principal parenteral routes?	Intravenous, subcutaneous, intramuscular
Which type of administration results in rapid or slow pattern of absorption?	Intramuscular, subcutaneous
What are the barriers for intravenous administration?	None
What are the advantages of IV administration?	Rapid onset, precise control over amount, suitability for use with large volumes of fluid and irritant drugs
What are the disadvantages of IV administration?	High cost, difficulty, inconvenience, danger because of irreversibility, and potential for fluid overload, infection, embolism
What are the advantages of IM/subQ administration?	Suitability for water-soluble drugs and suitability for depot preparations
What are the disadvantages of IM/subQ administration?	Inconvenience and potential for discomfort
What are the advantages of PO administration?	Ease, convenience, economy, safety
What are the disadvantages of PO administration?	High variability, possible inactivation by stomach acid, digestive enzymes, and liver enzymes.
True or false: preparations of a drug do not have the same bioavailability if they are absorbed at same rate and same extent	False
What are the factors affecting drug distribution?	Blood flow to tissue, capillary beds, blood-brain barrier (lipid-soluble), placental drug transfer, protein binding
Is binding to albumin reversible?	Yes
P450 proteins do what to drugs?	Metabolize by chemically modifiying. Can result in toxic metabolite buildup if there are toxic levels of drug.
Drug metabolism helps with accelerated drug (A), drug (B), increased (C), activation of (D), and (E) variations	(A) excretion, (B) inactivation, (C) therapeutic action, (D) prodrugs, (E) toxicity
At what age does the liver fully develop metabolizing capacity?	After 1 year
What is the first-pass effect?	Rapid hepatic inactivation of certain PO administered drugs. (Meaning drug never reaches site of action)
What are the three renal processes for drug excretion?	Glomerular filtration, passive tubular reabsorption, active tubular secretion
What are some examples of nonrenal drug excretion?	Bile, breast milk, lungs, sweat, saliva
Why monitor plasma levels to determine therapeutic range?	Plasma levels easiest to accurately measure
What is the difference between loading dose and maintenance dose?	Loading dose is a large initial dose of drug used to achieve plateau more quickly. Maintenance dose keeps drug levels at plateau.
Define drug half-life	The time for amount of drug in body to decrease by 50%
Explain why drug-metabolizing enzymes have therapeutic consequences	A drug can increase rate of its own metabolism, necessitating increase in dosage to maintain therapeutic effects. Drug-metabolizing enzymes can accelerate metabolism of other drugs, which necessitates increase in their dosages too.
True or false: enteric-coated oral formulations are designed to release their contents in stomach	False. Designed to release in small intestine
True or false: membranes of placenta constitute an absolute barrier to passage of drugs	False. Same factors determine drug movements across all other membranes apply
What is the blood-brain barrier describing?	Tight junctions between cells that compose capillary walls of CNS. Drugs must pass through cells of capillary wall to reach CNS instead inbetween.
What is enterohepatic recirculation?	Drugs entering intestine in bile can be reabsorbed back into portal blood
How many half-lives does it take for a drug to be cleared or reach a plateau?	4
If plasma drug levels fluctate too much, what three interventions can be used?	1) give smaller doses at shorter intervals with same total daily dose; 2) use continuous infusion, 3) use a depot preparation
True or false: drug A is given at 100x the dose of drug B. Drug A will take more time to reach plateau	False. Time to reach plateau is independent of dosage size

Created by: choel on 2012-01-27