The Pharmacy Technician Chapter 10
Terms
undefined, object
copy deck
- What is the receptor and where is it located?
- the cellular material directly involve in the action of the drug and is located on the surfaces of cell membranes and inside cells
- When drug molecules bind with a receptor, they can cause a reaction that ____ or ____ cellular functions.
- stimulates or inhibits
- What is a drug that activates receptors and produces a response that may either accelerate or slow normal cellular processes, depending on the type of receptor involved referred to as?
- an agonist
- What is a drug that binds to receptors but does not activate them, instead blocking the receptors' action by preventing other drugs or substances from interacting with them referred to as?
- an antagonist
- What is the MEC?
- minimum effective concentration, enough drug to produce an effect
- What is the onset of action?
- When the MEC is reached
- What is the MTC?
- minimum toxic concentration, blood concentration limit beyond which there are undesired or toxic effects
- What is the therapeutic window?
- the range between the MEC and the MTC
- What is the duration of action?
- the time between the onset of action and when the MEC is reached again by the declining blood concentration level
- What are the ADME processes?
- absorption, distribution, metabolism and excretion
- What is another term for the ADME processes?
- disposition
- What are metabolism and excretion combined called?
- elimination
- What is absorption?
- the transfer of drug into the blood from an dministered drug product
- What can effect distribution?
- if the drug cannot penetrate the tissue's membranes, if there is not enough blood flow to the tissue, and drug binding to proteins in the blood or in tissues
- When acids dissociate are they ionized or unionized?
- ionized
- When bases are dissociated are they ionized or unionized?
- unionized
- Why do unionized drugs penetrate biological membranes more easily than ionized drugs?
- they are more lipid soluble, charges on biological membranes bind or repel ionized drugs, ionized drugs associate w/ water molecules, creating larger particles w/ reduced penetrating capability
- What are biological membranes composed of?
- lipids and proteins
- What is passive diffusion?
- when drugs in the body's fluids move from an area of higher concentration to an area of lower concentration until equilibrium is reached
- How do most orally administered drugs move in the body?
- from the intestine to the blood and from the blood to the site of action
- What are hydrophobic drugs?
- drugs that are lipid soluble, therefore penetrate cell membranes easier
- How do hydrophilic drugs penetrate membranes?
- they move through water-filled passages called aqueous pores
- How do drugs that cannot pass through a membrane by passive diffusion enter a cell?
- active transport
- What is the gastric emptying time?
- the time the drug will stay in the stomach before it is emptied into the small intestine
- What can affect gastric emptying time?
- the amount and type of food in the stomach, the presence of other drugs, the person's body position, and their emotional condition
- What can bile salts from the intestinal tract do to the absorption of drugs?
- they improve absorption of certain hydrophobic drugs
- What can enzymes do to the absorption of drugs?
- they destroy certain drugs and decrease their absorption
- Where do enzymes in the intestine come from?
- some are added to the intestinal tract's contents from pancreatic secretions and some are present in the intestinal wall
- What does protein binding cause?
- the drug binds w/ proteins and the molecule is too big to pass through the membrane, so it is stored in the fat and muscle and gradually released as the blood concentration of the drug falls
- What are the 2 uses for terbutaline?
- bronchodilation and to delay labor in pregnant women
- What is an example of a highly selective tissue membrane?
- the blood-brain barrier and finger and toe nails
- What happens to a drug when it binds with a protein to form a complex?
- the drug cannot pass through membranes and is inactive
- What is a metabolite?
- a drug after the body has transformed it
- What is the primary site of drug metabolism in the body?
- the liver
- What transforms a drug into a metabolite?
- enzymes
- What does enzyme induction do to the metabolism of a drug?
- it results in greater metabolism of a drug
- What is it called when drugs that have made their way to the gall bladder are emptied into the intestine after consumption of food and are reabsorbed back into the body?
- enterohepatic cycling
- What is first-pass metabolism?
- the drug must go thru the liver before reaching systemic circulation, where enzymes can degrade or destroy a drug
- If the kidney's process of filtration becomes impaired, how would this affect drug dosaging?
- excretion would be reduced and drugs will accumulate in the blood; the dosage of drugs must be decreased or the dosing interval lengthened
- Which penetrates biological membranes more easily, ionized or unionized drugs?
- unionized drugs