Pharm Quizzes Flashcards
Potency of a drug is defined as ________ and is helpful in choosing the right drug for the right patient
dose of a drug that is required to produce 50% of that drugs maximal effect
Medication A is dosed at 25mg when given IV but requires 100mg when given orally. The concept that underlies the difference in dosing is called
bioavailability
The overall ability of a drug to produce its desired effect. This is known as ____ and can be related to a number of factors including receptor availability, bioavailability, and other factors.
Efficacy
Aspirin can irreversibly bind to certain structures on the platelet that are involved in platelet aggregation. Although its not truly irreversible, it produces a very strong chemical bind through the sharing of electrons. This is known as _____ binding.
Covalent
Drugs that have an asymmetric carbon are not superimposable and are called _______ drugs. The importance of this concept is that these different shaped drugs can have different effects on the same receptor.
Chiral
You are the NP in a busy ICU. A patient has come into the ICU after overdosing on Drug-X. Drug-X has a volume of distribution of 0.6. Volume of distribution is calculated by:
the amount of drug in the body (delivered dose), divided by the plasma concentration
A drug that binds to the active site of a receptor and causes an irreversible antagonism through covalent bonding of the receptor is called _____ antagonism
non-competitive
a receptor type where a drug binds to an ion channel and causes that channel to open or close, for example acetylcholine which opens sodium channels, are considered_____
ligand gated ion channels
one of the most important organ involved in clearance of a drug is the _____ and chronic insufficiency can lead to decreased drug clearance
kidneys
cytochrome P450 are important enzymes involved in drug metabolism. The first step, or phase 1 of drug metabolism typically involves_____ which most often ______ water solubility to enhance elimination
modifying the structure via oxidation, increases
Fosphenytoin is a more water-soluble pro-drug of phenytoin. Prodrug means that:
the drug is the precursor to the parent compound and is metabolized to the parent compound after administration
The mechanism of action of phenytoin is:
sodium channel blockade which will reduce eliptogenic firing
drugs are eliminated at different rates depending on several factors. The concept of zero order kinetics can be defined as:
a constant amount of a drug is eliminated per unit time but the rate is independent of the concentration of the drug
Valproic acid is a commonly used anticonvulsant. Its mechanism of action is multifactorial and includes all of the following EXCEPT:
blockade of glutamate receptors
Many drugs will interact with the Cytochrome P450 system. If a drug has a high affinity for a certain CYP450 (i.e. CYP3A4) and that cytochrome will selectively choose to metabolize that drug over others, the result can be
accumulation of the drug that has less affinity
Benzodiazepines bind to _______ and effectively increases the frequency of chloride channel opening.
GABA
Phenobarbital is a sedative hypnotic that binds to GABA receptors but at high doses, can also block the excitatory receptor _____.
Glutamate
Tricyclic antidepressants can cause cardiac toxicity primarily through blockade of ____ channels, which results in a widened QRS, prolonged QT and risk for ventricular arrhythmia
sodium
One important lab test to follow when administering propofol is ______, as elevations can be a predictor of propofol administration syndrome
triglycerides
Lithium has a narrow therapeutic index. This means that:
the difference between a therapeutic dose and a toxic dose is small
acetaminophen has several mechanisms of action EXCEPT
blocking peripheral COX-1 and COX-2
acetaminophen toxicity occurs as a result of the metabolic process of
CYP450 metabolism
Ibuprofen is an NSAID that exerts most of its activity on ______
COX-1
Ibuprofen use can lead to gastric ulcers, particularly when used in high doses or for long periods of time. This occurs because of inhibition of _____, which are important in the production of gastric mucous.
prostacyclins
