Quiz 1 Flashcards
(20 cards)
Drugs that activate receptors and mimic the actions of the body’s own regulatory molecules are called:
A. Agonist
Agonists bind to receptors and activate them, producing effects similar to the body’s natural substances.
True or False: Drugs with many receptor sites can change the function of certain cells in the body.
False
It’s not the quantity of receptor sites, but the specific receptors targeted and the effect of drug binding that determines cellular function changes.
The more potent a drug is, the greater its maximum efficacy. True or False?
B. False
Potency is about dose required for effect. Efficacy is the maximum effect achievable. A potent drug can have low efficacy.
Measuring a trough level of a drug may determine a change in the:
B. Interval
Trough levels help assess how often a drug should be given to maintain therapeutic levels without toxicity.
Elimination of drugs happens primarily via the:
B. Kidney
Most drugs are eliminated via renal excretion, though metabolism typically occurs in the liver.
Maximum efficacy refers to:
B. Maximum effect that a drug can produce
Efficacy = ceiling effect of a drug regardless of dose.
Drugs are available to exert their effect on the cell when they are:
C. Unbound to albumin
Only free (unbound) drugs are pharmacologically active and available to cross membranes.
The half-life of a drug is 2 hours. At 4 hours, the expected concentration is:
B. 25%
After one half-life (2 hours), 50% remains; after two (4 hours), 25% remains.
Passage of a drug from the site of administration into circulation is:
A. Absorption
Absorption = entry of drug into bloodstream from the administration site.
Drugs that easily cross the blood-brain barrier are:
B. Lipid-soluble
The blood-brain barrier allows lipophilic substances to pass through more easily.
The cytochrome P450 system is found in the:
B. Liver
P450 enzymes metabolize drugs in the liver, affecting their bioavailability and elimination.
Half-life is used to predict and interpret:
B. Change in plasma concentration
Half-life helps estimate how long a drug remains active and how dosing affects levels.
Drugs that prevent receptor activation but have no effects of their own are called:
B. Antagonists
Antagonists bind receptors but block activation, producing no intrinsic effect.
The therapeutic index refers to:
C. Ratio of drug’s toxic dose to its effective dose
A higher therapeutic index means a safer drug, with a wide margin between therapeutic and toxic levels.
The first-pass effect can cause a drug to be:
B. Inactivated before reaching the bloodstream
First-pass metabolism in the liver can significantly reduce oral drug bioavailability.
Intramuscular absorption depends on:
B. Blood flow to the site of injection
IM absorption is faster with greater perfusion at the injection site.
Volume of distribution is higher in neonates for drugs that are:
C. Water-soluble
Neonates have a higher total body water content, affecting water-soluble drug distribution.
What is the most crucial factor in determining drug penetration across the blood-brain barrier?
B. Lipid solubility
Lipid-soluble drugs can cross the BBB more readily than polar or large molecules.
Total body water content in ELBW infants is inversely related to gestational age, meaning:
A. As gestational age decreases, total body water increases
Preterm infants have more extracellular water, making water content higher at lower gestational ages.
Which of the following statements is true about the drug approval process?
C. Women, children, and minorities are often underrepresented in clinical trials
These populations are historically underrepresented, raising concerns about generalizability and safety in real-world use.
