Key terms

Question 1

Pharmacokinetics

Answer 1

Pharmacokinetics (PK) is the study of how the body interacts with administered substances for the entire duration of exposure

Question 2

Bioavailability

Answer 2

The ability of a drug or other substance to be absorbed and used by the body.

Question 3

First passage metabolism

Answer 3

The degree of metabolic breakdown of an orally administered drug that occurs in the intestine or liver before it reaches the systemic circulation.

Question 4

Affinity

Answer 4

Affinity can be defined as the extent or fraction to which a drug binds to receptors at any given drug concentration or the firmness with which the drug binds to the receptor.

Question 5

Potency in pharmacology

Answer 5

potency is a measure of drug activity expressed in terms of the amount required to produce an effect of given intensity. So a drug with higher potency can give a stronger effect at a lower concentration and vice versa.

Question 6

efficacy

Answer 6

Efficacy describes the maximum response that can be achieved with a drug.

Question 7

EC50

Answer 7

In pharmacology, the potency of a compound is expressed as the half-maximal effective concentration (EC50), which refers to the concentration of a drug that induces a response halfway between the baseline and maximum.

Question 8

Partial agonists

Answer 8

In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist.

In a graph it will look like one Emax reaching a certain height in effect and then flattening out and the partial agonist will not reach the same height before flattening out.

Question 9

inverse agonist

Answer 9

inverse agonist is a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. So while an agonist on a graph will look like a line above the y axis 0 point and an inverse agonist below the y axis 0 point

Question 10

Explainthe difference between first and zero order kinetics.

Answer 10

First order kinetics is a type of reaction rate that is dependent on the concentration of one reactant. This means that the rate of the reaction is proportional to the concentration of one reactant. For example, if the concentration of a reactant doubles, then the rate of the reaction will double as well. First order kinetics gives curved line sines the system never becomes saturated.

Zero order kinetics is a type of reaction rate that is independent of the concentration of any reactants. This means that the rate of the reaction does not change with changes in concentration. The rate remains constant regardless of how much reactant is present. For example, if you double the amount of reactant, the rate will remain unchanged. Zero-order kinetics undergo constant elimination regardless of the plasma concentration, following a linear elimination phase as the system becomes saturated. Zero order kinetics gives straight line.

A kinetic reaction can start as a zero order and become a first order but not the other way around.