Pharmacology Module 1

when the receptor site becomes active. Example: After morphine agonist attaches to a Mu receptor, the receptor activates and produces analgesia, euphoria and respiratory depression.

is the strength of attraction between a drug and its receptor.

is a measure of total systemic exposure to the drug.

is the extent a substance or drug becomes completely available to its intended biological destination. Some factors that influence bioavailability include first-pass metabolism, route of administration, and chemical properties of the drug.

is when two drugs are equal in the rate and extent to which the active pharmaceutical ingredient (API) becomes available at the site(s) of drug action.

(Drug metabolism) is the enzymatic alteration of drug structure. Most drug metabolism takes place in the liver.

is a natural protective membrane that prevents central nervous system (CNS) from toxins and pathogens in blood. 

increase the rate of hepatic metabolism decrease serum concentrations of other drugs metabolized by the same hepatic isoenzyme.

decrease the rate of hepatic metabolism and increase serum concentrations of other drugs metabolized by the same hepatic isoenzyme.

is the time it takes for the concentration of the drug in the plasma or the total amount in the body to be reduced by 50%.

the rapid inactivation of certain oral drugs

is the ability to dissolve through the lipid (fat) portion of a membrane.

 All drugs cross the placenta to some degree but several factors determine the degree of placental transfer. Major determinants include lipid/water solubility, molecular weight, degree of ionization, and protein binding. Drugs that are lipid soluble, smaller have a low ionized fraction, and non-protein bound tend to cross the placenta to a greater degree. 

is the degree to which medications attach to blood proteins within the blood plasma. A drug's efficacy may be affected by the degree to which it binds. The less bound a drug is, the more efficiently it can traverse or diffuse through cell membranes.

is a compound with little or no pharmacological activity that metabolizes inside the body and converts into a pharmacologically active drug compound. 

is the substance on which an enzyme acts

is the dosage range or blood plasma or serum concentration usually expected to achieve the desired therapeutic effect.