| Question | Answer |
| What is Half-life? | the amount of time it takes for the plasma concentration or the amount of a drug in the body (after absorption and distribution) to be reduced by 50 percent. |
| The process of the drug returning to the blood stream before reaching the urine is known as what? | reabsorption |
| A decrease in clearance and an increase in half-life could lead to what? | toxicity (in some cases) |
| The passage of active, unchanged drug from the blood stream through the glomerulus into the urine is called? | Filtration |
| What are two examples of prodrugs? | Cortisone and prednisone |
| What is half-life dependent upon? | clearance |
| Clearance of a medication refers to? | the volume of blood that is completely cleared of the drug per unit time |
| What is a prodrug? | a medication that is pharmacologically inactive when administered, but is quickly metabolized to an active form. |
| How would a decrease in clearance affect the half-life of a drug, and how will that affect the drug concentration in the blood? | It will increase the half-life, drug concentration will be increased as well. |
| What is the primary protein that drugs may bind to and where is it made? | albumin, in the liver |
| What is the most important group of enzymes for drug metabolism? | cytochrome P450 enzymes |
| When does a drug reach steady state? | when the amount of drug being administered equals the amount being eliminated. |
| Which will have an affect on the bioavailability of a drug, reduced rate of absorption or reduced extent of absorption? | reduced extent of absorption |
| What is the definition of pharmakokinetics? | the effects of the body on drugs |
| In general, medications with a long half-life will have a dosing interval of what? | once per day |
| What are the four components of pharmakokinetics? | absorption, distribution, metabolism, and excretion |
| Where does the vast majority of drug metabolism take place? | in the liver |
| Enzymes, which are proteins, are usually responsible for? | The biotransformation of medications |
| What would the bioavailability of an IV drug be? | 100% (all of the drug reaches systemic circulation) |
| What is bioavailability? | the amount - stated as a percentage - of a drug that reaches the systemic circulation after extra-vascular administration. |
| Biotransformation metabolizes active drug to one of three things. What are the three things the drug could be metabolized to? | Less active compound, Inactive compound, or Another active compound. |
| Drugs must be in which form to be active and have a therapeutic effect? | free(unbound) |
| Renal elimination/excretion involves one or more of three processes....what are they? | Filtration, Active secretion, and reabsorption |
| In general, medications with a shorter half-life will have a dosing interval of what? | twice per day or three to four times per day |
| Drugs "exist" in one of two "forms" while they are in the body....what are they? | free(unbound,not protein bound) or protein bound |
| The secretion of active, unchanged drug into the filtrate (and eventually into the urine) is called? | Active secretion |
| In general how many half lives does it take for a drug to reach steady state? | 5 |
| What is the first-pass effect? | a phenomenon of drug metabolism whereby the concentration of a drug is greatly reduced before it reaches the systemic circulation. |
