Term
| For a continuous infusion, in order to obtain values which reflect the steady state, it is necessary to wait until how many half lives have passed before drawing blood levels? |
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Definition
| Wait until the fourth or fifth half life. |
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Term
| What effect will increasing the rate of infusion have on the time it takes to reach steady state? What effect will it have on the plasma drug concentration at steady state? |
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Definition
| no effect on time to reach steady state, it will increase concentration at steady state |
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Term
| Describe the drug-associated factors that allow drugs to permeate plasma membranes most readily. |
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Definition
| small, nonionized, lipid-soluble |
|
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Term
| Where do lipophilic drugs and calcium-binding drugs accumulate? |
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Definition
|
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Term
| You would predict that a drug with Vc=3 liters is distributed in... |
|
Definition
| plasma only (plasma volume = 3L) |
|
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Term
| How many liters of fluid does the body contain? |
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Definition
|
|
Term
| Drugs with which properties can diffuse through aqueous channels? |
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Definition
| small, hydrophilic (<200 mw) |
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Term
| Drug metabolism often refers to making a drug more... |
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Definition
|
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Term
| Phase I reactions (nonsynthetic), drugs are... |
|
Definition
| oxidized or reduced to a more polar form |
|
|
Term
| Phase II reactions (synthetic), what happens? |
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Definition
| Polar group, like glutathione, is conjugated to the drug. |
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Term
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Definition
|
|
Term
| What does CYP450 do? What Phase is this? |
|
Definition
| Oxidizes or reduces a drug through an electron transport chain which uses NADPH as a proton carrier. Phase I. |
|
|
Term
| How does alcohol tolerance occur? What else might it affect? |
|
Definition
| Induction of microsomal enzymes (P450), increased metabolism of other drugs that use P450 |
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Term
| Drugs excreted in the feces may become concentrated in the _______ first, and can be reabsorbed through the portal system. This is called.... |
|
Definition
| bile, enterohepatic circulation |
|
|
Term
| Why is the kidney a frequent site of chemical-induced toxicity? |
|
Definition
| Drugs are concentrated in the kidney |
|
|
Term
| Clearance = elimination rate (mg/hr) / _______ |
|
Definition
| drug concentration (mg/L) |
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Term
|
Definition
|
|
Term
| Name 4 microsomal oxidation reactions (Phase I) |
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Definition
| hydroxylation, deakylation, oxidation, polarizing atom exchange |
|
|
Term
| Name 2 microsomal reduction reactions (Phase I) |
|
Definition
| Azo-reduction, nitro-reduction |
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|
Term
| Phase II (synthetic) reactions are catalyzed by... |
|
Definition
| specific enzymes rather than P450 |
|
|
Term
| Name examples of phase II reactions. |
|
Definition
| Glucuronide conjugation, ethereal sulfate conjugation, acetylation, transulfuration (occurs in mitos), glutathione conjugation |
|
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Term
| What are the two most important plasma proteins with significant binding capacity? |
|
Definition
| albumin and orosomucoid (alpha1-acid glycoprotein) |
|
|
Term
| What effect on ED50 is seen when competitive antagonists are present? |
|
Definition
|
|
Term
| What is the therapeutic index? |
|
Definition
| a ratio of the TD50 or LD50 to the ED50 |
|
|
Term
| What is the therapeutic window? |
|
Definition
| The dosage range between the minimum therapeutic concentration range/dose and the minimum toxic concentration or dose |
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Term
| What is the best defined member of the drugs that use G protein receptors? How do they work? |
|
Definition
| Sympathomimetics, activate G proteins that either activate or inhibit adenylyl cyclase |
|
|
Term
| With spare receptors, is Kd greater or less than EC50? |
|
Definition
|
|
Term
| What is the Area Under the Curve (AUC) and what is it good for? |
|
Definition
| Area under a curve in a plot of plasma concentration vs time, useful for determining bioavailability |
|
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Term
|
Definition
| amount of drug in body / plasma drug concentration |
|
|
Term
| The Vd of drugs that are normally bound to plasma proteins can be altered by... |
|
Definition
| liver disease and kidney disease |
|
|
Term
| Clearance x Plasma concentration = |
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Definition
|
|
Term
| What is the formula for Half life? |
|
Definition
|
|
Term
|
Definition
| Desired plasma concentration x clearance / bioavailability |
|
|
Term
|
Definition
| Desired plasma concentration * Vd / bioavailability |
|
|
Term
|
Definition
| average dose * creatinine clearance / 100ml/min |
|
|
Term
| With constant infusion, how many half lives pass before reaching half the steady state concentration? |
|
Definition
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