Pharmacokinetics

Anesthesia Pharmacology Chapter 2: Pharmacokinetics Practice Questions

Choose the correct answer for each question.

Drug(s) with high extraction by the liver:
1. imipramine (Tofranil)
2. meperidine (Demerol)
3. propranolol (Inderal)
4. amitriptyline (Elavil, Endep)
5. isoniazid (INH)
Drugs poorly extracted by the liver:
1. digitoxin (Crystodigin)
2. diazepam (Valium)
3. meperidine (Demerol)
4. chlorpropamide (Diabinese)
First pass pulmonary uptake > 65% of dose
1. lidocaine (Xylocaine)
2. fentanyl (Sublimaze)
3. propranolol (Inderal)
4. alfentanil (Alfenta)
5. meperidine (Demerol)
Factors that affect first pass pulmonary effect magnitude
1. spontaneous respiration
2. control ventilation
3. apnea
4. none of the above
Large volumes of distribution:
1. associated with chloroquine (Aralen)
2. suggests minimal tissue binding
3. both
4. neither
Factor(s) influencing the volume of distribution:
1. patient's gender
2. patient's age
3. patient's disease state
4. patient's body composition
5. all the above
Factor(s) influencing clearance (CL):
1. elimination rate constant
2. volume of distribution
3. both
4. neither
Most important organ for unchanged drug/drug metabolite elimination
1. liver
2. lung
3. kidney
4. none of the above
Glomerular filtration:important factors
1. extent of drug-protein binding
2. glomerular filtration rate
3. both
4. neither
Passive renal tubular reabsorption:
1. enhance lipid solubility favors excretion
2. renal tubule or reabsorption rate influenced by rate of renal tubular urine flow
3. both
4. neither
Factor(s) influencing renal clearance:
1. carrier saturation
2. extent of drug-plasma protein binding
3. volume filtered in the glomerulus
4. blood flow
5. number of functional nephrons
Factor(s) affecting hepatic clearance:
1. extent of blood flow to the liver
2. extent of plasma protein bound drug
3. both
4. neither
Drugs which exhibit clearances > 6 ml/min./kg
1. diltiazem (Cardiazem)
2. verapamil (Isoptin, Calan)
3. lidocaine (Xylocaine)
4. meperidine (Demerol)
5. morphine
Factor(s) which may change intrinsic drug clearance:
1. smoking
2. dietary considerations
3. age
4. genetic factors
5. all the above
Capacity-limited elimination
1. aspirin
2. saturable process
3. both
4. neither
Half-life = time required to decrease in other drug in the body by 50% during elimination. Assumption(s):
1. single body compartment size =apparent volume of distribution
2. blood or plasma is considered in equilibrium with a total apparent volume of distribution
Factor(s) influencing drug half-life:
1. chronic renal failure
2. age
3. plasma protein binding
4. none of the above
The definition of "context-sensitive" halftime is the length of time required for drug plasma concentration to fall 50% after continuous infusion
1. true
2. false
Number of half-lives required to go from one steady-state to another:
1. 1
2. 2
3. 4
4. 8
Bioavailability < 100% following oral dose administration:
1. incomplete absorption
2. first pass effect
3. both
4. neither
Absorption rate proportional to the drug concentration dissolved in the gastrointestinal tract
1. zero order
2. first order
3. neither
Termination drug action
1. usually by biotransformation followed by excretion
2. sometimes by redistribution from the drug site of action to other tissues or sites
3. both
4. neither
Drug-plasma protein binding
1. most drugs are bound to plasma protein
2. alpha1-acid glycoprotein increases following surgery, myocardial infarction, and in response to chronic pain
3. renal failure may affect drug bound fraction
4. drug-plasma albumin binding is typically very selective
Renal clearance
1. influenced by renal disease
2. affected by the number of functional nephrons
3. altered by blood flow
4. all of the above
Biotransformation: tends to convert a drug to a more hydrophobic (lipophilic) metabolite
1. true
2. false
Parent drug is altered by introducing or exposing a functional group such as -OH or NH2
1. Phase I
2. Phase II
Phase II characteristics: parent compound functional group linkages with
1. sulfate
2. glucuronic acid
3. acetate
4. amino acids
5. glutathione
Property/properties of phase II conjugates:
1. relatively nonpolar
2. generally biologically active
3. rapidly excreted in the urine
4. all of the above
Principal organ for biotransformation of drugs:
1. kidney
2. lung
3. liver
4. skin
Factor/factors which may reduce drug bioavailability:
1. exposure to digestive enzymes
2. gastric acid instability
3. absence of intestinal flora (bacteria)
4. first pass effect
Localization of mixed function oxidase system:
1. smooth endoplasmic reticulum membranes
2. rough endoplasmic reticulum membranes
Important microsomal enzyme/enzymes for drug biotransformation
1. flavoprotein NADPH cytochrome P450 reductase
2. cytochrome P450
3. both
4. neither
Drug mechanism/mechanisms which may increase the amount of cytochrome P450 enzyme:
1. increased enzyme degradation rates
2. increase enzyme synthesis rate
3. both
4. neither
glucuronidation:
1. morphine
2. epinephrine
3. dopamine (Intropin)
4. histamine