951.Volume of distribution
A.Is directly proportional to concentration
B.May be defined only in respect to blood
C.Can vastly exceed any physical volume in the body
D.Is not influenced by plasma binding
E.Has no influence on the half life

952.About potency and efficacy, the following are true except
A.Efficacy is more important than potency
B.Potency is the concentration/dose required to produce a given effect
C.Steep dose-response curves are a concern in low therapeutic index drugs
D.Low potency is not important
E.Efficacy is determined by receptors

953.The following adrenoreceptors use phospholipase as a 2ndmessenger
A.α1
B.α2
C.β1
D.β2
E.DA

954.Clearance of which drug involves capacity limited elimination
A.Phenytoin
B.Theophylline
C.Propranolol
D.Lithium
E.Gentamicin

955.Regarding biotransformation
A.Phase I reactions always precede phase II
B.Skin is an organ involved in biotransformation of drugs
C.Water conjugation is phase I biotransformation
D.CYP2D6 accounts for the majority of P450 activity
E.Epoxidation is phase II biotransformation

956.Regarding elimination kinetics
A.For most drugs the rate of elimination = clearance X half-life
B.In flow dependent elimination the limiting factor is the volume of distribution
C.Capacity limited elimination is also known as Michaelis-Menton elimination
D.Most drug pathways are not saturated at very high doses
E.The 2 major sites of drug elimination are the kidneys and the lungs

957.Clearance
A.Describes the irreversible elimination of a drug from the body
B.Describes the renal elimination of a drug from the body
C.Is the amount of drug cleared by the body per unit time
D.Has little clinical significance
E.Is not a determinant of steady state concentration

958.The volume of distribution
A.Of a drug cannot be smaller than the body’s blood volume
B.Of imipramine is 2100 L
C.Can be used to calculate the maintenance dose
D.Of a drug varies inversely with its half life
E.Cannot be easily calculated

959.Halflife
A.Is not affected by a drug’s lipid solubility
B.Refers to half the time taken for a drug to be eliminated
C.Is a composite pharmacokinetic parameter
D.Has no bearing on dosing frequency
E.Of phenytoin is constant

960.Pharmacokinetics
A.Is the study of drug effectson the body
B.Is boring as hell
C.Can help to determine the need to treat a patient who presents following an OD
D.Of a drug do not change in any one individual patient
E.Refers to the study of the metabolism of a drug