981.Which is true
A.Zero order kinetics refers to situations where a constant proportion of the drug in the body is eliminated per unit time
B.Non-linear kinetics are best described in situations where no matter how much drug is in the body a constant amount of drug is eliminated per unit time
C.Variations in the dose of ETOH will not effect its half life
D.For drugs which exhibit capacity limited elimination, clearance will be constant
E.If drug doses are repeated, the drug will accumulate in the body onlyif the dosing intervals is less than 3 half lives

982.Which is incorrect
A.A drug which binds to a receptor and produces a maximal response is called a full agonist
B.A drug which binds to a receptor and produces a variable response is called a quasi agonist
C.A drug which binds to a receptor and produces a submaximal response is called a partial agonist
D.A drug which binds to a receptor and produces no response is called an antagonist
E.A drug which does not bind to receptors can still be effective

983.Which is false
A.Partial agonists produce lower response at the same receptor occupancy rate
B.The concept of spare receptors refers to the fact that some receptors have alternate molecular configuration (isomers) and so are spared from producing a response to certain drugs
C.The efficiency of the receptor-effect coupling is dependant on the affinity of the drug for the receptor, the power of the agonist and the receptor concentration
D.variation in concentration of endogenous receptor ligand may be responsible for variations in drug effectiveness
E.changes in components of the response distal to the receptor are the largest and most important group of mechanisms of variability

984.Which is true
A.The ED50is the dose at which the desired effect is produced in 50% target population
B.Maximal potency refers to the relative position of the plateau portion of the dose-response curve
A.A quantal dose-response curve plots the percentage of a population having a defined clinical response to a drug concentration or dose
D.Drugs with steep dose response curves have wide therapeutic windows
E.The ED50can be used to assess the clinical efficacy of drugs

985.Antagonists may be all of the following except
A.receptor antagonists
B.chemical antagonists
C.physiological antagonists
D.electrical antagonists
E.none of the above

986.The volume of distribution
A.Is calculated by dividing amount of drug by its clearance
B.If high suggests homogenous distribution throughout the tissues
C.If low suggests homogenous distribution through tissues
D.Of aspirin is greater than pethidine
E.Of midazolam is greater than that of Warfarin

987.The volume of distribution
A.Is less than 70L for fluoxetine
B.Is calculated by dividing the rate of elimination by concentration
C.Is inversely proportional to half life
D.Is about 5L/kg for pethidine
E.Is effected by the route of administration

988.The bioavailability of a drug
A.Must be 100% if given by inhalation
B.Is typically 75% for IV
C.Is high if the drug is hydrophilic
D.Is equal to 1 –extraction rate
E.Is 70% for oral digoxin

989.Type I biotransformation reactions include
A.Methylation
B.acetylation
C.oxidation
D.Glucuronidation
E.sulphonation

990.With regard to a drug
A.LD50 is 50% of the dose necessary to kill experimental animals
B.Efficacy is the maximum response produced by a drug
C.Spare receptors are present if Kc50 = EC50
D.Potency is the same asaffinity
E.TD50 is the concentration of a drug necessary to produce toxic effects 50% of the time

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