Pharmacokinetics, Pharmacodynamics, Pharmacology of Autonomic nervous system drugs, Autocoids

61.    The following drugs are excreted mainly unchanged:

a.    chlorpropamide.

b.    gentamicin.

c.    diazepam.

d.    propranolol.

62.    Cumulative toxicity is more likely to occur if a drug:

a.     undergoes zero-order elimination.

b.     dissociates readily into the urine.

c.     is highly lipid soluble.

d.     undergoes entero-hepatic cycling.

63.    The plasma elimination t1/2 of a drug:

a.     is inversely related to its clearance.

b.     is shorter after intravenous compared to oral administration.

c.     is not affected by changes in its apparent volume of distribution.

d.     largely determines its duration of action.

64.   The fraction of the total receptors to which a drug is bound is a function of:

a.     the drug concentration.

b.     the maximum drug effect.

c.     the dissociation constant for the drug-receptor.

d.     the potency of the drug.

65.    A competitive antagonist:

a.      acts through the same receptors as the corresponding agonist.

b.      shifts the dose-response curve to the right.

c.      is reversible.

d.      decreases the maximal response that can be obtained from a tissue.

66.    Drug-receptor interaction:

a.      non-competitive antagonist binds irreversibly with the receptor.

b.      more potent drug is not as useful clinically as a drug that is less potent but has higher efficacy.

c.      substances that do not interact with receptors have no pharmacological effects.

d.      the magnitude of a response is directly proportional to the rate of occupation of the receptor by the agonist.

67.    The following refer to the renal clearance of drugs:

a.      highly lipid-soluble drugs undergo excretion more readily.

b.      an acidic drug with pKa 1.5 will be largely reabsorbed at urine pH 5.5.

c.      theophylline is excreted mainly unchanged.

d.      excretion can involve active as well as passive processes.

68.    With regards to binding of drugs to plasma proteins:

a.      binding tends to limit the the elimination of drugs which undergo renal tubular secretion.

b.      the greater the degree of binding of a drug, the longer will be its half-life.

c.      hypoalbuminaemia can cause an increase in total plasma concentration of some drugs.

d.      a drug with a low binding capacity is more likely to cause adverse effects when displaced from binding. 

69.    The following decrease intra-ocular pressure:

a.      pilocarpine.

b.      tropicamide.

c.      timolol.

d.      promethazine.

70.    The following drugs can cause mydriasis:

a.      atropine.

b.      physostigmine.

c.      morphine.

d.      ephedrine.

<< Last Page                             Answers                     Next Page >>