MCQs PHARMACOLOGY: general pharmacological principles

1 `Essential drugs’ are:
A. Life saving drugs
B. Drugs that meet the priority health care needs of the population
C. Drugs that must be present in the emergency bag of a doctor
D. Drugs that are listed in the pharmacopoia of a country

2 An 'orphan drug' is:
A. A very cheap drug
B. A drug which has no therapeutic use
C. A drug needed for treatment or prevention of a rare disease
D. A drug which acts on Orphanin receptors

3 Drug administered through the following route is most likely to be subjected to first-pass metabolism:
A. Oral
B. Sublingual
C. Subcutaneous
D. Rectal

 

14 Transdermal drug delivery systems offer the following advantages except:
A. They produce high peak plasma concentration of the drug
B. They produce smooth and nonfluctuating plasma concentration of the drug
C. They minimise interindividual variations in the achieved plasma drug concentration
D. They avoid hepatic first-pass metabolism of the drug

5 In addition to slow intravenous infusion, which of the following routes of administration allows for titration of the dose of a drug with the response:
A. Sublingual
B. Transdermal
C. Inhalational
D. Nasal insufflation

6 Which of the following drugs is administered by intra-nasal spray/application for systemic action:
A. Phenylephrine
B. Desmopressin
C. Azelastine
D. Beclomethasone dipropionate

7 Compared to subcutaneous injection, the intramus-cular injection of drugs:
A. Is more painful
B. Produces faster response
C. Is unsuitable for depot preparations
D. Carries greater risk of anaphylactic reaction

 

8 Select the route of administration which carries the highest risk of adversely affecting vital functions:
A. Intra arterial injection
B. Intrathecal injection
C. Intravenous injection
D. Intramuscular injection

9 Alkalinization of urine hastens the excretion of:
A. Weakly basic drugs
B. Weakly acidic drugs
C. Strong electrolytes
D. Nonpolar drugs

10 Majority of drugs cross biological membranes primarily by:
A. Passive diffusion
B. Facilitated diffusion
C. Active transport
D. Pinocytosis

11 Diffusion of drugs across cell membrane:
A. Is dependent upon metabolic activity of the cell
B. Is competitively inhibited by chemically related drugs
C. Is affected by extent of ionization of drug mole-cules
D. Exhibits saturation kinetics

12 Which of the following drugs is most likely to be absorbed from the stomach:
A. Morphine sulfate
B. Diclofenac sodium
C. Hyoscine hydrobromide
D. Quinine dihydrochloride

 

13 Which of the following is a weakly acidic drug:
A. Atropine sulfate
B. Chloroquine phosphate
C. Ephedrine hydrochloride
D. Phenytoin sodium

14 The most important factor which governs diffusion of drugs across capillaries other than those in the brain is:
A. Blood flow through the capillary
B. Lipid solubility of the drug
C. pKa value of the drug
D. pH of the medium

15 Active transport of a substance across biological membranes has the following characteristics except:
A. It is specific
B. It is pH dependent
C. It is saturable
D. It requires metabolic energy

16 Tricyclic antidepressants can alter the oral absorption of many drugs by:
A. Complexing with the other drug in the intesti-nal lumen
B. Altering gut motility
C. Altering gut flora
D. Damaging gut mucosa

17 Bioavailability of drug refers to:
A. Percentage of administered dose that reaches systemic circulation in the unchanged form
B. Ratio of oral to parenteral dose
C. Ratio of orally administered drug to that excre-ted in the faeces
D. Ratio of drug excreted unchanged in urine to that excreted as metabolites

 

Bioavailability differences among oral formulations of a drug are most likely to occur if the drug:
A. Is freely water soluble
B. Is completely absorbed
C. Is incompletely absorbed
D. Undergoes little first-pass metabolism

The most important factor governing absorption of a drug from intact skin is:
A. Molecular weight of the drug
B. Site of application
C. Lipid solubility of the drug
D. Nature of the base used in the formulation

If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is:
A. 100 L
B. 80 L
C. 60 L
D. 50 L

The following attribute of a drug tends to reduce its volume of distribution:
A. High lipid solubility
B. Low ionisation at physiological pH values
C. High plasma protein binding
D. High tissue binding

Marked redistribution is a feature of:
A. Highly lipid soluble drugs
B. Poorly lipid soluble drugs
C. Depot preparations
D. Highly plasma protein bound drugs

 

A nonvolatile, highly lipid soluble drug is metabolized at a rate of 15% per hour. On intravenous injection it produces general anaesthesia for 10 min. Which pro-cess is responsible for termination of its action:
A. Metabolism in liver
B. Plasma protein binding
C. Excretion by kidney
D. Redistribution

The blood-brain barrier, which restricts entry of many drugs into brain, is constituted by:
A. P-glycoprotein efflux carriers in brain capillary cells
B. Tight junctions between endothelial cells of brain capillaries
C. Enzymes present in brain capillary walls
D. All of the above

Which of the following is not true of the blood-brain barrier:
A. It is constituted by tight junctions between the endothelial cells of brain capillaries and the glial tissue
B. It allows passage of lipid soluble drugs into the brain
C. It limits entry of highly ionized drugs into the brain
D. It regulates passage of substances from brain into blood

Weakly acidic drugs:
A. Are bound primarily to α1 acid glycoprotein in plasma
B. Are excreted faster in alkaline urine
C. Are highly ionized in the gastric juice
D. Do not cross blood-brain barrier

 

High plasma protein binding:
A. Increases volume of distribution of the drug
B. Facilitates glomerular filtration of the drug
C. Minimises drug interactions
D. Generally makes the drug long acting

The plasma protein bound fraction of a drug:
A. Contributes to the response at the given moment
B. Remains constant irrespective of the total drug concentration
C. Remains constant irrespective of the disease state
D. Is not available for metabolism unless actively extracted by the liver

Biotransformation of drugs is primarily directed to:
A. Activate the drug
B. Inactivate the drug
C. Convert lipid soluble drugs into nonlipid solu-ble metabolites
D. Convert nonlipid soluble drugs into lipid solu-ble metabolites

Which of the following is a prodrug:
A. Hydralazine
B. Clonidine
C. Captopril
D. Enalapril

A prodrug is:
A. The prototype member of a class of drugs
B. The oldest member of a class of drugs
C. An inactive drug that is transformed in the body to an active metabolite
D. A drug that is stored in body tissues and is then gradually released in the circulation

 

Which of the following cytochrome P450 isoenzymes is involved in the metabolism of largest number of drugs in human beings and has been implicated in some dangerous drug interactions:
A. CYP 3A4
B. CYP 2C9
C. CYP 2E1
D. CYP 1A2

The following is not true of the cytochrome P450 isoenzyme CYP2D6:
A. It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamol
B. It is involved in demethylation of codeine into morphine
C. Its altered form is responsible for poor capacity to hydroxylate many drugs including metoprolol
D. It is inhibited by quinidine

The most commonly occurring conjugation reaction for drugs and their metabolites is:
A. Glucuronidation
B. Acetylation
C. Methylation
D. Glutathione conjugation

Microsomal enzyme induction can be a cause of:
A. Tolerance
B. Physical dependence
C. Psychological dependence
D. Idiosyncrasy

The following drug metabolizing reaction is entirely nonmicrosomal:
A. Glucuronide conjugation
B. Acetylation
C. Oxidation
D. Reduction

 

Which of the following types of drug metabolizing enzymes are inducible:
A. Microsomal enzymes
B. Nonmicrosomal enzymes
C. Both microsomal and nonmicrosomal enzymes
D. Mitochondrial enzymes

Induction of drug metabolizing enzymes involves:
A. A conformational change in the enzyme protein to favour binding of substrate molecules
B. Expression of enzyme molecules on the surface of hepatocytes
C. Enhanced transport of substrate molecules into hepatocytes
D. Increased synthesis of enzyme protein

Select the drug that undergoes extensive first-pass metabolism in the liver:
A. Phenobarbitone
B. Propranolol
C. Phenylbutazone
D. Theophylline

Drugs which undergo high degree of first-pass meta-bolism in liver:
A. Have low oral bioavailability
B. Are excreted primarily in bile
C. Are contraindicated in liver disease
D. Exhibit zero order kinetics of elimination

Glomerular filtration of a drug is affected by its:
A. Lipid solubility
B. Plasma protein binding
C. Degree of ionization
D. Rate of tubular secretion

 

If a drug undergoes net tubular secretion, its renal clearance will be:
A. More than the glomerular filtration rate
B. Equal to the glomerular filtration rate
C. Less than the glomerular filtration rate
D. Equal to the rate of urine formation

The plasma half life of penicillin-G is longer in the new born because their:
A. Plasma protein level is low
B. Drug metabolizing enzymes are immature
C. Glomerular filtration rate is low
D. Tubular transport mechanisms are not well developed

If a drug is excreted in urine at the rate of 10 mg/hr at a steady-state plasma concentration of 5 mg/L, then its renal clearance is:
A. 0.5 L/hr
B. 2.0 L/hr
C. 5.0 L/hr
D. 20 L/hr

Which of the following is not a primary/fundamental, but a derived pharmacokinetic parameter:
A. Bioavailability
B. Volume of distribution
C. Clearance
D. Plasma half life

If a drug is eliminated by first order kinetics:
A. A constant amount of the drug will be elimi-nated per unit time
B. Its clearance value will remain constant
C. Its elimination half life will increase with dose
D. It will be completely eliminated from the body in 2 × half life period