General Pharmacology MCQS (FCPS Part 1)

General Pharmacology MCQS (FCPS Part 1)

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This content in this book is taken from the book “FCPS Pretest Series – Minor Subjects”. To purchase the book, click here (opens in a new tab)

This post contains three sections:

  1. How to cover Pharmacology in one day
  2. Drugs of choices (taken from past FCPS Part 1 MCQs)
  3. General Pharmacology MCQs with explanations

Section 1. How to cover Pharmacology in one day

“FCPS Pretest Series” never suggests short-cuts but if you are short of time and you have are already thinking about skipping Pharmacology, then this method may help you.

A. General Pharmacology

For General Pharmacology, the MCQs and theory in this post are enough.

B. Special Pharmacology

For special Pharmacology, first mark all MCQs of a chapter in first aid. If any thing is missing from first aid, add it. Then give a read to whole chapter in first aid and literally memorized the marked stuff. The Pharmacology MCQs in “FCPS Pretest Series – Minor subjects” are arranged chapter-wise. We have also posted all Pharmacology MCQs here on this website, all of which are free to access.

C. How to check whether this method is effective or not

Take about two complete papers of your speciality. Do Pharmacology MCQs from those papers. If your score is 70% or above, it means that you have successfully covered Pharmacology.

NOTE: This same method can be used for all minor subjects.

 

Section 2: Drug of choices (Very important for FCPS Part 1 exam).

Pain in mi…. Morphine
terminal cancer pt with pain….morphine
billiary collic….morphine & pethidines.aures infection….cloxacillin
swelling on dorsum of hand with 102 fever (s.aures)..cloxacillin
60 yrs old with pyogenic meningitis…. Ceftriaxone
mild heart failure as monotherapy…..ace
monotherapy for ccf….captoril
tape worm infestation….hiclosamide ( or niclosamide)
asthmatic with ihd , for b.p control on ot table…. I/v nitroprusside
tonic clonic seizures ( after half an hout of effort with another drug)…lorazipam
hypertensive crisis …captopril
hypercalcemia due to pth overactivity…. Furosemide
anterior wall mi with pulmonary edema…furosemide
cld with gi bleeding…..inj. Terlipressin
meningitis in elderly with no drug allergy….penicillin
gas gangrene ….penicillin
sore throat , fever , joint pain ( r.f)…….benzyl penicillin
vasodilator for rx of angina that doesn’t increase hr….meraprolol
traveler’s diarrhoea…diphenoxylate
mrsa…..cotrimoxazoleItching in eyes & keratitis (hsv) …..trifluridine
chest injury & rib fracture , for local anaesthesia …..bupivacain
motion sickness…. Scopolamine ( if not given then cyclizine)
atrial filbrillation….digoxin
pulmonary anthrax….cipro
metastatic pleural effusion….bleomycin

 

Section 3: General Pharmacology MCQs with explanations.

1. Half life of a drug is 2 mins . How long it will take to reach steady state concentration

a. 4 mins

b. 9 mins

c. 16 mins

d. 25 mints

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Ans. B

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STEADY STATE CONCENTRATION

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DEFINITION: When the rate of drug input is equal to the rate of drug elimination, steady state has been achieved.

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EXPLANATION: Another way to think of this is imagine a carton of eggs in your kitchen. And imagine that you use 2 eggs to make an omelette for breakfast. Someone in your house notices the empty spots in the carton of eggs and purchases 2 more eggs and places them in the carton. So when you wake up the next morning, the carton is full of eggs. If this process repeats itself over many days, it would appear that the eggs never change … there are always 12 eggs in the carton even though you use them for various meals and recipes. In this hypothetical scenario, the eggs are at steady state because the rate of elimination is equal to the rate of input.

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The eggs represent individual drug molecules in the body. Using the eggs represents the variety of clearance mechanisms that eliminate drug molecules from circulation. And the replenishment of eggs represent taking new doses of medication.

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TIME TO REACH STEADY STATE: The time to reach steady state is defined by the elimination half-life of the drug. After 1 half-life, you will have reached 50% of steady state. After 2 half-lives, you will have reached 75% of steady state, and after 3 half-lives you will have reached 87.5% of steady state. The rule of thumb is that steady state will be achieved after 5 half-lives (97% of steady state achieved). So:

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Steady state concentration = Half life X 5 = 2 X 5 = 10 min

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2. Complete drug elimination occurs in.

a. 2 half lives

b. 2-3 half lives

c. 3-4 half lives

d. 4-5 half lives

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Ans. D

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HALF LIFE OF A DRUG ()

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  • This is the period of time required for the concentration or amount of drug in the body to be reduced by one-half.
  • A drug molecule that leaves plasma may have any of several fates. It can be eliminated from the body, or it can be translocated to another body fluid compartment such as the intracellular fluid. The removal of a drug from the plasma is known as clearance and the distribution of the drug in the various body tissues is known as the volume of distribution. Both of these pharmacokinetic parameters are important in determining the half life of a drug.

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    RULE OF FIVE

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  • Generally: 5 X half life = time at which the drug is “completely” (97%) eliminated from the body (assuming that the drug was given in a single dose)
  • 1 x ½ life – 50% of the original drug removed
  • 2 x ½ life – 75%
  • 3 x ½ life – 87%
  • 4 x ½ life – 94%
  • 5 x ½ life – 97%

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    3. Glucuronide conjugation of drugs

    a. Causes inactivation of drug

    b. Is Type 1 reaction

    c. Makes drug insoluble in water

    d. Increases its effects

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Ans. A

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GLUCORONIDATION

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  • Glucuronides are formed when a glucuronic acid is bound to a drug.
  • Glucuronidation is one of the main phase 2 metabolic pathways by which an organism transforms a small molecule drug into a more water soluble substance which enable its detoxification and further excretion.
  • Glucuronides are formed enzymatically by the UDP-Glucuronosyltransferases which have been reported active in the liver, kidneys, epithelial cells of the lower gastrointestinal tract and the brain.

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    4. Addition of qlucoronic acid to drug

    a. Makes drug more toxic

    b. Make it more water soluble

    c. Is a phase 1 reaction

    d. Require P450

    e. Is same in children and

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Ans. B. Refer to the above MCQ.

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5. Therapeutic Index of a drug indicates its

a. Effectivity

b. Efficacy

c. Potency

d. Toxicity

e. Safety

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Ans. E

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THERAPEUTIC INDEX (TI)

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  • The therapeutic index (TI) (also referred to as therapeutic ratio) is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes toxicity.
  • The larger the therapeutic index (TI), the safer the drug is.

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    6. Pharmacokinetic interaction among drugs is exemplified by :

    a. Shortening of action of Procaine by Adrenaline

    b. Increase peripheral toxicity of Levodopa with Carbidopa

    c. Increase toxicity of Methotrexate by Aspirin

    d. Prevention of Nitroglycerine induced tachycardia by Propranolol

    e. Blockade of acetylcholine receptors by atropine

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Ans. E/C ???

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PHARMACODYNAMICS: Pharmacodynamics is the study of how a Drug affects an organism (i.e., the effects of drugs and the mechanism of their action).

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PHARMACOKINETICS: (Kinetics = movement) Pharmacokinetics is the study of how the organism affects the drug (i.e., the study of the “movement” of drugs in the body, including the processes of absorption, distribution, localization in tissues, biotransformation, and excretion).

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DRUG-DRUG INTERACTION

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  • It is a situation when one drug affects the activity of another drug when both are administered together.
  • This action can be synergistic (when the drug’s effect is increased) or antagonistic (when the drug’s effect is decreased) or a new effect can be produced that neither produces on its own.

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    DRUG INTERACTIONS: PHARMACOKINETIC VS PHARMACODYNAMIC

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    Drug interactions can be pharmacokinetic or pharmacodynamic.

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    (1) PHARMACOKINETIC INTERACTION

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  • With a pharmacokinetic interaction, one drug affects the other’s absorption, distribution, metabolism, or excretion.
  • An example occurs when a patient takes the antibiotic ciprofloxacin with olanzapine, a drug used to treat schizophrenia. Ciprofloxacin blocks the enzyme that breaks down olanzapine; this results in high blood levels of olanzapine, which in turn may cause muscle spasms and predispose the patient to falls.

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    (2) PHARMACODYNAMICS INTERACTION

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  • In a pharmacodynamic interaction, two drugs have additive or antagonistic effects.
  • For example, if ciprofloxacin is given with glibenclamide (an antidiabetic), it may increase the antidiabetic effects of glibenclamide, possibly causing profound hypoglycemia.

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    7. Best example of pharmacokinetics drug drug interaction is

    a. increase action of procain by epinephrine

    b. Toxicity of lithium with thiazide diuretics

    c. Reverse the action of aspirin by NaHCO3

    d. Reverse the action of Morphine by Naloxone

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Ans. D

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8. Volume of distribution is affected by all except:

A. Age

B. Liver disease

C. Renal disease

C. Lung disease

D. Sex

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Ans. E

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DRUG DISTRIBUTION

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It is the process by which the drug leaves blood circulation and enters the interstitium (i.e., the spaces between the cells) and/or the cells of the tissues.

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VOLUME OF DISTRIBUTION (Vd)

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  • It is defined as the distribution of a medication between plasma and the rest of the body after oral or parenteral dosing.
  • The VD of a drug represents the degree to which a drug is distributed in body tissue rather than the plasma. A drug with higher Vd will have higher concentrations in tissues than in plasma (e.g., phenytoin, morphine, digoxin). A drug with low Vd is mainly confined to the plasma (e.g., heparin, insulin).
  • Large Vd means “long duration of action”.

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    FACTORS AFFECTING VOLUME OF DISTRIBUTION

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    (A) CARDIAC OUTPUT AND BLOOD FLOW

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    ↑Cardiac output → ↑Blood flow to the tissues → ↑Distribution of drug from plasma to interstitial fluid.

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    (B) PHYSIOCHEMICAL PROPERTIES OF THE DRUG

    (1) Molecular weight: A drug with higher molecular weight can not easily pass from blood to the interstitium; so higher is the molecular weight of the drug, lower will be its Vd.

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    (2) Lipid solubility: As cell membranes are mainly made up of lipids, lipid-soluble drugs can easily pass through the cell membranes, and hence have a high Vd. In contrast, water-soluble drugs can not easily pass through cell membranes, and hence have a low volume Vd.

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    (C) CAPILLARY PERMEABILITY

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  • Endothelial cells of capillaries have wide slit junctions that allow easy movement and distribution of drugs.
  • Greater is the capillary permeability, greater will be its Vd.

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    (D) PLASMA PROTEIN BINDING

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  • Drugs can bind to plasma proteins (Acidic drugs bind to Albumin while basic drugs to glycoproteins).
  • If a drug has higher plasma proteins binding capability, it can not easily pass from blood to the tissues, and hence, have a low Vd.

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    (E) TISSUE BINDING

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  • Drugs can bind to specific tissues. For example:

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  • Tetracyclins bind to bone.
  • Iodides accumulate in salivary and thyroid glands.

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  • The greater is tissue binding of the drug, hiher will be its concentration in the tissues (than in blood), and hence higher will be its Vd.

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    (F) RENAL FAILURE

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    Renal failure causes fluid retention in the body, thus increasing Vd of the drug.

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    (G) LIVER FAILURE

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  • Proteins are synthesized in the liver.
  • In liver failure, proteins synthesis is decreased, resulting in decreased plasma proteins binding of the drugs, and hence, increased Vd.

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    9. Distribution of drug is enhanced by

    a. Ionized state

    b. Lipid solubility

    c. Electric equivalence

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Ans. B. Refer to the above MCQ.

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10. Basic drug binds to

a. Alpha glycoproteins

b. Albumin

c. Globulin

d. Hetoglobin

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Ans. A. Acidic drugs bind to Albumin, while basic drugs bind to alpha glycoproteins.

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11. Protein bound fraction of the drug is

a. Active

b. Inactive

c. More lipid soluble

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Ans. B. The free form of drug is pharmacologically active, while the bound form of drug is pharmacologically inactive.

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12. If a drug is taken orally, How will u assess the drug

a. Plasma drug concentration

b. Blood drug concentration

c. Urine drug concentration

d. Sweat concentration

e. Stools drug concentration

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Ans. A. PLASMA DRUG CONCENTRATION: It is the amount of drug in a given volume of plasma (e.g., number of micrograms per milliliter). Therefore, an orally taken drug can be assessed by its plasma concentration.

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13. A highly ionized drug:

a. Is excreted mainly by the kidney.

b. Can cross the placental barrier easily.

c. Is well absorbed from the intestine.

d. Accumulates in the cellular lipids.

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Ans. A

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  • Kidney is the main organ for excretion of drugs from the body.
  • An ionized drug is easily filtered, and poorly reabsorbed in the kidneys, thereby increasing its excretion.

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    14. Most of drugs are metabolized in

    a. Heart

    b. Liver

    c. Kidney

    d. Lungs

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Ans. B

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  • Liver is the principal site for metabolism of drugs.
  • Cytochrome P450 or microsomal pathways are used to metabolize most of the drugs.

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    15. Enzyme induction occurs in:

    a. Liver

    b. Kidney

    c. Heart

    d. Adrenals

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Ans. A.

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ENZYME INDUCTION (Induction = increase in)

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DEFINITION: It is the process by which a drug increases the metabolic activity of an enzyme either by binding to the enzyme and activating it, or by increasing the expression of the gene coding for the enzyme.

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SITE: Enzyme induction mainly occurs in the “liver”.

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EFFECTS: Drugs which induce hepatic enzymes may have the following effects:

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  • They may decrease the bioavailability of other drugs which are metabolised by those enzymes.
  • They may increase the bioavailability of drugs which require metabolism for their activation

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    EXAMPLES: Examples of enzyme inducers include:

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  • Long term alcohol abuse
  • Rifampicin
  • Anticonvulsants, particularly phenytoin, carbamazepine, phenobarbitone and primidone
  • Spironolactone
  • Griseofulvin

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    16. The bioavailability of a drug determines

    a. Efficacy

    b. Efficiency

    c. SAFETY

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Ans. A

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EFFICACY

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  • Efficacy (Emax) is the “maximum effect” that a drug can produce regardless of dose.

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    BIOAVAILABILITY

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  • Bioavailability (BA) is the fraction of an administered dose of unchanged drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. However, when a medication is administered via other routes (such as orally), its bioavailability generally decreases (due to incomplete absorption and first-pass metabolism).
  • If a drug has high bioavailability, it means a higher amount of the administered drug reaches the systemic circulation, and hence, the drug will have higher efficacy.

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    17. Therapeutic dose can be measured by

    a. Plasma half life

    b. Potency

    c. Efficacy

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Ans. B

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Therapeutic dose

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  • Therapeutic dose is the amount (dose) of the drug required to produce a desired effect.

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    POTENCY

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  • Potency is the amount (dose) of a drug that is needed to produce a given effect.
  • A highly potent drug (e.g., fentanyl, alprazolam, risperidone) evokes a given response at low concentrations, while a drug of lower potency (codeine, diazepam, ziprasidone) evokes the same response only at higher concentrations.

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  • A drug may have higher potency but least efficacy, which means that the response is seen at very lower doses and remains very small even at higher doses.
  • Therapeutic dose is directly proportional to potency of the drug, i.e., if a drug is highly potent, only a small amount (dose) of the drug will be required to produce a desired effect.

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    18. Regarding efficacy and potency of a drug, all are true except:

    a. In a clinical setup, efficacy is more important than potency

    b. In the log dose response curve, the height of the curve corresponds with efficacy

    c. ED50 of the drug corresponds to efficacy

    d. Drugs that produce a similar pharmacological effect can have different levels of efficacy

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Ans. C

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ED50 (MEDIAN EFFECTIVE DOSE)

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  • The median effective dose is the dose that produces an effect in 50% of the population that takes it.
  • It is also sometimes abbreviated as the ED50 , meaning “effective dose, for 50% of people receiving the drug”.
  • So, the ED50 of the drug is a measure of the drug dose. It reflects the potency of the drug, and tells nothing about its efficacy.

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    19. ED50 is a measure of:

    a- Toxicity

    b- Safety

    c- Potency

    d- Efficacy.

    Ans. C. Refer to the above MCQ.

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    20. Coronary steal commonly is seen with:

    a. Atenolol

    b. Diltiazem

    c. Nitroglycerine

    d. Dipyridamole

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Ans. D

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CORONARY STEAL

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  • Coronary steal is the term given to blood being stolen from one region of the coronary tree by another. It is also called coronary steal syndrome.
  • In fact, the term “steal” is used in vascular medicine for one territory stealing blood from another territory. Another example of steal is subclavian steal in which the arm steals blood from the brain so that the person feels giddiness during arm exercise. Steal occurs when there is obstruction to one vessel which is connected to another.
  • Coming back to coronary steal, it occurs when certain type of vasodilators (blood vessel dilating drugs) are given. The classical example is a drug called dipyridamole.
  • Dipyridamole is both an antiplatelet drug and a vasodilator. When it is given to a person with partial obstruction to a coronary artery, all the coronary vessels dilate. Hence blood will flow preferentially to the non-obstructed vessels, reducing the flow in the region of the obstructed vessel. Hence the drug given to improve the circulation will predispose to stealing of the blood into other regions.
  • This is why dipyridamole is not used for this purpose usually, as it further aggravates the ischemia in the region of obstructed vessels. This disadvantage can be used in the form of dipyridamole stress test to bring out the deficiency of blood supply in a suspected case, if the person is unable to undergo a treadmill exercise test due to physical deficits in the legs.
  • Another drug with similar effect is adenosine. Adenosine is used for pharmacological stress test now a days because it is short acting. Any reduction in blood supply to a region of the heart produced by adenosine is quickly reversed and unlikely to lead to long lasting cardiac damage.
  • It is also associated with the administration of Isoflurane, which is an inhaled anesthetic.
  • Hydralazine can potentially cause this condition as well, as it is a direct arteriolar vasodilator.
  • It has been associated with nitroprusside.

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    21. All are reasons for reducing drug dosage in elderly except

    a. They are lean and their body mass is less

    b. Have decreasing renal function with age

    c. Have increased baroceptor sensitivity

    d. Body water is decreased

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Ans. C. Elderly people have reduced baroreceptor sensitivity.

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22. Common sign of agranulocytosis is

a. Weight loss

b. Sore throat

c. Bleeding

d. Git upset

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Ans. B

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GRANULOCYTES

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  • Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm.

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  • They are also called polymorphonuclear leukocytes (PMN, PML, or PMNL) because of the varying shapes of the nucleus, which is usually lobed into three segments. This distinguishes them from the mononuclear agranulocytes. In common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil granulocytes, the most abundant of the granulocytes; the other types (eosinophils, basophils, and mast cells) have lower numbers.
  • Granulocytes are produced via granulopoiesis in the bone marrow.

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    AGRANULOCYTOSIS

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    DEFINITION: Agranulocytosis is the term used when the bone marrow fails to make enough granulocytes.

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    CAUSES: Agranulocytosis may may congenital or acquired. Acquired causes of agranulocytosis include:

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  • drugs, such as clozapine and antithyroid medication.
  • exposure to chemicals, such as the insecticide DDT.
  • diseases that affect bone marrow, such as cancer.
  • serious infections.
  • exposure to radiation.
  • autoimmune diseases, such as systemic lupus erythematosus.

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    SIGNS AND SYMPTOMS

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    The early symptoms of agranulocytosis may include:

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  • sudden fever
  • chills
  • sore throat
  • weakness in your limbs
  • sore mouth and gums
  • mouth ulcers
  • bleeding gums

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    Other signs and symptoms of agranulocytosis can include:

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  • fast heart rate (tachycardia)
  • rapid breathing (tachypnea)
  • Hypotension
  • skin abscesses

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    23. Which of the following is the most serious adverse drug reaction

    a. Aplastic anemia

    b. Megaloblastic anemia

    c. Thrombocytopenia

    d. Hemolytic anemia

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Ans. A. Aplastic anemia is considered the most serious drug-induced

blood disorder because of its associated high mortality rate compared with other blood disorders.

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24. In zero order kinetics, half life

a. Remains constant

b. Increases with dose

c. Decreases with dose

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Ans. B

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DRUG CLEARANCE OR ELIMINATION KINETICS (DRUG METABOLISM)

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There are two types of drug eliminations kinetics:

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(A) Zero order kinetics

(B) First order kinetics

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(A) ZERO ORDER ELIMINATION KINETICS

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DEFINITION: “Elimination of a constant quantity per time unit of the drug quantity present in the organism.”

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EXAMPLE: 1.2 mg are eliminated every hour, independently of the drug concentration in the body.

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HALF LIFE: In zero order kinetics, half life decreases with deacreasing concentration and vice versa.

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Figure: Half life in zero order kinetics

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(B) FIRST ORDER ELIMINATION KINETICS

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DEFINITION: “Elimination of a constant fraction per time unit of the drug quantity present in the organism. The elimination is proportional to the drug concentration.”

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EXAMPLE: 1% of the drug quantity is eliminated per minute. Most drugs are eliminated by first order kinetics.

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HALF LIFE: In first order kinetics, length of half life remains constant.

Figure: Half life in first order kinetics

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25. Idiosyncracy is known to have

a. Genetic component

b. Psychological component

c. Physiological component

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Ans. A

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IDIOSYNCRATIC DRUG REACTIONS

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DEFINITION

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Idiosyncratic drug reactions, also known as type B reactions, are abnormal reactions to drugs that occur rarely and unpredictably amongst the population. In contrast to side effect, an idiosyncratic drug reaction is unique to an individual.

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MECHANISM

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  • In adverse drug reactions involving overdoses, the toxic effect is simply an extension of the pharmacological effect (Type A adverse drug reactions). On the other hand, clinical symptoms of idiosyncratic drug reactions (Type B adverse drug reactions) are different from the pharmacological effect of the drug.
  • The proposed mechanism of most idiosyncratic drug reactions is immune-mediated toxicity. To create an immune response, a foreign molecule must be present that antibodies can bind to (i.e. the antigen) and cellular damage must exist. Very often, drugs will not be immunogenic because they are too small to induce immune response. However, a drug can cause an immune response if the drug binds a larger molecule.
  • Strong genetic predisposing factors have also been identified for idiosyncratic reaction to some drugs such as carbamazepine, allopurinol, flucloxacillin, and statin-induced myopathy.

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    26. Toxic hepalocellular injury is caused by the following except

    A. Halothane

    B. Isoniazid

    C. Methyl dopa

    D. Metronidazole

    E. Sulfonamides

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    Ans. D. Drugs are an important cause of liver injury. Approximately 75% of the idiosyncratic drug reactions result in liver transplantation or death. Drug-induced hepatic injury is the most common reason cited for withdrawal of an approved drug. Pathological manifestations of drug-induced hepatotoxicity are as follows:

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  • Acute hepatocellular injury
  • Acute viral hepatitis–like picture – INH, halothane, diclofenac, troglitazone
  • Mononucleosis like picture – Phenytoin, sulfonamides, dapsone
  • Chronic hepatocellular injury – Pemoline, methyldopa
  • Massive necrosis – Acetaminophen, halothane, diclofenac
  • Steatosis
  • Macrovesicular steatosis – Alcohol, methotrexate, corticosteroids, minocycline, nifedipine, TPN
  • Microvesicular steatosis – Alcohol, valproic acid, tetracycline, piroxicam
  • Steatohepatitis – Amiodarone, nifedipine, synthetic estrogens, didanosine
  • Pseudoalcoholic injury – Amiodarone
  • Acute cholestasis – Amoxicillin-clavulanic acid, erythromycin, sulindac
  • Chronic cholestasis – Chlorpromazine, sulfamethoxazole-trimethoprim, tetracycline, ibuprofen
  • Granulomatous hepatitis – Carbamazepine, allopurinol, hydralazine
  • Vascular injury – Steroids
  • Neoplasia – Contraceptives, anabolic steroids
  • Adenoma – Steroids
  • Angiosarcoma – Vinyl chloride
  • Hepatocellular carcinoma – Anabolic steroids, aflatoxin, arsenic, vinyl chloride

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    27. Following drugs may cause photosensitivity reactions, Except

    A. Amiodarone

    B. Cimetidine

    C. Quinolones

    D. Sulphonamides

    E. Tetracyclines

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Ans. B. WHAT IS PHOTOSENSITIVITY: Photosensitivity is the term used to describe sensitivity to the ultraviolet (UV) rays from sunlight and other light sources, such as indoor fluorescent light. Photosensitivity can cause rashes, fever, fatigue, joint pain, and other symptoms.

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Figure: Subacute cutaneous lupus erythematosus exacerbated by terbinafine.

DRUG-INDUCED PHOTOSENSITIVITY

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Patients with drug-induced photosensitivity often, but not always, note intolerance to sunlight. Most phototoxic reactions result from the systemic administration of drugs. Photoallergic reactions can be caused by either topical or systemic administration of the chemical.

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Table: Common Photosensitising Medications

Antibiotics

  • Tetracyclines
  • Fluoroquinolones e.g. ciprofloxacin
  • Sulfonamides

NSAIDs

  • Ibuprofen
  • Naproxen
  • Ketoprofen
  • Celecoxib

Diuretics

  • Frusemide
  • Bumetanide
  • Hydrochlorothiazide

Retinoids

  • Isotretinoin
  • Acitretin

Hypoglycemics
(Antidiabetics)

  • Sulfonylureas (e.g. glipizide, glyburide)

Neuroleptics (anticonvulsants)

  • Phenothiazines (e.g. chlorpromazine, fluphenazine)
  • Thioxanthenes (e.g. chlorprothixene)

PDT Pro-photosensitisers*

  • 5-aminolevulinic acid
  • Methyl-5-aminolevulinic acid
  • Photofrin

Other drugs

  • Amiodarone
  • Diltiazem
  • Quinine
  • Quinidine
  • Hydroxychloroquine
  • Enalapril
  • Dapsone

*Photodynamic therapy (PDT) is a treatment modality. Photoreactive chemicals are injected into the patient and irradiated with light strong enough to activate the chemicals, causing them to emit free radicals and destroy the targeted abnormal cells.

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Table: Common Photosensitising Topical Agents

Sunscreens

  • Benzophenones
  • Para-aminobenzoic acid (PABA)
  • Cinnamates
  • Salicylates

Fragrances

  • Musk
  • 6-methylcoumarin

Miscellaneous

  • 5-Fluorouracil (oral and topical)
  • Coal tar

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28. factors which regulate the renal excretion of drugs Except

A. Age of the patient

B. Degree of ionization of the drug in renal tubules

C. Glomerular filteration rate

D. Ph of renal tubular fluid

E. Route of administration

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Ans. E

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ROUTES OF EXCRETION

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(A) NON-RENAL

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  • Biliary excretion (via feces)
  • Pulmonary excretion
  • Salivary excretion
  • Mammary excretion
  • Skin/Dermal excretion

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    (B) RENAL EXCRETION

    .

  • The most important organ for drug excretion is the kidney.
  • The principle processes that determine the urinary excretion of drugs are:

    .

  • Glomerular filtration.
  • Active tubular secretion (e.g., PENICILLIN)
  • Passive or active tubular reabsorption

    .

    FACTORS AFFECTING RENAL EXCRETION OF DRUGS

    .

    (A) DRUG MOLECULAR WEIGHT

    .

  • Drugs with high molecular weight are not easily filtered through the glomeruli; so they have decreased renal excretion of drugs.

    .

    (B) DRUG LIPID SOLUBILITY

    .

  • Lipid soluble drugs can easily pass through biological membranes (e.g., cell membrane). So they have a high volume of distribution, and decreased renal excretion.
  • Water soluble drugs have low volume of distribution, and are easily filtered through the glomeruli. So they have high renal excretion.

    .

    (C) VOLUME OF DISTRIBUTION

    .

  • A drug, which has high volume of distribution (Vd), is poorly excreted.
  • Drugs which are restricted to the blood (i.e., which has low Vd) have higher excretion rates.

    .

    (E) RENAL BLOOD FLOW AND GFR

    .

  • Increased renal perfusion increases excretion rate of the drugs.
  • Increase in GFR increases filtration of drugs through glomeruli, and hence, increases drug excretion.

    .

    (F) BINDING CHARACTERISTICS OF DRUGS

    .

  • Drugs which are bound to plasma proteins have large molecules, so they are not easily filtered, and hence, are poorly excreted.
  • Only the unbound form of drugs are excreted via kidneys.

    .

    (G) BIOLOGICAL FACTORS:

    .

  • AGE:
  • Age affects the renal clearance.
  • In neoborns, renal function is 30 – 40% less.
  • In old age, GFR is reduced, and tubular function is altered.
  • So, drug excretion is comparatively poor in neonates and old people.
  • SEX:

    .

  • Drug excretion is approximately 10% lower in females.

    (E) DISEASED STATES

    .

  • Certain disease states cause renal dysfunction, thus greatly impairing renal excretion of drugs.
  • These diseases include:

    .

  • Hypertension
  • Diabetes mellitus
  • Pyelonephritis

    .

  • Uremia also impairs renal clearance of drugs.

    .

    (F) Degree of ionization

    .

  • Ionized drugs are water soluble; so they are easily filtered through glomeruli + they are poorly reabsorbed; therefore, they have high renal excretion rates.

    .

    (G) PLASMA CONCENTRATION OF THE DRUG

    .

  • Higher is the plasma concentration of the drug, higher will be its excretion.

    .

    (H) URINE Ph:

    .

    .

    .

    29. for prescribing drug rationally

    A. Non-pharmacological measures should preferably be tried first in Minor self limiting conditions

    B. One drug should be prescribed for each complaint to provide complete Relief

    C. The patient should not be informed about the possible adverse effects Of prescribed drugs

    D. Two drugs having same effects should be usually prescribed to ensure Quick recovery

    E. Use of injection should be preferred to ensure proper drug delivery

.

Ans. A

.

30. therapy with gaonadotropin may result in

A. Amenorrhea

B. Cryptorchism

C. Galactorrhea

D. Ovarian hyper stimulation

E. Thyroid gland stimulation

.

Ans. D

.

31. the anticoagulant activity of warfarin can be Potentiated by all of the following except

A. Aspirin

B. Cimetidine

C. Disulfirum

D. Phenylbutazone

E. Rifampicin

.

Ans. A

.

32. following are the teratogenic drugs except

A. Ethanol

B. Folic acid

C. Lithium

D. Valproic acid

E. Warfarin

.

Ans. B

.

33. plasma half life of a drug depends on its;

A. Dose

B. Rate of absorption

C. Rate of clearance

D. Route of administration

E. Volume of distribution

.

Ans. C

.

34. all of the following are true of drug conjugates with Glucuronic acid except;

A. Easily excretable

B. Less toxic

C. Not reversible

D. Poorly formed in neonates

E. Water soluble

.

Ans. C

.

35. diethylstillbesterol is never used in pregnant ladies Because it is associated with

A. Development of dvt

B. Feminization of extcrnal genitalia of male

C. Miscarriage

D. Vaginal cancer of female affsping

E. Virilization of external genitalia of female

.

Ans. D

.

36. A 35 year old postal worker is having signs and symptoms of common Cold alongwith mild chest pain and breathing difficulty. He is Diagnosed to be suffering from early stage of pulmonary anthrax Infection. Which of the following drugs is best suited for treating This patient:

A. Penicillin v

B. Cloxacillin

C. Ciprofloxacin

D. Nalidixicasid

E. Gentamicin

.Ans. C

.

37.. Choice of a drug when given orally is determined by:

A. Measurement of the chug in the faeces

B. Measurement of the drug in tissue fluid

C. Measurement of the drug in whole blood

D. Measurement of the drug level in plasma

E. Measurement of the drug level in urine

.Ans. D

.

38. The volume of distribution of a drug is not altered by:

A. Age

B. Cardiac failure

C. Pregnancy

D. Renal filure

E. Sex

.Ans. E

.

PHARMACOLOGY

39. plasma half life of a drug depends on its

A. dose

B. route of administration

C. rate of absorption

D. rate of clearance

E. volume of distribution

.

Ans. D

.

40. a drug which is known to undergo extensive first-pass Inactivation in liver should not be administered:

A. By inhalsation

B. Intramuscularly

C. Orally

D per rectum

E sublingually

.

Ans. C

.

41. the maximum effect (emax) achieved by a drug is a measure of Its

A. Bio-availability

B. Efficacy

C. Intrinsic activity

D. Potency

E. Safety

.

Ans. B

.

42. the antihypertensive activity of a newly introduced drug was studied In a group of patients against atenolol used in the control group. After statistical analysis, the difference in the antihypertensive Activity of the two drugs will be considered statistically significant If the p value is found to be less than:

A. 0.1

B. 0.2

C. 0.3

D. 0.05

E. 0.08

.

Ans. D

.

43. Plasma half life (t 1/2) of a drug depends on

A. Degree of first pass inactivation

B. Dose administered

C. Rate of absorption

D. Rate of elimination

E. Route of administration

.

Ans. D

.

44. drugs having short plasma half life T1/2

A. Are extensively bound to plasma proteins

B. Are freely filtered through glomeruli

C. Have low therapeutic index

D. Have low volume of distribution

E. Reach steady state concentration quickly

.

Ans. E

.

45. plasma half life of a drug depends on

A. Degree of first pass inactivation

B. Dose administered

C. Rate of absorption

D. Rate of elimination

E. Route of administration

.

Ans. D

.

46. drugs with short plasma hai.f life

A. Are usually extensively bound to plasma proteins

B. Have low volume of distribution

C. Have usually weak bases

D. Low therapeutic indexes

E. Rapidly reach steady level of concentration

.

Ans. E

.

47. plasma half life of a drug depends on its

A. Dose

B. Rate of absorption

C. Rate of clearance

D. Route of administration

E. Volume of distribution

.

Ans. C

.

48. a drug which is known to undergo extensive first-pass Inactivation in liver should not be administered

A. Sublingually

B. Intramuscularly

C. Orally

D. Per rectum

E. Sublingually

.

Ans. C

.

49. First pass metabolism of drug can be avoided and bioavailability is improved if given

A) LM

B) Oral after meat

C) Oral in slow release form

D) Oral in suspension

E) Per rectal

.

Ans. A

.

50. Therapeutic index of drug correlates with

A) Bioavailability

B) Therapeutic effect

C) Safety profile

D) Half life

E) Price

.

Ans. C

.

51. Volume of distribution of drug not affected by

A) Age

B) Gender

C) Cardiac failure

D) Pregnancy

.

Ans. B

.

MEDICINE

52. Na channels are blocked by:

A. Teradotoxin

B. Opsonin

C. Calmodulin

D. Troponin

.

Ans. A

.

53. Nerve Gas causes convulsive contraction. Which of the following is the mechanism of these agents?

A. Block of acetytochollne receptors

B. Inhibition of acetylchotinestrase

C. Inhibition of release of acetylccholine

.

Ans. B

.

54. Regarding rationale of drug prescription

A. Each drug for each symptom

B. Should be avoided in minor self limiting illness

C. Patient should be informed about the side effects

.

Ans. B

.

55. Regarding volume of distribution

A. Does not depend on protein binding

B. Calculated by dose upon concentration

C. Is not affected by fat distribution

.

Ans. B

.

56. Regarding sioavtousilrn,

A. Is amount of drug reaching blood after being inactivated In liver

B. Is amount of drug reaching blood after being inactivated in gut

C. D. Amount of active drug reaching blood

.

Ans. D

.

57. A pt is has developed digoxin toxicity his plasma level of dioxin Is 4 ng/d1(pcasma half Life of digoxin is 36h).Howimuch time Is required so that plasma level of digoxin drops To safe level of 1 ng/dt

A. 36 iv

B. 52 hr

C. 72 hr

D. 92 hr

E. 112 hr

.

Ans. C

.

58. Therapeutic index refers to

A. Amount of drug cleared

B. Safety of drug

C. Bioavaiiibity of drug

D. Efficacy of drug

.

Ans. B

.

59. A person has taken salicyctates in high quantity which drug wilt increase secretion of Salicylates in the urine

A. Frusernide

B. Nancl3

C. NH4CO3

D. Ethanol

.

Ans.C

.

60. Most drugs are given after meals to

A. Decreases absorption

B. Decrease gastric side effects

C. Increase absorption

.

Ans. B

.

61. Bioavailability of drug is best increased by

A. Via oral route

B. Slow release oral suspension

C. IV route

D. Per rectum

.

Ans. C

.

62. Regarding therapeutic index

A. Safety margin of drug

B. Indicate efficacy of drug

C. Indicates potency of drug

D. Theophylline has high therapeutic index

.

Ans. A

.

63. Regarding glucoronidation of drugs which is true

A. Increase absorbton

B. Is phase 1 reaction .(2.4.4vitti3

C. Occurs in 61 Celt cycle A-eld

D. Increase soiublity of drug there by its excertion

.

Ans. D

.

64. Distribution of a drug in body is not affected by:

A. Sex

B. Age

C. Cardiac failure

D. Renal failure

E. Pregnancy

.

Ans. A

.

65. Bioavailability is for drugs administered:

A. In,

B. Iv

C. Oral

D. Sc

E. St

.

Ans. C

.

66. Elimination of aminoglycosides antibiotics from the body in elderly is decreased due

To decreased?

A. Fat metabolism

B. Hepatic metabolism

C. Renal excretion

D. Plasma protein binding

E. Volume of distribution

.

Ans. C

.

67. Drug of choke for travelers diarrhea?

A. Aluminum hydrooxide

B. Dipheno.oxylate

C. Metaclopromide

D. Sucratfate

.

Ans. B

.

68. Ranitidine differs from cimetidine in?

A. Less potent

B. Less cns toxicity

C. Decreases Les tone

B. Decreases stomach motility

E. Decreased peripheral venous conversion

.

Ans. B

.

GYNAE

69. Therapeutic index indicate:

a) Bioavailability

b) Efficacy

c) Safety.

Ans. C

.

ANESTHESIA

70. If a drug is taken orally how will u asses the drug?

a. plasma drug conc

b. blood drug conc

c. urine drug conc

d. sweat conc..

Ans. A

.

71. Enzyme induction occurs in:

a. liver

b. kidney

C. heart

d. adrenals.

Ans. A

.

72. 10 yrs old girl from Baluchistan dofatiguw, lethargy, mild jaundice, discoloration of skin, enlarged spleen. Kb 8.0, /ACV 58, S. Ferritin 1000.Appropriate treatment?

a. deferroxarnine

b. blood transfusion

c. iron transfusion

.

Ans. A

.

.

.

TAGS: GENERAL PHARMACOLOGY MCQS WITH ANSWERS FOR FCPS PART 1 EXAM USMLE PART 1 PDF PRINCIPLES OF GENERAL PHARMACOLOGY PHARMACOLOGY PPT GENERAL PHARMACOLOGY LECTURE NOTES GENERAL PHARMACOLOGY QUESTIONS

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