Pharmacology MCQs
1. Histamine is synthesized from;
A. Nor-epinephrine
B. Histidine
C. Nor-adrenaline
D. Epinephrine
Correct Answer: (B) Histidine
Explanation: Histamine is synthesized by the decarboxylation of the amino acid Histidine, a reaction catalyzed by the enzyme L-histidine decarboxylase.
2. Prostaglandin is;
A. Neurotransmitter
B. Autacoids
C. Endocrine hormone
D. Steroid hormone
Correct Answer: (B) Autacoids
Explanation: Prostaglandins are considered autacoids (local hormones), meaning they are substances that are rapidly synthesized and released at or near the site of action and have only local, short-lived effects (e.g., inflammation, pain).
3. Arachidonic acid is precursor of;
A. Histamine
B. Epinephrine
C. Prostaglandins
D. Nor-epinephrine
Correct Answer: (C) Prostaglandins
Explanation: The eicosanoids, which include Prostaglandins, thromboxanes, and leukotrienes, are biologically active lipids derived from arachidonic acid.
4. Aspirin acts as analgesics and antipyretic by inhibiting;
A. Monoamine oxidase enzyme
B. Cyclooxygenase enzyme
C. Carbonic anhydrase enzyme
D. Lipooxygenase enzyme
Correct Answer: (B) Cyclooxygenase enzyme
Explanation: Aspirin (acetylsalicylic acid) and other NSAIDs exert their analgesic, antipyretic, and anti-inflammatory effects primarily by irreversibly inhibiting the Cyclooxygenase (COX) enzyme, which is responsible for synthesizing prostaglandins.
5. Quantal dose response relationship refers to;
A. All or non response
B. Increase the intensity of action
C. Decrease the intensity of action
D. All above
Correct Answer: (A) All or non response
Explanation: The Quantal dose-response relationship relates the dose of a drug to the frequency with which a specified therapeutic or toxic effect occurs in a population. It measures the percentage of subjects exhibiting an all-or-none response (e.g., sleeping vs. not sleeping).
6. Potency of a drug means;
A. Action of drug by a dose
B. Activity of drug per unit mass
C. Activity of a drug molecule
D. Activity of drug per unit area
Correct Answer: (B) Activity of drug per unit mass
Explanation: Potency refers to the amount of drug (mass/dose) required to produce a specific effect of a given intensity. A drug with higher potency produces the desired effect at a lower dose.
7. Efficacy refers to;
A. Potency of a drug
B. Intrinsic activity of a drug
C. Safety of a drug
D. Binding capacity of drug
Correct Answer: (B) Intrinsic activity of a drug
Explanation: Efficacy is the measure of the maximum biological response that a drug can produce, often described as its intrinsic activity (or $\text{Emax}$). It indicates the drug’s ability to activate a receptor and produce a cellular effect.
8. For computing kinetic parameters the concentration versus time data is plotted on;
A. Ordinary graph paper
B. Plane paper
C. Semi log graph paper
D. Log graph paper
Correct Answer: (C) Semi log graph paper
Explanation: In pharmacokinetics, when determining parameters like the elimination half-life ($\text{t}1/2$), plasma concentration-time data is typically plotted on semi-log graph paper (log scale for concentration, linear scale for time) to linearize the first-order elimination phase.
9. The discipline of pharmacology dealing with mode of action of drug is known as;
A. Pharmacotherapy
B. Pharmacy
C. Pharmacodynamics
D. Phamacognosy
Correct Answer: (C) Pharmacodynamics
Explanation: Pharmacodynamics is the study of the biochemical and physiological effects of drugs on the body, including the drug’s mechanism or mode of action (what the drug does to the body).
10. Pharmacy deals with;
A. Mechanism of action of drug
B. Preparation of drug
C. Identification of drug
D. Metabolism of drug
Correct Answer: (B) Preparation of drug
Explanation: Pharmacy is the health profession concerned with the art and science of preparing, compounding, dispensing, and reviewing medications, ensuring their safe and effective use.
11. Subscription carries;
A. Instruction for pharmacist
B. Instruction for the user
C. Instruction for the prescriber
D. Instruction for the doctor
Correct Answer: (A) Instruction for pharmacist
Explanation: In a prescription, the Subscription is the section containing directions for the pharmacist regarding the type of dosage form and the amount to be dispensed (e.g., “Dispense 30 tablets”).
12. Soporifics are;
A. Pain killer
B. Sleep inducing agents
C. Antipyretics
D. Anesthetics
Correct Answer: (B) Sleep inducing agents
Explanation: Soporifics is an older term for drugs that induce or sustain sleep; they are generally synonymous with hypnotics or sleep-inducing agents.
13. Intrathecal administration of drug means;
A. Epidural administration
B. Administration into C.S.F.
C. Intraoccular
D. Intracranial
Correct Answer: (B) Administration into C.S.F.
Explanation: Intrathecal administration involves injecting a drug directly into the subarachnoid space of the spinal cord, allowing it to enter the cerebrospinal fluid (C.S.F.).
14. In epidural administration drug is administered;
A. into C.S.F.
B. Above the dura mater
C. Below the dura mater
D. Into the dura mater
Correct Answer: (B) Above the dura mater
Explanation: Epidural administration involves injecting the drug into the space immediately Above the dura mater (the outermost meningeal layer), but outside the subarachnoid space and the C.S.F.
15. Derivatives of sulfanilamides are called;
A. Barbiturates
B. Sulfonic acid
C. Sulfonamide
D. Sulfadiazine
Correct Answer: (C) Sulfonamide
Explanation: The chemical class of antimicrobials derived from the base structure of sulfanilamide are collectively known as sulfonamides.
16. Metabolite of drug may become;
A. More lipophilic
B. More polar than parent drug
C. Non polar than parent drug
D. All of the above
Correct Answer: (B) More polar than parent drug
Explanation: The primary goal of drug metabolism (biotransformation) is to convert lipophilic (non-polar) drugs into metabolites that are More polar than the parent drug, making them easier to excrete.
17. Biotransformation of drug facilitates excretion of drug;
A. By changing it to more active
B. By converting non polar drug to polar
C. By converting polar drug to non polar
D. None of the above
Correct Answer: (B) By converting non polar drug to polar
Explanation: Biotransformation facilitates renal excretion by making the drug more water-soluble (i.e., converting non-polar drug to polar) so it cannot be easily reabsorbed across the renal tubules.
18. Polar substances are excreted;
A. Easily by kidney
B. Slowly by kidney
C. Normally by kidney
D. Rapidly by the Kidney
Correct Answer: (D) Rapidly by the Kidney
Explanation: Because the renal tubules cannot efficiently reabsorb water-soluble (Polar) compounds, they are retained in the filtrate and are therefore Rapidly by the Kidney.
19. 1st pass effect;
A. Increase the bioavailability of the drugs
B. Decrease the bioavailability of the drugs
C. Increase the excretion of drugs
D. Decrease the excretion of drugs
Correct Answer: (B) Decrease the bioavailability of the drugs
Explanation: The First-Pass Effect (or pre-systemic metabolism) is the rapid hepatic metabolism of a drug before it reaches the systemic circulation, thus Decrease the bioavailability of the drugs.
20. Drug administered I/V may excrete in faeces due to;
A. Absorption of drug
B. Metabolism of drug
C. Due to entero-hepatic circulation
D. All of the above
Correct Answer: (C) Due to entero-hepatic circulation
Explanation: A drug administered intravenously (I/V) is entirely systemic. If it appears in the feces, it must have undergone plasma-to-bile transfer, followed by excretion into the intestine, a process known as entero-hepatic circulation.
21. Biliary excretion drug refers to excretion;
A. In urine
B. In milk
C. In faeces
D. In sweat
Correct Answer: (C) In faeces
Explanation: Biliary excretion is the elimination of drugs or metabolites via the bile, which is released into the small intestine and subsequently excreted In faeces.
22. Tick the true statement;
A. All the antibacterials are antibiotics
B. All the antibiotics are antibacterial
C. All the antibacterial are obtained from living organism
D. All the antibiotics prepared in laboratory
Correct Answer: (B) All the antibiotics are antibacterial
Explanation: By definition, an antibiotic is a substance that inhibits or kills microorganisms (including bacteria). Therefore, all antibiotics inherently possess antibacterial activity, even if some are now synthesized chemically.
23. All the antibiotics are;
A. Bactericidal only
B. Bacteriostatic only
C. Bacteriosatatic and bactericidal
D. None of the above
Correct Answer: (C) Bacteriostatic and bactericidal
Explanation: Antibiotics have varied mechanisms. Some are bactericidal (kill bacteria), and others are bacteriostatic (inhibit growth), meaning the general class includes both types.
24. Drugs give their action;
A. Due to their specific receptor only
B. Due to non receptor mediated mechanism only
C. Due 1 and 2
D. Due to metabolism of drug
Correct Answer: (C) Due to 1 and 2
Explanation: The majority of drugs act via a specific receptor (1), but many others act through non-receptor mediated mechanisms (2), such as chelating agents, antacids, or osmotic diuretics.
25. In anaphylactic shock due to drug;
A. Blood pressure is increased to high limit
B. Blood pressure dropped to critical level
C. Nothing happen to blood pressure
D. None of the above
Correct Answer: (B) Blood pressure dropped to critical level
Explanation: Anaphylactic shock is a severe, systemic hypersensitivity reaction involving massive histamine release, leading to widespread vasodilation and increased capillary permeability. This results in a sharp, dangerous drop in blood volume and Blood pressure dropped to critical level (hypotension).