Top 20 General Pharmacology Questions Every Student Should Know – Doctors-Online

Top 20 General Pharmacology Questions Every Student Should Know

Q.1  What is Pharmacology?

Ans: Pharmacology is a branch of science that deals with the interaction of drugs with living organisms. Or The study of Pharmacokinetics and Pharmacodynamics.

Q.2 What is a Drug?

Ans: A drug is any chemical entity that causes a change in biological function in a living organism.some drugs are formed inside the body such as insulin and noradrenaline etc.drugs that are introduced into the body from outside are called Xenobiotics.

Q.3 What Is a Dose?

Ans: A Specific Amount of Drug Prescribed to be taken at one time.

Q.4 What Is Blood Brain Barrier?

It is A Tight Endothelial Cells Of the Brain Capillaries And Glial Cells Of The Brain Around The blood capillaries that doesn’t allow the passage of certain lipid insoluble substances to pass from the blood into the brain.Lipid Soluble Drugs can easily Cross This Barrier.Examples Of Lipid soluble Drugs are; Diazepam, Thiopental, And Phenobarbitol.

Q.5 What is Volume Of Distribution?

Ans: The total Volume Of The Body Fluid in which a drug appears to be distributed according to its concentration in the blood or plasma.VD of a drug can be determined by the following Formula,

VD (Volume OF Distribution) =Total Amount OF Drug In the Body/Concentration of drug in the blood plasma.

Q.6 What Is Potency?

Ans: It is the weight of the drug that produces a certain magnitude of response.For Example Lesser the weight of drug required to produce a given effect, more its potency.Also More the weight of the drug required to produce the same effect lesser its potency.e.g Clonidine Produce its antihypertensive effect in 0.2-0.3mg Daily Dose.While Antihypertensive dose of methyldopa is 500-2000mg Per Day.Thus Clonidine IS more Potent than methyldopa.

Q.7 What Is Efficacy?

Ans:If the dose of a drug is increased its effect will be increased proportionately, until a stage is reached beyond there is no further increase in effect will occur,even if a large dose of drug is given.thix maximum effect of drug beyond which no further increase in its effect occurs even if the dose of the drug is increased to a large amount is called efficacy or maximal efficacy.example morphine has more efficacy than aspirin as an analgesic .morphine is more effective in the severe type of pains while aspirin is effective in mild to moderate pain.

Q.8 What is Therapeutic index?

The ratio between median toxic dose (TD50) and median effective dose (ED50) is called therapeutic index.

Therapeutic index= TD50/ED50

Q.9 What is idiosyncrasy?

It is a rare type of response to a drug that is not related to its dose, that is, even a small dose can cause it.For example.A rare adverse effect with chloramphenicol is aplastic anemia.

Q.10 What is Hypersensitivity?

An allergic or immunological response to a drug .for example anaphylactic shock with penicillin is a severe type of hypersensitivity reaction.


Q.11 What is Tolerance?

Ans: Repeated use of a drug causes a gradual decrease in the response to the drug.e.g chronic use of morphine will decrease many of its effects in the body, therefore the dose of the drug has to be increased with the passage of time to maintain the usual effects of the drug.

Q.12 What is a Receptor?

Ans: Receptor is a macromolecule (Big molecule).Most of the receptors are protein in nature.mostly those drugs that act on the cells bind to the receptors.Those drugs which bind to the receptor and show their effect are called agonists.While some drugs bind to the receptor but don’t produce an effect.These drugs are known as an antagonist as they prevent the binding of agonists with the receptors.

Q.14 What is the adverse drug reaction?

Drugs may produce two types of effect i.e Useful effects and harmful effects.harmful effects are also known as adverse drug reaction or undesired effects.These effects may range from the mild type of adverse effect to severe effects that may cause a death of the person.

Adverse drug reaction may be classified into the following types;


Drug allergy

Direct toxic effect

Drug dependence


Q.15 What is Shock?

It is a clinical condition in which there is an inadequate supply of blood to tissues.it causes hypotension, oliguria, and metabolic acidosis.Following are the common types of shock:

A. Hypovolemic shock

B. Septic shock

C. Cardiogenic shock

D. Anaphylactic shock

Q.16 What is Drug Clearance?

Ans: It Can be defined as Volume Of blood or plasma cleared of the drug in a unit period of time.Thus, to determine clearance we have to find that volume of blood or plasma from which a drug is removed during a unit period of time.By removal of drug we mean metabolism and excretion of drug.if we know the clearance of a drug we can adjust its dose properly.clearance of the drug can be determined by the following formula.

Cl: Rate of elimination/Concentration of drug in the blood

Where is Cl is clearance?

Q.17 What is Drug Excretion?

Ans: Removal of drugs from the body is known as their excretion.Drugs are excreted from the body either in the form of their metabolites or in unchanged form.Excretion can occur from the following routes;

A) Faecal

B) Renal

C) Biliary


E)Others like to sweat, saliva, milk etc

Q.18 What is Toxicology?

It is an aspect of pharmacology that deals with the adverse effects of drugs on living organisms .in addition to drugs used in therapy, it also deals with many other chemicals that may be responsible for the household, environmental, or industrial intoxication.

Q.19 What is antidote?

Ans: Antidotes are Any Substance which Is Used To oppose the effects of poisons without causing any damage to The body. Example antidote for benzodiazepine is flumazenil.

Q.20 What is Bioavailability?

It can be defined as a fraction of unmodified drug reaching into the systemic circulation after it is administered by any route.IV administration of drug produces 100% bioavailability as a whole of the drug enters the systemic circulation.Oral administration of the drug may not produce 100% bioavailability due to incomplete absorption of a drug from the Gastrointestinal tract and due to first pass effects of some of the drugs.


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