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DrX Whiz Niraj
Welcome to DrX Whiz Niraj. In pharmaceutical exams, 2-mark definition questions hold significant importance. In this post, we have compiled all the Very Important Definitions from Unit 1 to Unit 5 of Pharmacology I, written exactly how you should write them in your university exams to score full marks.
Unit 1: General Pharmacology - I
Pharmacology
The science that deals with the study of drugs, their properties, actions, mechanism of action, therapeutic uses, and adverse effects on living systems.
Pharmacokinetics
It is the study of the absorption, distribution, metabolism, and excretion (ADME) of drugs. Simply put, it is "what the body does to the drug".
Bioavailability
It is defined as the rate and extent (percentage) of an administered drug that reaches the systemic circulation in an unchanged, active form.
First-Pass Metabolism
The pre-systemic metabolism of a drug in the liver or gut wall before it reaches the systemic blood circulation, significantly reducing its bioavailability.
Biological Half-Life (t½)
The time required for the concentration of a drug in the blood plasma to reduce to exactly half (50%) of its original value.
Apparent Volume of Distribution (Vd)
A hypothetical volume of fluid into which the total dose of a drug administered would have to be uniformly distributed to produce the observed blood plasma concentration.
Unit 2: General Pharmacology - II
Pharmacodynamics
The study of the biochemical and physiological effects of drugs and their mechanisms of action. Simply put, it is "what the drug does to the body".
Receptor
A specialized protein macromolecule present on the cell surface or intracellularly, which binds to a specific drug/ligand to produce a biological response.
Agonist & Antagonist
Agonist: A drug that binds to a receptor and produces a biological response.
Antagonist: A drug that binds to a receptor but produces no response; it blocks the action of an agonist.
Therapeutic Index (TI)
It is the ratio of the toxic dose (TD50) to the effective dose (ED50). It acts as an indicator of the safety margin of a drug. Higher TI = Safer drug.
Adverse Drug Reaction (ADR)
Any noxious, unintended, or undesirable effect of a drug that occurs at doses normally used in humans for prophylaxis, diagnosis, or therapy.
Pharmacovigilance
The science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.
Unit 3: Drugs Acting on PNS
Neurohumoral Transmission
The process of transmission of nerve impulses across synapses and neuroeffector junctions by the release of chemical messengers called neurotransmitters.
Sympathomimetics
Drugs that mimic the actions of the sympathetic nervous system by stimulating adrenergic receptors (e.g., Adrenaline, Salbutamol).
Parasympatholytics
Drugs that block or inhibit the actions of the parasympathetic nervous system by antagonizing muscarinic receptors (e.g., Atropine).
Local Anesthetics
Drugs that cause reversible loss of sensation in a specific, localized area of the body by blocking nerve conduction (blocking Na+ channels) without causing loss of consciousness.
Glaucoma
A group of eye conditions that damage the optic nerve, primarily associated with abnormally high intraocular pressure (IOP), which can lead to blindness.
Unit 4: Drugs Acting on CNS - I
General Anesthetics
Drugs that produce a reversible loss of consciousness, pain sensation, and reflexes, allowing major surgical procedures to be performed.
Sedatives & Hypnotics
Sedatives: Drugs that reduce anxiety, excitement, and calm the patient without inducing sleep.
Hypnotics: Drugs that depress the CNS to induce and maintain sleep resembling natural sleep.
Epilepsy
A chronic neurological disorder characterized by recurrent, unprovoked seizures caused by excessive, abnormal electrical discharges in the brain.
Neurotransmitters
Endogenous chemical messengers synthesized by neurons that transmit signals across a chemical synapse from one neuron to another target neuron, muscle, or gland.
Unit 5: Drugs Acting on CNS - II
Parkinson’s Disease
A progressive neurodegenerative disorder caused by the degeneration of dopaminergic neurons in the substantia nigra, leading to tremors, rigidity, and bradykinesia.
Alzheimer’s Disease
A progressive neurodegenerative disease associated with the loss of cholinergic neurons and beta-amyloid plaque formation, leading to severe memory loss and cognitive decline.
Drug Addiction
A chronic, relapsing disorder characterized by compulsive drug seeking and use despite harmful consequences.
Drug Tolerance
A pharmacological concept where a decreased response to a drug occurs after repeated administration, requiring a higher dose to achieve the original effect.
Drug Dependence
A state in which the body (Physical) or mind (Psychological) has adapted to the presence of a drug, and sudden withdrawal causes severe withdrawal symptoms or intense cravings.
Nootropics
Also known as "cognitive enhancers" or "smart drugs." These are drugs that improve memory, learning, and overall cognitive functions (e.g., Piracetam).
Frequently Asked 2 Marks Questions in University Exams
- Define Bioavailability and mention the factors affecting it.
- What is the difference between Pharmacokinetics and Pharmacodynamics?
- Define Therapeutic Index and write its formula.
- Define Pharmacovigilance.
- What is the difference between an Agonist and an Antagonist?
- Define First-Pass Metabolism. Why is it significant?
- Differentiate between Sedatives and Hypnotics.
- Define Drug Tolerance and Drug Dependence.
- What are Nootropics? Give one example.
- Define Local Anesthetics and General Anesthetics.
Note: By memorizing the definitions provided in the cards above, you can easily secure full marks in the 2-mark section of your question paper!