General Pharmacology Vocabulary Flashcards

A set of 20 vocabulary flashcards defining core terms in pharmacokinetics, pharmacodynamics, drug administration, kinetics, clinical trials, and toxicological outcomes.

pK Value

The pH of a medium at which a drug is 50% ionised and 50% non-ionized, measured using the Henderson-Hasselbalch equation.

P-glycoprotein

An active transporter (ATP-binding cassette protein) that acts as an efflux transporter to reduce drug absorption in the GIT and increase drug excretion in the kidneys, liver, and blood-brain barrier.

First Pass Effect

The pre-systemic metabolism and degradation of an orally administered drug in the liver before it reaches the systemic circulation through the inferior vena cava.

Bioavailability

The fraction of a drug that reaches the systemic circulation in unchanged form over time, calculated as $F = \frac{\text{AUC}_{\text{oral}}}{\text{AUC}_{\text{IV}}}$.

Volume of Distribution

The apparent or false volume of plasma required to contain a drug in equal concentration to that of plasma, reflecting the extravascular movement of the drug into organs.

Redistribution

The mechanism terminating the clinical action of highly lipid-soluble drugs (such as Thiopentone and Fentanyl) by movement from blood and organs into fats rather than by urinary elimination.

Phase 1 Reaction

A catabolic reaction (such as oxidation or reduction) occurring inside smooth endoplasmic reticulum microsomes that converts a drug into an active or inactive metabolite.

Phase 2 Reaction

An anabolic or conjugation reaction (such as glucuronide conjugation) occurring outside the smooth endoplasmic reticulum that links a polar group to a drug to render it water-soluble and inactive.

Hit and Run Drugs

Suicide inhibitor drugs that irreversibly attach to target organs or enzymes and continue to exert action even after their complete elimination from blood plasma.

Zero Order Kinetics

A process of drug elimination in which a constant amount of drug is cleared per unit time, resulting in a low clearance capacity and a half-life directly proportional to plasma concentration.

First Order Kinetics

A process of drug elimination where the rate of drug removal is directly proportional to plasma concentration, maintaining a constant clearance capacity and a constant half-life.

Plateau Concentration

The steady state concentration ($C_{\text{ss}}$) achieved in 4 to 5 half-lives when a drug is administered at a constant rate equal to its rate of elimination.

Competitive Antagonist

A pharmacological blocker that competes for the exact same receptor site as an agonist, producing a rightward shift in the dose-response curve with an unchanged $V_{\text{max}}$ and an increased $K_m$.

Non-Competitive Antagonist

A pharmacological blocker that binds to an allosteric site on a receptor, producing a downward shift in the dose-response curve with a reduced $V_{\text{max}}$ and an unchanged $K_m$.

Therapeutic Index

The margin of safety of a drug expressed as the ratio between toxic dose and effective dose, calculated as $\text{TI} = \frac{\text{TD}_{50}}{\text{ED}_{50}}$.

Phase 0 Clinical Trial

A non-mandatory, unblinded micro-dosing trial in 2 to 5 healthy human volunteers using a 100-microgram radiolabeled drug dose to check target binding.

Orphan Drugs

Medications developed specifically to treat rare diseases that have a prevalence of less than 1 per 5 lakh (500,000) population.

Ebstein Anomaly

A congenital cardiac malformation involving an abnormal tricuspid valve and an enlarged right atrium caused by maternal Lithium administration during pregnancy.

Phocomelia

A severe teratogenic malformation characterized by shortened or missing limbs, classic to fetal exposure to Thalidomide.

Pharmacovigilance

The specialized branch of pharmacology responsible for monitoring, evaluating, and reporting adverse drug reactions to regulatory authorities.