Introduction, Sources of Drugs and Routes of Drug Administration

Essential vocabulary terms, definitions, subfields, routes of administration, and drug delivery concepts from Chapter 1 of General Pharmacology.

Pharmacology

The science that deals with the study of drugs and their interaction with living systems, derived from Greek pharmacon (meaning drug) and logos (meaning study).

Drug (WHO definition)

Any substance or product that is used or intended to be used to modify or explore physiological systems or pathological states for the benefit of the recipient.

Pharmacodynamics

The study of the effects of drugs on the body and their mechanisms of action (what the drug does to the body).

Pharmacokinetics

The study of the absorption, distribution, metabolism, and excretion of drugs (what the body does to the drug).

Therapeutics

The branch of pharmacology that deals with the use of drugs in the prevention and treatment of disease.

Pharmacogenetics and Pharmacogenomics

The study of genetically mediated variations in response to drugs.

Pharmacovigilance

The science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.

Toxicology

The study dealing with the adverse effects of drugs and poisons, including the detection, prevention, and treatment of poisonings.

Chemotherapy

The use of chemicals for the treatment of infections and chemical compounds to treat malignancies.

Pharmacy

The science of identification, compounding, and dispensing of drugs, including collection, isolation, purification, synthesis, and standardization of medicinal substances.

Prescription drugs

Drugs that can be sold only on producing a doctor's prescription, classified as Schedule H drugs as per the Drugs and Cosmetics Act of India.

Gene therapy

The replacement of a defective gene by insertion of a normal, functional gene, or providing extra copies of a normal gene.

Enteric Coated Tablets

Tablets coated with cellulose-acetate, phthalate, or gluten that resist gastric acid digestion and disintegrate in the alkaline intestinal juices.

Evacuant Enema

The rectal administration of liquid (approximately $600\text{ mL}$ of soap water) to distend, lubricate, and empty the bowel.

Retention Enema

The rectal administration of a fluid solution (approximately $100\text{ mL}$) retained in the rectum for local action.

Hypodermoclysis

The subcutaneous administration of large volumes of saline, utilized in pediatric practice.

Dermojet

A needleless transdermal or subcutaneous drug delivery system that projects a high-velocity jet of solution from a fine orifice using a gun.

Sublingual Route

Administration route where a drug tablet or pellet is placed under the tongue to dissolve and absorb across the sublingual mucosa directly into circulation.

Inunction

A route of administration where a drug is rubbed into the skin to get absorbed for systemic effects.

Prodrug

An inactive form of a drug that gets metabolized into its active derivative inside the body.

Ocusert

A thin elliptical drug delivery unit placed under the eyelid that slowly releases drug through a membrane by diffusion at a steady rate.

Osmotic Pump (GITS)

A tablet-shaped delivery unit coated with a semipermeable membrane and laser-drilled hole that uses swelling of an osmotic layer to push drug out at a constant rate.

Liposomes

Phospholipids suspended in aqueous vehicles to form minute vesicles that encapsulate drugs for site-specific delivery.

Prescription

A written order by a physician to a pharmacist to prepare and/or dispense specific medication for a specific patient.