What is medicine?1-1 Definition of DrugsSubstances that enter in vivo and have biological effectsex) Caffeine, nicotine, alcohol can also be a medicineIt should be borne in mind that there are differences in effects for each substance.It can be poisonous when used at high doses for a long time.1-2 Good DrugDrugs exhibiting desired activity and free from toxicity and side effectsSince drugs have ..

Drug receptors are protein or molecular targets where drugs bind to produce effects in the body. These receptors are generally classified into four main types: 1. Ion Channel-linked Receptors These receptors are connected to ion channels, and when a drug binds, the ion channel opens or closes, regulating the flow of ions into and out of cells. This rapid response plays an essential role in nerve..

The dose or concentration-response curve (DRC or CRC) of a drug indicates the response with variable dose. Pharmacodynamic principles measuring efficacy and potency can be quantified using dose-response curves. In general, gradual dose-response relationships of the drug reflects the number of receptors that are effectively occupied. DRC generally showed between response and log dose of a drug ov..

Research evidence suggested the most of the drugs show specific action through the specific receptor. Receptors are macromolecule, which presents at the cell surface inside the cell and each receptor has a structural specific binding site like a lock for the ligand and the 3D structure of the specific drug molecule (ligand) acts as the key; means stereo-structural specific ligand (drug)-receptor..

The receptor is a macromolecule (mostly protein in nature and some are nucleic acids) having a specific ligand/drug binding site, located at the surface or inside the cells that serve to recognize the signals of ligands and initiate the response, but itself has no other function.LigandsThe molecules having the affinity for the receptor and may alter the ongoing function. Ligands are generally ca..