The study of drugs and their effects on the body is known as pharmacology.
Pharmacodynamics is the study of drug action mechanisms…how a drug affects our bodies.
Most drugs elicit a response based on how they interact with a specific protein, which occurs via a receptor protein embedded in the cell membrane or inside the cell within the cytoplasm or nucleus.
A drug can sometimes act as a ligand for a receptor.
A drug could be:
Agonist: mimics the native ligand and induces the typical physiological response (also known as a facilitator) – Agonist promotes normal protein function.
Antagonist: binds to the active site but does not activate the receptor (also known as a blocker or inhibitor) – An antagonist silences the protein and prevents it from functioning.
Drug potency is the strength of a drug at a specific dosage or the amount of a prescription needed to produce a particular effect. Potency can also be defined as a drug’s affinity for a receptor (high affinity = small amount of medication required).
Drug Efficacy: the maximum effect that a drug can achieve. Efficacy is also defined as the drug’s effect on the receptor and how well it acts as an agonist or antagonist.
Absorption is the process by which a drug moves from the administration site into the bloodstream.
Traveling through the bloodstream to reach target cells and molecules
Metabolism: the process by which enzymes modify a drug to render it ineffective.
Excretion: the removal of a drug from the body through urine or feces.