Importance of Pharmacology

Pharmacology word derived from the Greek words, "pharmakos" meaning medication or drug, and "logos" meaning research. It is defined as the study of drugs, including their origin, history, uses, and properties.

Overview

• The study of drug action on a biological system denotes the term pharmacology. It combines elements of medicine and biology and their interactions. Pharmacology is not the same as medicine. It is concerned with the discovery and characterization of substances that impact the human body. This study includes the origin, properties, and impact of drugs on living systems, such as organic, chemical, and therapeutic effects. Drugs are any material such as natural, artificial, or endogenous molecules, which influence any part of the body. It is primarily concerned with the impact of drugs on the human body. A drug is a medication that helps treat several illnesses and also improves physical or mental health.
• Terminology ----------
  Pharmacodynamics-It is a branch of pharmacology that studies the body's reactions to a drug.
  Pharmacokinetics-It studies the movement of the drug within the body.
  Pharmacy- Pharmacy is the science and art of drug preparation and standardization.
  Pharmacognosy This study involves analyzing the crude drugs derived from plants, animals, minerals, and their constituents.
  Toxicology- Toxicology is studying the adverse effects of any biotic or synthetic agents on humans and the environment.
  Pharmacotherapeutics- Pharmacotherapeutics is the study of the uses and effects of therapeutic drugs.
  Drug- A drug is a substance when ingested into the body, causes any metabolic effects.
  Pharmacopeia- A pharmacopeia is an official book that lists and explains all types of drugs that help treat patients.
  Antibiotics- Antibiotics are drugs used for treating bacterial infections, and do not show any effect on viruses.
  Chemotherapy- Chemotherapy is a treatment that uses chemicals drugs to destroy the body cells that proliferate rapidly.

• Pharmacokinetics----------
  The study of the kinetics of absorption of drugs, their dispersion, biotransformation, and elimination is known as pharmacokinetics. There are two ways for the drugs to enter the body, namely the enteral and the parenteral route.
  
  The enteral route involves drug intake by the mouth and enters the body through the gastrointestinal tract.
  
  Parenteral is another route where the drug is infused through veins or arteries.
  
  Adsorption is the process in which a drug enters into the blood circulation. It travels by various transports such as active, passive, pinocytosis, and facilitated diffusion at a cellular level.
  
  Distribution is the dispersion of substances in the body fluids and tissues. Factors influencing distribution include tissue permeability, blood flow, and blood pH.
  
  The storage of drugs occurs in various sites such as adipose tissues, bones, muscles, and organs.
  
  Metabolism, a process of biotransformation in which a drug undergoes many chemical changes resulting in a metabolite with a new compound, includes changes in its activities.
  
  Excretion or elimination is a process of removal of drugs from the body.
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Pharmaodynamics---------

Pharmacodynamics is the study of the reaction of the body towards the drug, which involves two mechanisms of drug actions, namely receptor-mediated and non-receptor mediated mechanisms.

A receptor is a macromolecular component, which has specific sites for the binding of drugs and neurotransmitters, which on binding to the drug, initiates its effects.

There are various types of receptors, such as enzyme-linked receptors, insulin receptors, and nuclear receptors.

Non-receptor-mediated interactions target enzymes, ion transporters, ion channels, DNA, and microtubules directly.

Mechanism of actions of drugs has both beneficial and harmful effects, which includes side effects, allergies, cytotoxic effects on organs, and effects due to drug-drug interactions and drug-food interactions.

Terminologies involved in Pharmacodynamics ----------

• Agonist- A substance or a drug which can bind and activate a receptor in order to produce a biological or pharmacological response.
• Antagonist- An antagonist is a drug, which when bound to the receptor, altogether stops or prevents the receptor from producing a response.
• Potency- Clinical efficacy determines the therapeutic potency of drugs in humans, while potency expresses the action in terms of the concentration or volume of the dosage needed to achieve a specified impact.
• Efficacy (EMax)- Efficacy is the maximum response that a drug can achieve.
• Affinity- Affinity is the ability of a drug to bind to receptors.
  ED50- ED50 is the dose of a drug, which produces a specific targeted effect in 50% of the population that has taken it
• Therapeutic index (TI)- The therapeutic index is a drug safety measurement.
• Therapeutic window (TW) -A therapeutic window is a spectrum of doses that induces a therapeutic response in patients without causing any side effects.