Pharmacology ( introduction)

Pharmacology 

➔Pharmacology is a branch of medicine and pharmaceutical sciences which is concerned with the study  of drug or medication action, where a drug can be broadly or narrowly defined as any man-made, natural, or endogenous (from within the body) molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism.

➔ More specifically, it is the study of the interactions t that occur between a living organism and chemicals that affect normal or abnormal biochemical function. 

➔ If substances have medicinal properties, they are considered pharmaceuticals.

➔ The field encompasses drug composition and properties, synthesis and drug design, molecular and cellular mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, interactions, chemical biology, therapy, and medical applications and antipathogenic capabilities.

➔ The two main areas of pharmacology are pharmacodynamics and pharmacokinetics.

➔ Pharmacodynamics studies the effects of a drug on biological systems.  

➔ pharmacodynamics discusses the chemicals with biological receptors.

➔ pharmacokinetics studies the effects of biological systems on a drug. 

➔ pharmacokinetics discusses the absorption, distribution, metabolism, and excretion (ADME) of chemicals from the  biological systems.

➔ A number of phases occur once the drug enters into contact with the organism, these are described using the acronym LADME:

● Liberation of the active substance from the delivery system,

● Absorption of the active substance by the organism,

● Distribution through the blood plasma and different body tissues,

● Metabolism that is inactivation of the xenobiotic substance, and finally

● Excretion or elimination of the substance or the products of its metabolism.

➔ Liberation –the process of release of a drug from the pharmaceutical formulation.

➔ Absorption – the process of a substance entering the blood circulation.

➔ Distribution – the dispersion or dissemination of substances throughout the fluids and tissues of the body. 

➔ Metabolism (or biotransformation, or inactivation) – the recognition by the organism that a foreign substance is present and the irreversible transformation of parent compounds into daughter metabolites.

➔ Excretion – the removal of the substances from the body. In rare cases, some drugs irreversibly accumulate in body tissue.

➔ The two phases of metabolism and excretion can also be grouped together under the title elimination.

➔ In particular, pharmacodynamics is the study of how a drug affects an organism, whereas pharmacokinetics is the study of how the organism affects the drug. 

➔ Both together influence dosing, benefit, and adverse effects. 

➔ Pharmacodynamics is sometimes abbreviated as PD and pharmacokinetics as PK, especially in combined reference (for example, when speaking of PK/PD models).

Reference

➔ Wikipedia

➔ Google images

By :- pinak Bamaniya