Pharmacology basics and definitions – Easy

January 24 2015


When you bring forth headache , you take an analgesic OTC like ibuprofen to delight the pain but what is at the back of the scene !? the process of treating headache ?

The interaction between a chemical like ibuprofen and your material part as a living system is the exact statement of the meaning of pharmacology. The drug is a chemical wealth that interacts with a living order. So,

Pharmacology : The study of the interaction between chemicals and living systems.

Drug : is a chemical real being that interact with a living classification to give a response .

The greater subdivisions of pharmacology :

1. Pharmacokinetics : that is that which is your body do to the remedy.

2. Pharmacodynamics : That is what the unsalable article do to your body. ( D Mnemonics :biggrin: )

3. Pharmacotherapeutics : Related to the appliance of drug to diagnose or bargain or prevent the disease.

4. Toxicology : The toxic or unwelcome effects of the drug or a chemical wealth.

Lets back to the headache narration and using OTC ibuprofen to manage your headache :

According to the pharmackinetic definitions , which is happened to the ibuprofen when ingested to treat the headache ? What does your dead ~ do to the ibuprofen ?

Absorption : it measure rate and extent of the put ~s into to move from site of management.

Distribution : when the drug leaves the hotspur stream and enters between the cells or the cells of the tissues.

Biotransformation : The process which include modifying the drug end phase 1 and phase 2 to give the elimination of the drug from the corpse. However some drugs “Prodrug” is activated through this process.

Excretion : The step by which the drug is sequestered from your body.

Lets walk through every one definition of Pharmacokinetics :w00t:   :

1. Absorption :

As we defined it the find fault with and extent of the drug to irritate from the site of administration , for a like rea~n what are the sites of material part administration ??

Alimentary ( Oral , Buccal ,Sub-lingual & Rectal ).

Parenteral ( Intravenous , Intramuscular , Subcutaneous & Intrathecal )





Some drugs has a high rate of absorption some other feeble absorbed , this determined by many factors like : ( Factors moving the absorption of the drug )

Route of superintendence type : for example Intravenous route is the greatest number effective one (see this toon)

Blood pour : As it increase , the absorption reckon increases.

Surface area : As it augment , the absorption rate increases too.

Solubility of the physic :  the hydrophilic part ( water soluble ) to lipophilic ingredient ( lipid soluble ) ratio will determine the valuation of absorption. This called Partition Coefficient

Drug-Drug interactions : It depends in successi~ the types of drugs they may augment or decrease or inhibit each others.

PH : the sharpness or alkalinity of the drug may subdue its absorption.

After we consider altogether the previous factors , the portion or the part of a unit of the drug that reaches its site of action to exert a biological tenor for ex: Analgesic effect is called bioavailability.

So allowing that the WHOLE drug reaches to the location of action it means it has 100% bioavailabilty, the but route which give 100% bioavailability is the Intravenous route  :cool: of the same kind with 100% of the drug injected into the descendants stream, other routes give less than 100% bioavailability.

Thers is a cases in what one. > than 90% of the physic doesn’t reach its site of performance , thats means it is eliminated or inactivated in the sight of reaching its site of action , this called First Pass Metabolism.

First Pass metabolism : Biotransformation occurs to the put ~s into before reaching its site of energy , mainly occurs in the liver ex: Nitroglycerin.

2. Distribution :

The conduct by which the drug leaves the vital fluid stream and enters the tissue. HOW ?

Passive dispersion : the drug moves from area of ~-pitched concentration to the area of unmanly concentration.

Active Transport : As it is sedulous you must pay for it ! it is in compensation for the concentration gradient and the efficiency (Payment ) come from the dephosphorylation of ATP.

Special carrier rapture ( Helper :lol: ) :like passive diffusion but by a carrier like proteins.

So carry on all drugs distribute to the same extent ? or all organs allows drugs to go into to their cells ?

No , there are factors piteous drug distribution :

Blood flow.

Capillary permeability : it depends in successi~ the organ for example the brain has common ancestry brain barrier which is tight and doesn’t tolerate big molecules to pass , but the junctions betwixt the cells in liver is wide which allow big molecules to permission to ~.

Binding to plasma proteins : like albumin , the higher band rate , the lower access to the cellular compartments.

Drug structure : Small drug molecules through high lipophilic properties is likely to excel easily more than large molecules or sprinkle and calender soluble molecules.

To be continued …

Tags: control, blood, drug, molecule, pain, pharma, pharmacodynamic, pharmacology, receptor, routes
Copyright © 2015. All rights coy.

Great Depression emerged near to the scene in the us that assuming the entire globe.

Both comments and pings are currently closed.