Basic concepts of Pharmacology

BASICS OF PHARMACOLOGY

Description also available in video format (attached below)

Introduction

1) Pharmacology is a science of drugs that deals with the study of drugs or medicines effects on the body.

2) The term Pharmacology derives from two Greek words

• Pharmakon (Drug or Medicine)
• Logos (Science)

DRUGS (Medicines)

Definition

Drug is a chemical substance that is used to modify the physiological system for the benefit of the recipient (patient).

Sources of drugs

The drugs are obtained from various sources such as

• Minerals (Paraffin, Magnesium sulfate)
• Animals (Insulin, Thyroid)
• Plants (Morphine, Quinine)
• Synthetic (Aspirin, Sulfonamides)
• Microbes (Penicillin & other antibiotics)
• Genetical engineering (Human insulin, Hormones)

Dosage forms of drug

The drugs are available in various dosage forms such as

• Tablets
• Capsules
• Injection
• Infusion
• Solution
• Cream
• Suspension
• Aerosol etc

Routes of drug administration

The drugs can be administered from various routes such as

• Oral (PCM tablet)
• Sublingual (Nitroglycerine tablet)
• Rectal (Dulcolax suppositories)
• Intravenous (Vancomycin Inj)
• Intramuscular (Testosterone Inj)
• Subcutaneous (Insulin Inj)
• Inhalational (Nitrous oxide)
• Intravaginal (Estrogen)

Branches of Pharmacology

Mainly there are two branches of Pharmacology that deals with the drug study-

• Pharmacokinetics
• Pharmacodynamics

1) Pharmacokinetics

It can be defined as the study of "what the body does with the drug" and covers the following aspects-

• Absorption (moving of drug in blood stream)
• Distribution (moving of drug to various organs)
• Metabolism (breakdown of drug)
• Excretion (removal of drug from the body)

2) Pharmacodynamics

It can be defined as the study of "what the drug does with the body" and covers the following aspects-

• Drug action (interaction of drug with the body cells)
• Drug effect (physiological reactions after the interaction of cell & drug)
• Onset time (time taken by drug to produce a therapeutic effect)
• Peak time (time taken by drug to reach at its maximum therapeutic response)
• Duration (time between the start and ending of a therapeutic response)

Terminology Used in Pharmacology

·       Absorption (dissolution of a drug into the blood)

·       AUC (Area Under Curve, measures of drug exposure)

·       Bioavailability (fraction of an administered dose that reaches the systemic circulation unchanged)

·       Bioequivalence (equal effect of two different drugs on the same biological body)

·       Clearance (measures of drug elimination in relation to the plasma)

·       Distribution Volume (factor that relates the amount of drug in the body to the concentration of plasma)

·       GFR (Glomerular Filtration Rate, kidney function)

·       Metabolism (breakdown and formation of new molecules)

·       Adverse Drug Reaction (undesirable effects of a drug)

·       Genotype (genetic constitution of an individual)

Classification of Drugs

Abbreviations Used in Pharmacology

Drug Dose Calculation

·       Basic Formula

o   (D/H) x V = A

§  A= Calculated amount to be given to the client

§  D= Desired dose (drug dose ordered by the health care provider)

§  V= Vehicle (drug form in which drug comes)

§  H= On hand (dose mentioned on the container)

·       Ratio and Proportion

o   H : V = D : X

§  H= on hand

§  V= Vehicle

§  D= Desired dose

§  X= Unknown amount to give

·       Fractional Equation

o   H/V = D/X

·       Body Weight

o   Client dose/day = (drug dose) x (body weight)

·       Body Surface Area

o   Client dose/day = (drug dose) x (square metre)

 

Fried’s Rule

·       Applies to the child younger than 1yr of age

·       Child Dose = {Infant age (months) x Adult average dose} x 150 months

Young’s Rule  

·       Applies to children 1-12 years old

·       Child Dose = {Childs age (yrs) x Adult average dose} x Childs age (yrs) + 12

Clark’s Rule

·       Uses child’s weight to calculate the dose and assumes that the adult dose is based on 150 lb person

·       Child Dose = {Childs weight (pounds) x Adult average dose} x 150lbs (pounds)

# To explore more knowledge kindly visit to our Facebook  page by clicking on https://www.facebook.com/profile.php?id=100089946602457&mibextid=ZbWKwL and don't  forget to like, follow & share this page.

Video description

     Don’t forget to do these things if you get benefitted from this article

o   Visit our Let’s contribute page https://keedainformation.blogspot.com/p/lets-contribute.html

o   Follow our  page

o   Like & comment on our post