Chapters and Topics in General Pharmacology

Introduction to General Pharmacology

General pharmacology covers the fundamental principles of pharmacology, including Drug discovery and development, Souces of Drugs, Dosage forms, Routes of drug administration, Pharmacokinetics, Clinical Pharmacokinetics, Pharmacodynamics, Drug interactions and Adverse drug reactions (ADRs). Understanding these principles is crucial for healthcare professionals, researchers, and students to act safely and effectively using medications.

Drug Discovery and Development

The Comprehensive Guide to Drug Discovery, Development, and Clinical Trials: Everything You Need to Know

Drug Design and Screening

1. Rational drug design
2. High-throughput screening
3. Structure-activity relationships (SAR)

Phases of Clinical Trials

1. Phase I: Safety and dosage
2. Phase II: Efficacy and side effects
3. Phase III: Efficacy, monitoring, and comparison
4. Phase IV: Post-marketing surveillance

Click here for Drug discovery and Development page

Sources of Drugs

Various Sources of Drugs

Drugs are substances that are used to treat or prevent diseases, relieve symptoms, or improve the overall health and well-being of individuals. There are several sources of drugs, including natural sources, synthetic sources, and semi-synthetic sources.

Click here for the detailed page on Sources of Drugs

Dosage Forms

Dosage Forms of the Drugs

Dosage forms refer to the different physical forms in which medications are prepared and administered. Some common dosage forms include tablets, capsules, syrups, injections, and patches.

Click here for the detailed page on Dosage forms

Routes of Drug Administration

Routes of Drug Administration

Click here for the detailed page on Routes of drug administration

Enteral Routes	Description	Few Examples
Oral	Medication is taken by mouth in the form of tablets, capsules, or syrups	Aspirin, Paracetamol, Antibiotics
Sublingual	Medication is placed under the tongue to dissolve and be absorbed through the mucous membranes	Nitroglycerin, Vitamin B12
Rectal	Medication is inserted into the rectum in the form of suppositories or enemas	Anti-inflammatory drugs, Laxatives

Parenteral Routes:

Parenteral Routes	Description	Few Examples
Intravenous (IV)	Medication is injected directly into a vein using a needle and syringe	Chemotherapy drugs, Painkillers
Intramuscular (IM)	Medication is injected into a muscle using a needle and syringe	Vaccines, Antibiotics
Subcutaneous (SC)	Medication is injected under the skin using a needle and syringe	Insulin, Heparin
Transdermal	Medication is applied to the skin in the form of a patch or cream	Nicotine patches, Hormone replacement therapy
Inhalation	Medication is breathed in as a mist or aerosol	Asthma medications, Anesthetics

Pharmacokinetics

Pharmacokinetics – What the body does to Drug?

Pharmacokinetics is the study of how drugs are Absorbed, Distributed, Metabolised, and Eliminated (ADME) by the body. “It is also called what the body does to the body“. It involves the examination of how drugs move through the body, including how they are absorbed from the Gastrointestinal tract (GIT) and other sites of administration into the bloodstream, distributed to various organs and tissues, broken down/metabolised by the body’s enzymes, and eliminated through the various routes including urine, feces, or breath.

The study of pharmacokinetics helps:

• Determine the most effective dosage and frequency of a drug and

• Understand the potential risks and side effects associated with its use.

Absorption

1. Passive diffusion
2. Facilitated diffusion
3. Active transport
4. Endocytosis and exocytosis
5. Factors affecting the drug absorption

Factors Affecting Oral Drug Absorption and its Bioavailability

Distribution

1. Plasma protein binding
2. Volume of distribution
3. Tissue and organ barriers

Metabolism

1. Phase I reactions: Oxidation, reduction, and hydrolysis
2. Phase II reactions: Conjugation
3. Enzyme induction and inhibition
4. Genetic polymorphisms

Excretion

1. Renal excretion
2. Biliary excretion
3. Other routes of excretion

Click here for the Pharmacokinetics page

Click here for the Factors affecting drug absorption page

Clinical Pharmacokinetics

Clinical Pharmacokinetics

Click here for a detailed page on clinical pharmacokinetics

Pharmacodynamics

Pharmacodynamics: Understanding What Drug Does to the Body

Pharmacodynamics is the study of how drugs interact with the body at the molecular, cellular, and systemic levels to produce their effects. One of the fundamental aspects of pharmacodynamics is drug-receptor interactions, which are the binding of a drug molecule to a specific receptor on a cell or tissue. This interaction can activate or inhibit the receptor and trigger downstream signaling pathways, ultimately leading to the drug’s pharmacological effects.

Drug-Receptor Interactions

1. Types of receptors
2. Agonists and antagonists
3. Partial agonists and inverse agonists
4. Allosteric modulation

Dose-Response Relationships

1. Graded dose-response
2. Quantal dose-response
3. Therapeutic index
4. Potency and efficacy

Signal Transduction Mechanisms

1. G protein-coupled receptors (GPCRs)
2. Ion channels
3. Enzyme-linked receptors
4. Intracellular receptors

For a detailed page on Pharmacodynamics, please click here

Drug Interactions

Drug Interactions

1. Pharmacokinetic interactions
2. Pharmacodynamic interactions
3. Additive, synergistic, and antagonistic effects
4. Drug-food and drug-disease interactions

Click here for more information on Drug interactions

Adverse Drug Reactions (ADRs)

Adverse Drug Reactions

1. Types of adverse drug reactions
2. Mechanisms of adverse drug reactions
3. Risk factors for adverse drug reactions
4. Monitoring and reporting of adverse drug reactions

Click here for more information on ADRs

Factors Modifying Drug Action (click here to go to this page)

Conclusion

General pharmacology lays the foundation for understanding the principles of drug actions and their interactions with living organisms. This article has provided an overview of the key chapters and topics in general pharmacology, including drug discovery and development, pharmacokinetics, pharmacodynamics, drug interactions, adverse drug reactions, and drug regulation. A strong grasp of these topics is essential for healthcare professionals, researchers, and students to safely and effectively use medications in clinical practice.

Disclaimer: This article is for informational purposes only and should not be taken as medical advice. Always consult with a healthcare professional before making any decisions related to medication or treatment.