Drug Pharmacology

Introduction

As I have worked longer in the profession, I have come to appreciate the importance of understanding drug pharmacology.

• This knowledge can help me to make better clinical judgements and ultimately recommend more effective products to my patients.

Drug pharmacology is the study of drugs and their effects on living organims. It is a complex and ever-evolving field that can be divided into 2 main branches: pharmacodynamics and pharmacokinetics.

• Pharmacodynamics is the study of how drug interact with the body. This includes the study of drug receptors, drug metabolism, and drug-drug interaction.
• Pharmacokinetics is the study of how the body handles drugs. This includes the study of drug absorption, distribution, metabolism and elimination.

Case Discussion

A few weeks ago, a customer asked me why a doctor might prescribe might prescribe oral rehydration salt, activated charcoal, Smecta or Hidrasec to treat a child with food poisoning and diarrhea.

It is easier to justify the prescribing practice of giving oral rehydration salt with adjunct therapies when we explain the drug's mechanism of action to patients in lay man terms.

• Oral rehydration salt replaces lost electrolyte and fluids, which is the key management strategy of diarrhea.
• Activated charcoal adsorbs toxic substances remaining in the gut, thus inhibiting GI absorption and limiting systemic toxicity.
• Smecta (Diosmectite) works by coating the lining of the intestine. It binds to viruses and bacteria, eliminates the pathogens through the stools, then protects the mucosa from irritation and allows it to recover.
• Hidrasec (Racecadotril) is an enkephalinase inhibitor that inhibits the breakdown of endogenous opioids, thus reducing intestinal secretions.

Patients do not expect pharmacists to explain complex topics like the Kreb cycle or GPCR receptors in detail.

University Syllabus

Reflecting on my university syllabus, clinical therapeutic units have a basic structure of

• Physiology - Teaches us how our human body works.
• Pathophyiosiology - What went wrong in the disease states?
• Drug - Explains how the drug acts to rectify the issues.
• Therapeutic guidelines - Clinical recommendations based on evidences (benefits versus harms).

To illustrate, insulin plays many important roles in the body, such as lowering blood glucose, inhibiting glycogenolysis and gluconeogenesis and stimulating glycogen synthesis.

• In type 1 diabetes, the body's immune system attacks and destroys the cells in the pancreas that produce insulin. This results in a lack of insulin, which leads to high blood sugar levels.
• The main treatment for type 1 diabetes is insulin supplementation, along with diet and exercise.
• The goal of insulin therapy is to mimic normal human physiology as closely as possible.

Nonetheless, science does not explain why things happens, but it explains how things happen.

• There are many discovered drugs which work miraculously yet we could not fully understand the complex mechanisms behind them.

Summary

Patients often come to the pharmacy to learn more about their drug treatment.

• As a pharmacist, it is important to be able to explain the basics of drug pharmacology to patients in a way that they can understand, addressing potential benefits and risks of medications.
• This can help patients to make informed decisions about their treatment and improve their adherence to medication regimens.