Important Ideas to Know in Introductory Pharmacology

1. What is Pharmacology?
   Pharmacology is a part of medicine that looks at how drugs work in the body. It helps us understand how drugs act, their side effects, how they can help people, and even how they can be harmful. This knowledge is key to creating new medicines and improving how we care for patients.

2. Types of Drugs
   Drugs are grouped into different categories based on how they work and what they are made of. Here are some common types:

   • Pain Relievers (Analgesics): These help reduce pain. Examples include acetaminophen and ibuprofen.
   • Antibiotics: These are used to treat infections caused by bacteria. Examples are penicillin and ciprofloxacin.
   • Antidepressants: These help with mood problems. Examples include fluoxetine and sertraline.

3. Pharmacokinetics
   This term explains how the body changes a drug over time. It includes four main steps:

   • Absorption: How the drug gets into the bloodstream.
   • Distribution: How the drug spreads through the body’s fluids and tissues.
   • Metabolism: How the body changes the drug, mostly in the liver.
   • Excretion: How the body gets rid of the drug, mainly through the kidneys.

   The “half-life” of a drug is the time it takes for the amount of the drug in the blood to drop by half. For example, ibuprofen’s half-life is about 2 hours, while diazepam’s half-life can be between 20 to 50 hours.

4. Pharmacodynamics
   This part looks at what the drug does to the body. It includes how the drug works and how its effects change with different amounts. Some key terms are:

   • Receptor: A special protein that helps the drug work in the body.
   • Agonist: A substance that activates a receptor, leading to a response in the body.
   • Antagonist: A substance that blocks a receptor, preventing a response.

5. Therapeutic Index
   This term measures the safety of a drug. It’s the difference between a dose that helps people and a dose that can be harmful. A higher therapeutic index means the drug is safer. For example, if a drug has a therapeutic index of 10, that means the dose that could be deadly is 10 times stronger than the dose that helps. This makes understanding dosages very important.

6. Adverse Drug Reactions (ADRs)
   ADRs are unwanted effects that can happen when taking a drug. About 10% of patients in hospitals may experience an ADR, and these can make treatment harder and increase healthcare costs.

Knowing these basic ideas about pharmacology is really important for medical students. They help build a strong foundation for safe and effective patient care.