Pharmacology Basics: Receptors, Dosing, and Drug Marketability

Fundamentals of Drug Treatment and Pharmacology

What Are Drugs?

Drugs are products used to cure, alleviate, prevent, or diagnose disease. Medicines contain one or more active principles (APIs)—substances that give the drugs their therapeutic properties.

Adverse Reactions and Drug Safety

All medicines can cause Adverse Reactions, which are negative effects of the drugs. In order to market a drug, health authorities must ensure that its benefits significantly outweigh any possible adverse reactions.

Dosing, Efficacy, and Drug Interactions

Each drug has an optimal dose. Increasing the dose does not necessarily increase benefits; however, it often increases the risk of adverse reactions.

There are drugs that interfere with each other if given together. For example, one drug may cause another not to absorb properly. However, these drug interactions are usually known and managed by healthcare professionals.

Mechanism of Action and Drug Administration

How Drugs Work: Receptor Binding

Drugs have the ability to bind to molecules in the body called receptors. These molecules (usually proteins) change their functions when drugs bind to them. There are receptors found throughout the body, and others only in very specific groups of cells.

Barriers and Administration Routes

Drugs must pass through various barriers, such as the gastrointestinal wall, the walls of blood vessels, etc. Some barriers can be bypassed by changing the route of drug administration.

Common administration routes include:

• Oral: Capsules, tablets.
• Sublingual
• Rectal: Suppository.
• Injection: Subcutaneous, intramuscular, or intravenous.
• Topical: Intranasal or skin (ointments).

Research and Development of New Medicines

The Search for Drug Specificity

Pharmacology research shows that drugs can produce adverse reactions because they often bind to multiple receptors (e.g., a pain reliever causing drowsiness). Researchers are currently looking for highly specific drugs—those that bind to only one type of receptor—in order to minimize adverse effects and maximize therapeutic benefit.

Pharmaceutical Industry: Patents and Generics

Most pharmaceutical research is carried out by major pharmaceutical companies, often resulting in large economic benefits.

Bringing a Drug to Market: The Testing Process

For a drug to be marketable, it must pass a rigorous testing process:

1. Tests in experimental animals and healthy human volunteers (preclinical stage).
2. If results are good, the drug proceeds to the clinical trial stage, testing with patients.
3. If these tests indicate that the drug is safe and effective, marketing approval is granted.

Drug Patents and Generic Medicines

When a company discovers a new drug, it claims a patent. This allows the company to be the sole manufacturer and marketer for a period of between 10 and 20 years.

When this period ends, other laboratories can produce the drug, which is then called a generic medicine. Generic medicines contain the same active principle as the original but are typically cheaper.