VL1: Terminology

Study of Drugs, comes from the ancient Greek words

pharmakon and logia

Any substance that, when administered to living organisms, produces a change in function with the aim of preventing, diagnosing or treating disease.

Study of the processes of drug absorption, distribution, metabolism, and excretion.

Study of the action of drugs on living tissue

Study of the use of drugs in treating diseases.

Specific cellular structure that a drug binds to in order to produce or modulate a physiologic effect.

Drug that exerts its action by binding to a receptor and activating it.

Drug that decrease or oppose the actions of another drug

or endogenous ligand.

Degree to which a drug can bind to a receptor

Ability of a drug to affect a specific receptor or cell type without affecting other receptors or cells

Location within the body where a drug exerts its therapeutic effect

Explanation of how a drug produces its effects on a molecular level

Defines the chemical composition of a drug

molecule

Time from drug administration to the first observable drug effects

Period of time over which a drug continues to produce its effect after administration

General term for undesirable and potentially harmful drug effect

Desired drug effect to alleviate disease condition(s) or symptom of disease(s)

Range of drug dosage that provides clinical benefit to patients while minimizing the risk of adverse effects

A measure of relative drug safety. Calculated from the Ratio of the LD50 to the ED50 in animal studies.

A measurement of the amount of drug that is administered

Effective dose 50; The dose that produces an effect that is half of the maximal response

Lethal dose 50; The dose that will kill 50% of the laboratory animals tested in preclinical studies

A measurement of the dose, or concentration, of a drug required to produce a specific effect

Ability of a drug or treatment to produce the desired therapeutic effect

Time required for the concentration of a drug in the plasma to reduce by half

Fraction of an administered dose of a drug that reaches the systemic circulation in active form

A substance that is inactive in its administered form but becomes active after being metabolized in the bod

Intended or indicated uses for any drug

Situations or conditions when a certain drug should not be administered

A drug that can be dispensed without a prescription

drug for which dispensing requires a written or phone order that can only be issued by or under the direction of a licensed physician

drug gets destroyed in the liver before the therapeutic effect

• Natural sources

  • Plants: morphine from poppy plant…

  • Animals: Hormones like insulin from pigs or cows

  • Microorganisms: several antibiotics from bacteria and fungi

• Chemical synthesis: most drugs in the market are fully or semi synthesized in pharmaceutical labs

• Biotechnology-derived drugs: Biologics like recombinant proteins, monoclonal antibodies, vaccines, cell and gene therapies

1. Identification of new Drug Targets: mostly conducted in academic labs

2. Discovery or synthesis of a potential new drug compund:

   Rational Drug design: design of new molecules based on the knowlege of biological target

   High-troughput Screening: Testing large libaries of natural products and chemical compunds for biological activity

Preclinical safety and toxicity testing:

Assess potential risks of drug candidates before human trials by: - Identification of possible human toxicities. - Designing tests to understand mchanisms of drug toxicity. - Predicting toxicities to monitor in clinical trials.

Limitations:

- Time-consuming and costly. - Large numbers of animals often required. - Rare adverse effects may not be detected. - Extrapolating data from animals to humans is not always reliable.

Clinical Trials

- Only a small fraction of lead compounds enter clinical trials. - Clinical studies must adhere to stringent regulations and ethical guidelines.

Phase 1: - Conducted with 20–100 healthy volunteers. - Establishes safe dosage limits and identifies predictable toxicities.

Phase 2: - Focuses on efficacy in 100–200 patients with the target disease. - Includes placebos or active controls. - Highest rate of drug failures, with only 25% advancing to Phase 3.

Phase 3: - Involves thousands of patients to confirm safety and efficacy. - Expensive and complex with significant data collection.

Phase 4:

- Ongoing monitoring of drug safety in real-world settings. - Important for detecting rare adverse effects. - Monitoring may be inconsistent.

Patent considerations:

- In most cases the patent protection lasts 20 years. - Generic drugs can enter the market after patent expiration.