Introduction to Pharmacodynamics & Pharmacokinetics
Pharmacokinetics and pharmacodynamics are the studies of how drugs are absorbed, distributed, metabolized, and excreted by different organs in the body.
Pharmacodynamics is the study of how a drug affects the body and its systems. Pharmacokinetics is the study of how a drug moves through the body and its systems.
Pharmacokinetics is typically measured in terms of volume, time, and concentration. The volume refers to how much fluid or blood flow there is for a substance to move through. The time refers to how long it takes for a substance to move through the system. And concentration refers to how much of the substance there is in relation to other substances in that fluid or blood flow.
What is Pharmacokinetics?
Pharmacokinetics is the study of what happens to a drug after it enters the body.
Pharmacokinetics can be broken down into three phases: absorption, distribution, and elimination.
Absorption occurs when the drug enters the bloodstream and begins travelling to other parts of the body. Distribution refers to how drugs are distributed throughout different tissues in your body. Elimination is when your body eliminates or breaks down a drug so that it can be excreted from your system.
What is Pharmacodynamics?
Pharmacodynamics is the study of the biochemical and physiologic effects of drugs.
Pharmacodynamics is the study of how a drug affects an organism. It deals with such questions as: What is the effect of a drug on what organ or system? How does it produce this effect? What are its side effects? The word “pharmacodynamics” comes from Greek: pharmakon, meaning “drug”, and dynamis, meaning “power”.
The Relationship between Pharmacokinetics and Pharmacodynamics
Pharmacokinetics is the study of the absorption, distribution, metabolism and excretion of drugs. Pharmacodynamics is the study of what a drug does to living tissues. These two concepts are sometimes used interchangeably but they are not exactly the same.
Pharmacokinetics deals with what happens to a drug after it is administered whereas pharmacodynamics deals with what the drug does once it has been administered. For example, if someone takes an opioid like morphine and their breathing slows down then that would be an effect of the drug’s pharmacodynamics but not its pharmacokinetics.
Pharmaceuticals in the Body
Pharmaceuticals are a significant and growing presence in the human body. They can be found in our blood plasma, synovial fluid, and even breast milk.
Pharmaceuticals are used for a variety of reasons. Some are prescribed by doctors to treat diseases or disorders. Others may be taken as vitamins or supplements to maintain health. Still others may be used recreationally without a prescription to get high or experience other effects.
The Effect of Drug-Drug Interaction on Therapeutic Response
Drug-drug interactions are situations in which the effect of a drug is either increased or decreased by another drug, food, or substance.
The most common types of drug-drug interactions are pharmacokinetic and pharmacodynamic interactions. Pharmacokinetic interactions occur when one drug alters the absorption, distribution, metabolism, or excretion of another. Pharmacodynamic interactions occur when one drug alters the response to another.
Factors affecting pharmacokinetics and pharmacodynamics
Pharmacokinetics is the study of what happens to a drug after it is administered and how it is absorbed, distributed, metabolized, and excreted. Pharmacodynamics is the study of how drugs interact with receptors in the body to produce a response.
Factors that affect pharmacokinetics are:
- Route of administration
- Absorption
- Distribution
Factors that affect pharmacodynamics are:
- Drug interactions with receptors in the body
- Presence of other drugs
Conclusion: Final Thought on Pharmacokinetics and Pharmacodynamics
The conclusion of this paper is that the pharmacokinetics and pharmacodynamics of a drug are two important factors in drug development. They are both equally important in determining the efficacy of a drug.