This document discusses pharmacokinetics and pharmacodynamics, the two major branches of pharmacology. Pharmacokinetics refers to how the body affects a drug, through absorption, distribution, metabolism and excretion. Pharmacodynamics refers to how drugs act on the body through their pharmacological effects, efficacy and toxicity. Factors like a drug's properties, route of administration and the body's enzymes impact its pharmacokinetics and pharmacodynamics. Understanding these principles provides a foundation for medical treatments.

1. Pharmacokinetics
& Pharmacodynamics
A presentation by Partoredjo Orisia

2. Introduction
The efficacy and safety of a specific drug depend
heavily on pharmacokinetics and pharmacodynamics,
the two major branches of pharmacology.
Pharmacology is the study of how chemical agents,
both natural and synthetic, affect biological systems.
The scientific knowledge gained through
pharmacologic studies provides a foundation for a
number of medical treatments and is of great
importance in this day and age.

3. Difference between Pharmacokinetics and Pharmacodynamics
• Pharmacokinetics:
Pharmakon | Greek
The branch of pharmacology concerned with the movement of drugs within the body.
- Absorption
- Distribution
- Metabolism
- Excretion
• Pharmacodynamics:
The branch of pharmacology concerned with the effects of drugs and the mechanism of their action.
- Pharmacologic effect
- Drug efficacy
- Drug toxicity

4. Absorption
• The transfer of a drug from its site of administration to the
blood stream.
Mechanisms making absorption possible:
• Passive diffusion
• Facilitated diffusion
• Active transport
Factors affecting absorption:
• Drug properties: lipid solubility, molecular weight, etc.
• Blood flow to the absorption site
• Route of drug administration
Pharmacokinetics

5. Absorption cont.
According to the rate of absorption:
Oral Intramuscular Inhalation
Conclusion: The dose of the drug remains the same, but some
routes of administration spread the dose out in a greater length of
time.

6. Distribution
• The passage of a drug from the circulation to tissue (e.g. fat,
muscles) and site of its action.
Understanding drug distribution is important in establishing: the
amount of drug available to the target organ to produce action
During the transport of a drug, the drug undergoes both passive
diffusion and active transport until an equilibrium is reached
between unbound drugs in plasma and tissue fluid.

7. Metabolism
• Chemical alteration of the drug in the body to make the drug
easier to excrete.
The majority of metabolic processes that involve drugs occur in
the liver, as the enzymes that facilitate the reactions are
concentrated there.
Phase 1: Reactions of drug metabolism involve oxidation,
reduction, or hydrolysis of the parent drug. The resulting active
metabolites produce the desired therapeutic effects.
Phase 2: Reactions involve conjugation by coupling the drug or
its metabolites to another molecule, resulting in inactive
metabolites.

8. Excretion
• Irriversable removal of drugs from the body
It is accomplished in many ways:
• Exhalation (luchtwegen)
• Biliary secretion (gal)
• Renal clearance (nier)
• Excretion in sweat, breastmilk, saliva, etc. Excretion organs

11. Functional proteins that are targets of drug action
• Enzymes
• Ion channels
• Transporter proteins
• Membrane receptors

12. Pharmacologic effect
• the physiological and/or biochemical changes in the body produced by a drug in
therapeutic concentration.
• Pharmacodynamics is often referred to as “what the drug does to the body”.
• The pharmacologic response depends on the drug binding to its target. The concentration
of the drug at the receptor site influences the drug’s effect.

13. Drug Efficacy
• the ability of a drug to produce the desired beneficial effect.
Factors affecting the efficacy of drugs:
• Type of drug
• Body weight
• Age
• Tolerance
• The effects of each drug last for different amounts of time.
• Interactions with other drugs
• General Health

14. Drug Toxicity
• a diverse array of adverse effects which are brought about through drug use at either
therapeutic or non-therapeutic doses
Drug toxicity may occur when:
• a person has consumed a dose of a drug that is too high for them to handle.
• the person's liver and/or kidneys are unable to function properly and get the drug out of
the bloodstream.

15. References
• https://www.sciencedirect.com/sdfe/pdf/download/eid/1-s2.0-0163725881900978/first-
page-pdf
• https://www.bioagilytix.com/2020/10/05/the-difference-between-pharmacokinetics-and-
pharmacodynamics/
• https://www.msdmanuals.com/professional/clinical-
pharmacology/pharmacodynamics/overview-of-pharmacodynamics
• https://www.sciencedirect.com/topics/medicine-and-dentistry/pharmacodynamics
• https://www.jstor.org/stable/envirevi.7.1.1?seq=1
• https://www.ashp.org/-/media/store%20files/p2418-sample-chapter-1.pdf