Pharmacodynamics

Pharmacodynamics is the study of how a drug affects an organism, whereas Pharmacokinetics is the study of how the organism affects the drug. Both together influence dosing, benefit, and adverse effects.

Mechanisms of action

Pharmacodynamics is sometimes abbreviated as "PD" and its effects are often classified as either therapeutic or toxic. Pharmacodynamics can be split into two areas: (1) effects on the body and (2) effects on microorganisms such as bacteria, viruses, and fungi.

Drug concentration and effect

The relationship between the concentration of a drug and the response of the organism plays a key role in pharmacodynamic interactions. This relationship represents the body's response to increasing doses of a drug.

Drug-receptor interactions

The interaction of a drug with its receptor is fundamental to its pharmacodynamic effect. The nature of this interaction can vary, and different drugs may have different affinities for the same receptor, leading to a range of effects.

Drug resistance

Drug resistance is a significant concern in pharmacodynamics, particularly in the treatment of infections and cancer. It occurs when an organism develops a reduced sensitivity or resistance to a drug.

See also

• Pharmacokinetics
• Pharmacology
• Pharmaceutics
• Pharmacognosy
• Pharmacy
• Medicinal chemistry
• Pharmacotherapy
• Toxicology

References

• 
  Pharmacodynamics
• 
  Molecular mechanisms