Pharmacokinetics refers to the processes involved in the movement of a drug within the body. It includes:
1. Absorption: This is the process by which the drug enters the bloodstream from the site of administration, such as the gastrointestinal tract or skin.
2. Distribution: After absorption, the drug is distributed throughout the body via the bloodstream to reach its target organs or tissues.
3. Metabolism: Metabolism refers to the chemical transformations that a drug undergoes in the body, often in the liver, to convert it into metabolites that can be easily excreted.
4. Excretion: This is the removal of the drug and its metabolites from the body, mainly through the kidneys in the form of urine, or through bile in the feces.
Understanding pharmacokinetics is crucial in determining the dosage regimen, timing of administration, and potential interactions of drugs within the body. It does not specifically refer to the adverse effects of a drug, its action on the body, or its selective action on receptors, but rather the journey of the drug through the body's systems.
