Biodisposition

Biodisposition refers to the processes by which a substance, particularly a drug or xenobiotic (a foreign compound), is handled by a living organism. It encompasses the entire journey of the substance from its entry into the body to its eventual elimination. This process is typically broken down into four key stages: absorption, distribution, metabolism, and excretion, often abbreviated as ADME. Absorption is the process by which the substance enters the bloodstream from its site of administration. Distribution describes how the substance travels throughout the body and reaches various tissues and organs. Metabolism, also known as biotransformation, involves the chemical alteration of the substance by enzymes within the organism, often making it easier to eliminate. Excretion is the final removal of the substance and its metabolites from the body, primarily through urine, feces, or exhaled air. Understanding biodisposition is crucial in fields such as pharmacology and toxicology, as it directly influences the efficacy, duration of action, and potential toxicity of drugs and other chemicals. Factors like age, genetics, disease state, and co-administered substances can significantly impact an organism's biodisposition of a particular compound.