Final answer:
Bioavailability refers to the percentage of a drug that reaches systemic circulation and is available to exert its intended effect. It is influenced by factors such as the route of administration and drug formulation. Measuring bioavailability is important for dosage adjustment and drug formulation optimization.
Step-by-step explanation:
The term bioavailability refers to the fraction or percentage of a drug that reaches systemic circulation and is available to exert its intended effect. It is a pharmacokinetic parameter that describes the extent and rate at which a drug is absorbed into the bloodstream after administration.
Bioavailability is influenced by several factors such as the route of administration, drug formulation, and first-pass metabolism in the liver. For example, drugs administered orally may undergo partial degradation in the gastrointestinal tract before reaching systemic circulation, leading to lower bioavailability compared to intravenous administration.
Measuring bioavailability is important for therapeutic drug monitoring to ensure that patients are receiving an appropriate dose to achieve the desired therapeutic effect. It also helps in the development and optimization of drug formulations to enhance efficacy and minimize side effects.