Pharmacology: Bioavailability

Introduction

Drug Properties

Physiology

Medicine Properties

Bioavailability

Activity

Assessment

Resources

Bioavailability

We are now able to discuss bioavailability itself.

Bioavailability is defined as the fraction of an administered dose that reaches the systemic circulation. If we plot graphs of plasma concentration against time for the same drug administered intravenously and orally, the bioavailability of the oral drug is the ratio of the area beneath the oral dose curve compared to that beneath the intravenous dose curve. This is because by definition the bioavailability of a drug administered intravenously is 100 percent.