Absorption of furosemide from the gastrointestinal tract is fairly rapid. Bioavailability is reported as 60-70%, but is variable and not predictable. The rate and extent of absorption show a large intra- and inter-individual variability and are influenced by dosage form, underlying diseases, and by the presence of food after oral administration. Results obtained with an animal model indicate that furosemide administered into the stomach is more rapidly absorbed than if is is administered into the small intestine.