Apparent volume of distribution, V. We can use Equation 5.7.1 to calculate the plasma concentration at any time when we know kel and Cp0. However, usually we don't know Cp0 ahead of time, but we do know the dose. A dose in mass units, maybe in mg. To calculate Cp0 we need to know the volume that the drug is distributed into. That is, the apparent volume of the mixing container, the body. This apparent volume of distribution is not a physiological volume. It won't be lower than blood or plasma volume but for some drugs it can be much larger than body volume.
How long after starting antibiotics for a kidney infection should back, side, and abdominal pain go away? It could take up to 3 days depending on the medication. Most people feel slight relief after 24 hours. You should have a follow up with your MD to check that the infection isn't resistant to antibiotics, and is indeed gone. If you are still having minor pain, that is a great time to talk to him.
1 doctor agreed: Kidney Infection: Kidney infections characterized by fever and flank pain require antibiotic treatment. If severe, hospitalization can be necessary. A urine culture is often needed to help choose the correct antibiotic.