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.
Antibiotics usually start working in 24 to 36 hours.... Antibiotics usually start working in 24 to 36 hours, however when the infection is in a tooth or jaw (bone) it takes longer merely because the blood supply isn`t as good in that kind of tissue. Warm compresses help to increase the blood flow to the area and carry the meds to the area.