In which of the following body fluids the drug will be distributed?
A 34-year-old patient is about to receive a morphine injection because of a sharp abdominal pain apparently due to a renal colic. Morphine is a basic drug that crosses the cell membrane by lipid diffusion and has a Vd of about 230 liters (for a 70 kg person).
A. Cerebrospinal fluid B. Plasma C. Extracellular fluids D. Cell cytosol E. Total body water
Cell cytosol-7) learning objective:: explain why the vd can predict to a certain extent the pattern ofdistribution of a drug in the body.answer: dsince the total body water is about 42 liters for a 70 kg person, a volume of distribution higherthan 42 liters means that the drug is concentrated inside the body cells, even if the high vdcannot indicate the specific cells where the drug is concentrated.a) as stated above the vd cannot predict the organ where a drug can be preferentiallydistributed. in fact even if morphine the primary site of action of morphine is the cns, only smallquantities of the drug cross the blood brain barrier.b) a drug distributed in plasma would have a vd of about 3 liters.c) a drug distributed in the extracellular fluid would have a vd of about 13 liters.e) (see explanation above)