Question

To kill a cancer cell, the cytosol must have a concentration of at least 5nM of doxorubicin. For a cell with active ABC transporters what must the doxorubicin concentration OUTSIDE the cell be in order to kill the cancer?

Based off this answer, answer this question.

Doxorubicin has been known to also cause caradic arrest when the dose creates a serum level (level of extracellular concentration) of 0.5 mM. Would the required dose of dox. needed in the above question to kill drug resistant cancer cells also cause caradiac arrest in the patient?

Answer 1

The answer is NO.Since ABC transporters are active transporters,they always keep the intracellular concentration of doxorubicin higher than the extra cellular concentration.That's why,the dose required to kill cancer cells will not cause cardiotoxicity.Further,all drugs have a therapeutic index which is a measure of safety of drug.If a drug is causing cardiac arrest at the same dose at which it is killing the cancer cells,it will never be used for treating cancer.Hence no need of calculation.You can understand it just by thinking about therapeutic index of a drug.