I have metastatic bc. i am very drug-sensitive. i have had a hard time with any drugs given for cancer. can my dr do a cytochrome p450 test to determine how a drug metabolizes? 4 drugs were tried and i have had severe reactions?

Your request is very reasonable, and such metabolic blood studies are readily available. Some of these surveys will also reveal potential drug-drug interactions. One salient issue will involve insurance coverage. Explore this with your oncologist or internist.

All drugs are metabolized through the liver, kidneys or a combination of them. Drug-drug interactions and side effects are somewhat predictable, but in your case 2 things may be adding up: 1. The need to take extra risk given the condition you suffer from and 2. The likelihood of having side effects and undesirable side effects independent of cyt. P450. Your oncologist remains your best reference.