By administering cough syrup to breast cancer patients, doctors can more easily determine the dose of the cancer drug tamoxifen they need, the BBC News reports.
Tamoxifen is a drug that has greatly improved breast cancer treatment outcomes. It blocks the action of the female sex hormone estrogen, which can stimulate the growth of some tumors. However, to be effective, tamoxifen must be metabolized by the body. Not all patients metabolise this drug equally effectively.
Tamoxifen undergoes metabolic changes in the body – hydroxylation, demethylation and conjugation, resulting in the formation of new chemicals.
So far, there has been no easy way to judge who metabolizes tamoxifen faster and who metabolizes slower, making it difficult to select the optimal dose. Now, Dutch scientists at the Erasmus Medical Center in Rotterdam have come up with the idea to use the antitussive drug dextromethorphan (a common ingredient in cough syrups) as a tamoxifen simulator.
Compared to tamoxifen, dextromethorphan is practically harmless and is metabolized in exactly the same way. Therefore, by measuring the level of cough medicine in a patient’s blood, one can predict what the level of tamoxifen will be.
In the case of poor metabolism of dextromethorphan, the dose of tamoxifen may be increased or another drug may be used. (PAP)