Effect of cytotoxic drugs on the function of the hypothalamo-pituitary-adrenal axis

We measured the serum concentration of thyroid-stimulating hormone (TSH), its response to exogenic TSH-releasing hormone (TRH), as well as cortisol plasma levels before and after stimulation with adrenocorticotrophic hormone in 15 patients before, during and after a chemotherapeutic cycle. 3/6 patients receiving only cytotoxic drugs developed a marked suppression of the TSH response to TRH and 1 of these patients showed an impairment of the adrenal function under chemotherapy. This was also observed in 7/9 patients receiving both cytotoxic drugs and corticosteroids; however, the individual pattern of the impairment was quite variable. 5/9 patients in this group developed a suppression of the TSH response to TRH. Impairment of the hypothalamo-pituitary-adrenal axis function under cytotoxic drugs and/or corticosteroids occurs with great variability and the mechanisms involved in its etiology are not yet fully understood.