An elderly man had been treated for prostate cancer with radiation and neoadjuvant hormonal therapy. One year after the cessation of radiation therapy, the PSA value was found to be elevated. A non-steroidal antiandrogen bicalutamide was initiated to the patient. Due to poor treatment response the drug was changed for the GnRH agonist leuprorelin acetate, which upon injection caused a sudden deterioration of the patient's general condition. He was delirious and in pain, and was diagnosed with leukocytosis, hypokalemia, hyperglycemia and metabolic alkalosis. The patient was referred to the endocrinological clinic for evaluation of the metabolic-endocrinological problems. He succumbed to disseminated prostate cancer.