[Hypomagnesemia following chemotherapy of disseminated testicular tumors].

Sixteen patients with metastatic testicular cancer were treated with combination chemotherapy including cisplatin (CDDP) at 3- to 4-week intervals for two to five courses. There was a sequential fall in serum magnesium with each course of therapy: 13 of the 16 patients (81%) became hypomagnesemic, and the median magnesium nadir was 1.67 mg/dl. Serum magnesium nadir levels gradually decreased according to the cumulative CDDP dose. Acute clinical effects of the hypomagnesemia were observed in 4 patients, 2 of them complained of neuromuscular disturbance in the extremities, one of cardiac arrhythmia, and the other of Raynaud's phenomenon. The median time to the onset of hypomagnesemia was 67 days and the duration of hypomagnesemia was 24 days. The creatinine clearance (Ccr) decreased gradually according to the cumulative CDDP dose, and the mean Ccr declined from 87.2 ml/min before therapy to 55.8 ml/min. In 3 out of 16 patients, an irreversible decrease to below 50 ml/min was seen after chemotherapy. In patients with normal renal function treated by VAB-6 regimen, creatinine clearance (Ccr) decreased transiently during each course of chemotherapy and returned to the pretreatment level during the interval. The mean creatinine clearance declined from 90.7 ml/min before therapy to 82.9 ml/min after three courses of induction chemotherapy. Urinary excretion of beta 2 microglobulin (beta 2MG) increased transiently before Ccr began to decrease during each course of chemotherapy. Serum potassium and calcium concentrations decreased transiently probably due to urinary losses but there was no significant relationship between hypopotassemia, hypocalcemia and hypomagnesemia.(ABSTRACT TRUNCATED AT 250 WORDS)