CALCIUM SUPPLEMENTATION AND OTOTOXICITY IN PATIENTS RECEIVING CISPLATIN

We have studied the effect on ototoxicity of maintaining serum calcium concentration by calcium gluconate infusion in cancer patients receiv ing high-dose cisplatin in a randomized study in two groups: 11 patien ts received calcium gluconate, 4 mg kg(-1) i.v. infusion during cispla tin therapy; 11 other patients without any calcium supplementation ser ved as controls. All of them received the first course of chemotherapy , based on cisplatin, 120 mg m(2) with a hydration schedule. An audiog ram was performed in each patient just before cisplatin and repeated a fter 1 day and 3 weeks. Mean total calcium concentration in control pa tients before and after chemotherapy was 2.2 +/- 0.14 (95% confidence interval 1.9-2.5) and 2.0 +/- 0.13 (95% CI 1.7-2.24) mmol l(-1) respec tively (P = 0.0004) and for ionized calcium 1.22 +/- 0.52 (95% CI 0.21 -2.23) and 1.11 +/- 0.07 (95% CI 0.97-1.25) mmol l(-1) respectively (P = 0.0005). Serum magnesium levels were maintained or increased by mag nesium supplementation. Although there was no change in serum total or ionized calcium, or serum magnesium in the calcium infusion group, no differences in hearing loss between the groups were observed. High-do se cisplatin chemotherapy for cancer patients induces an acute decreas e of serum total calcium and serum ionized calcium and audiometric cha nges. Maintenance of calcium serum levels by calcium gluconate infusio n did not protect against ototoxicity in those patients.