The prevalence, mechanism and clinical significance of lithium-induced hypercalcaemia
Mcintosh, W.B.; Horn, E.H.; Mathieson, L.M.; Sumner, D.
Medical Laboratory Sciences 44(2): 115-118
1987
ISSN/ISBN: 0308-3616 PMID: 3695842 Document Number: 297334
Hypercalcaemia was found in five (8%) of 61 patients receiving long-term lithium therapy for manic-depressive illness. Compared with a control group of 41 psychiatric in-patients, patients on lithium had significantly higher mean concentrations of serum ionised calcium, creatinine, parathormone and TSH and a lower mean concentration of serum bicarbonate. Derived parameters for the renal tubular reabsorption of phosphate (TmPO4/GFR) and the urine calcium/creatinine ratio were significantly lower in the lithium group. Mean serum alkaline phosphatase activities and urine hydroxyproline/creatinine ratios were similar in both groups. Lithium therapy appears to produce mild hyperparathyroidism which has no significant effect on bone osteoblastic activity or resorption. Parathyroid adenomata may be induced in a small number of patients.