Parameters of Calcium Metabolism Fluctuated during Initiation or Changing of Antipsychotic Drugs

OBJECTIVE: Serum parameters of calcium homeostasis were measured based on previously published evidence linking osteoporotic fractures and/or bone/mineral loss with antipsychotics. METHODS: Prospective, four-week, time-series trial was conducted and study population consisted of patients of both genders, aged 35-85 years, admitted within the routine practice, with acute psychotic symptoms, to whom an antipsychotic drug was either introduced or substituted. Serial measurements of serum calcium, phosphorous, magnesium, 25(OH)D, parathyroid hormone, calcitonin, osteocalcin and C-telopeptide were made from patient venous blood samples. RESULTS: Calcium serum concentrations significantly decreased from baseline to the fourth week (2.42±0.12 vs. 2.33±0.16 mmol/L, p=0.022, n=25). The mean of all calcemia changes from the baseline was -2.6±5.7% (-24.1 to 7.7) with more decreases than increases (78 vs. 49, p=0.010) and more patents having negative sum of calcemia changes from baseline (n=28) than positive ones (n=10) (p=0.004). There were simultaneous falls of calcium and magnesium from baseline (63/15 vs. 23/26, p<0.001; OR=4.75, 95% CI 2.14-10.51), phosphorous (45/33 vs. 9/40, p<0.001; 6.06, 2.59-14.20) and 25(OH)D concentrations (57/21 vs. 13/35, p<0.001; 7.31, 3.25-16.42), respectively. Calcemia positively correlated with magnesemia, phosphatemia and 25(OH)D values. Parathyroid hormone and C-telopeptide showed only subtle oscillations of their absolute concentrations or changes from baseline; calcitonin and osteocalcin did not change. Adjustment of final calcemia trend (depletion/accumulation) for relevant risk factors, generally, did not change the results. CONCLUSION: In patients with psychotic disorders and several risks for bone metabolism disturbances antipsychotic treatment was associated with the decrease of calcemia and changes in levels of the associated ions.