Ketoconazole decreases the serum ionized calcium and 1,25-dihydroxyvitamin D levels in tuberculosis-associated hypercalcemia
G. Saggese, S. Bertelloni, G. I. Baroncelli and G. Di Nero
Department of Pediatrics, University of Pisa, Italy.
OBJECTIVE--To evaluate whether tuberculosis-associated hypercalcemia is
related to abnormal synthesis of 1,25-dihydroxyvitamin D (1,25[OH]2D) and
whether ketoconazole administration may be useful in treating
tuberculosis-associated hypercalcemia. DESIGN--Case study.
SETTING--Endocrine Unit, Pediatric Clinic, University of Pisa (Italy).
PARTICIPANTS--Two boys (aged 10.5 years and 14.7 years) with active
tuberculosis and hypercalcemia. MEASUREMENTS/MAIN RESULTS--At admission,
serum 1,25-dihydroxyvitamin D levels were elevated. Oral ketoconazole
administration (3.0 mg/kg every 8 hours) decreased 1,25-dihydroxyvitamin D
levels within the first week of therapy (from 208.8 to 57.6 pmol/L [-72.4%]
in one boy and from 321.6 to 115.2 pmol/L [-64.2%] in the other). We also
found a coincident normalization of serum ionized calcium concentration
(from 1.45 to 1.24 mmol/L [-13.0%] in one boy and from 1.55 to 1.26 mmol/L
[-17.0%] in the other). CONCLUSIONS--Abnormal elevated levels of
1,25-dihydroxyvitamin D caused hypercalcemia in our patients; ketoconazole
administration may be effective in the treatment of hypercalcemia in
patients with tuberculosis, which decreases 1,25-dihydroxyvitamin D
synthesis.
