Recurrent symptomatic hypocalcemia during rifampicin therapy for brucellosis

Drug-associated hypocalcemia is rare, but may occur during routinely administered drugs. We reported a case of vertebral brucellosis, which developed two hypocalcemic episodes associated with hypokalemic alkalosis with two drug combinations including rifampicin. Possible underlying mechanisms of hypocalcemia were discussed. The patient had carpopedal spasm at both hypocalcemic presentations. Laboratory analysis revealed hypocalcemia, hypokalemia, alkalosis with hypercalciuria, and low-normal parathormone (PTH) at first and elevated PTH at the second admission. The patient improved with cessation of drugs and appropriate management of hypocalcemia and hypokalemia with calcium, vitamin D, magnesium, and potassium replacement. The underlying mechanism of hypocalcemia in this patient seemed to be due to tubular damage resulting with Bartter-like syndrome, which is well defined with aminogylcosides. But the recurrence of hypocalcemia with an aminoglycoside-free antibiotic combination including rifampicin suggests a possible role of rifampicin on hypocalcemia associated Bartter-like syndrome that has never been reported before.