Denosumab protocol reduces hypocalcaemia incidence in postmenopausal women
The incidence of denosumab-related hypocalcaemia in postmenopausal women with osteoporosis appears to be higher in real-life clinical settings than what is reported in clinical trials. However, a protocol that requires assessment and replacement of vitamin D, calcium and creatinine levels in all patients prescribed denosumab lowers the incidence, according to a study presented at the 6th Asia-Pacific Osteoporosis Meeting (IOF Regionals 2016) in Singapore.
Researchers retrospectively examined 52 consecutive postmenopausal women (mean age 75.8 years) with osteoporosis who received denosumab at a 60 mg dose. Biochemical hypocalcaemia was identified as albumin-corrected serum calcium level of ≤2.09 mmol/L. Logistic regression analysis facilitated the evaluation of characteristics associated with denosumab-related hypocalcaemia.
The mean levels of corrected serum calcium, eGFR and 25(OH)D prior to denosumab administration were 2.26 mmol/L, 69 ml/min/m2 and 30 ng/ml, respectively. Additionally, all women were taking 360 mg of elemental calcium and 400 IU of vitamin D pre-denosumab.
Hypocalcaemia occurred in 19.2 percent of women after the first denosumab dose. This event had no significant association with any particular clinical or biochemical feature. All hypocalcaemic patients were asymptomatic, and no one required hospitalization.
Furthermore, 86.53 percent received a second dose of denosumab 6 months after administration of the first dose.
Prior to receipt of the second dose, women with 25(OH)D levels of <20 ng/ml were given 2,000 IU/day of cholecalciferol or 50,000 IU/week of ergocalciferol for 8 to 10 weeks. On the other hand, those with levels of 20 to 30 ng/ml were given similar doses for 4 to 6 weeks. Elemental calcium supplements of up to 1,200 mg/day were administered depending of corrected calcium levels.
Of the women who received the second denosumab dose, only 4.4 percent became hypocalcaemic. Hypocalcaemia did not re-occur in women who had become hypocalcaemic after the first denosumab dose.“Though no particular clinical or biochemical characteristic could predict the development of hypocalcaemia in our cohort of post-menopausal women receiving denosumab for osteoporosis, the dramatic decrease in hypocalcaemia incidence after the second dose can be attributed to the interim institution of the protocolized pre-injection vitamin D and calcium replacement,” researchers noted.