Background Intravenous-bisphosphonates (IVB) are effective and very widely used in treatment of osteoporosis. Prior inadequate serum 25 hydroxyvitamin-D (25OHD), before administering IVB could lead to rapid life-threatening hypocalcaemia1,2. Also, it is well known that to achieve optimal benefit of IVB adequate levels of vitamin-D are needed3.
Objectives We share our experience regarding exploration of checking vitamin-D status pre-administration of IVB in patients with osteoporosis.
Methods In this retrospective observational study, the electronic records of 408 patients with osteoporosis, attending a planned-short-stay-unit (PSSU) for IVB (i.e. zoledronate, pamidronate and ibandronate) in year 2009 were searched. 114 out of 408 patients were excluded due to incompletely recorded data; hence, data-set on rest 294 patients was retrieved which was exported to excel sheets and analysed regarding type of bisphosphonates, pre-bisphosphonate vitamin D level status and the referring speciality.
Results These 294 patients attended PSSU for 636 infusions over a period of one-year; where 112/294 (38%) had annual zoledronate, 52/294 (18%) had 6-monthly pamidronate and 130/294 (44%) had 3-monthly ibandronate leading to 112, 129 and 395 infusions respectively. These 636 infusions were requested by various specialities; where majority 431/636 (68%) were from metabolic-bone-clinic, 129/636 (20%) from rheumatology and 64/636 (10%) from gastroenterology, whereas only 12/636 (2%) were referred from combined geriatrics, endocrinology, general-medicine and nephrology units.
In zoledronate group pre-IVB vitamin-D status were assessed in 102/112 (91%) patients; where majority patients i.e. 97/102 (95%) were replete and the remaining 5/102 (5%) were thereby administered vitamin-D. However, amongst the pamidronate group vitamin-D status was checked only in 67/395 (17%) pre-IVB infusion episodes; where 42/67 (63%) were replete. Furthermore, amongst ibandronate group repletion such status was checked only in 25/129 (19%) infusions, where 9/25 (36%) were vitamin-D replete.
Conclusions Overall, in less than one-third (194/636) infusions pre-IVB vitamin-D status was checked and only 23% were vitamin-D replete pre-IVB. Amongst the rest, in just over two-third infusions (442/636) vitamin-D levels were not examined at all. This retrospective analysis illustrates, that there is further scope for improvement in checking vitamin D repletion status prior to administering IVB, especially in pamidronate and in bandronate group. Perhaps, this is of utmost important amongst zoledronate group, where life-threatening hypocalcaemia have been previously reported1,2.
Rosen CJ, Brown S. Sever hypocalcaemia after intravenous bisphosphoinate therapy in occult vitamin D deficiency. New Engl J med 2003;348:1503-4.
Pete R, Mishra V, Fraser WD. Sever hypocalcaemia after being given intravenous bisphosphonates. Br Med J 2004;328:335-6.
Novartis. Zometa (Zoledronic acid) injection prescribing information. East Hanover, NJ;2005 Apr.
Disclosure of Interest None Declared