A randomized controlled trial to assess the effect of a three day course of dexamethasone on the incidence of the acute phase response following treatment with zoledronic acid

Research question The study aimed to determine whether the daily temperature readings of patients receiving zoledronate would be improved by providing a three-day course of oral dexamethasone starting at the time of zoledronate infusion, compared with placebo. It also aimed to assess whether there was a difference in symptoms of the acute phase response between participants receiving dexamethasone compared with placebo. Background information Zoledronate is a medication which is effective in the treatment of osteoporosis, Paget’s disease, and hypercalcemia of malignancy. However, treatment with zoledronate can cause a reaction in some patients known as the acute phase response. The acute phase response is an inflammatory process that can occur after a zoledronate infusion which causes symptoms including fever, joint pain and swelling, muscle pain and nausea. About 40% of patients experience the acute phase response after the receiving zoledronate for the first time. Glucocorticoids are known to reduce inflammation through multiple pathways. Participant characteristics There were 60 participants enrolled in the study. The average age in the dexamethasone group was 78 years and in the placebo group was 76.5 years. One participant was Maori (1.7%), three participants were of Asian ethnicity (5%), and 56 participants were of New Zealand European ethnicity (93.3%). Baseline temperature was 36.4 degrees in the dexamethasone group and 36.2 degrees in the placebo group. Key results There was a difference in the change in temperature from baseline between the dexamethasone and placebo groups, which was greatest at bedtime the day after treatment when there was an average decrease of 0.10 degrees from baseline in the dexamethasone group compared with an average rise in temperature of 0.84 degrees from baseline in the placebo group. There was also a difference in change in symptom score over time between the two groups, which was greatest one day following treatment, where there was a median change in symptom score of 0 in the dexamethasone group compared with 3 in the placebo group. Limitations Glucocorticoids can affect bone density when they are taken long-term. Given this is a very short course of dexamethasone, there is unlikely to be a substantial detrimental effect on bone. Limitations include use of symptom scores which is a subjective measurement, and reliance on recordings of temperatures at home being taken accurately using the thermometers provided.