Bisphosphonates (BPs) are the first-line treatment for osteoporosis and are prescribed to the majority of patients with this disease. However, worldwide concern among osteoporosis practitioners is the lack of initiation and adherence to this class of drugs. One of the reasons for this is the most common side effect that occurs when taking this group of drugs – acute phase reaction (APR), or influenza-like syndrome. The article presents the results of scientific studies and meta-analyses aimed at assessing the clinical characteristics of this side effect, its prevalence, as well as those factors that may influence the reduction of its frequency and severity. The data obtained during the studies must be taken into account in clinical practice when prescribing drugs of this group, which will help increase adherence to treatment and achieve a reduction in the number of osteoporotic fractures.

Keywords: acute phase reaction, osteoporotic fracture, vitamin D, bisphosphonates, osteoporosis