Common drug switching during long-term antiresorptive treatment: experience of four osteoporosis centers in Poland (2001–2005)

Background and aims:In clinical trials, the most frequent reasons for treatment discontinuation are adverse events and personal conflicts with medical staff. However, in ‘real life’, i.e. not in the frame of a controlled and monitored trial, other reasons are also possible, when not only discontinuation, but also switching of treatment happens. The aim of this study was to estimate how often and why persistent osteoporosis patients switch from one treatment to another. Methods:A retrospective analysis of 1314 ambulatory treated persistent osteoporosis patients was performed (1180 F, 134 M, mean age±SD: 66.5±10 yrs, BMI 26.4±4.2 kg/m2). Drugs used for osteoporosis, duration of treatment, frequency and reasons for drug switching were all analyzed. Results:In 530 (40.3%) patients, treatment was not changed during the observation period (16.1±9.1 months). In 784 (59.7%) patients at least one drug switch happened, and the total number of switches was 1117 (1–5 switches/patient). The mean time of observation in this group was 22.3±14.9 months. The most frequent reasons for drug switching were: adverse event (34.6% of all switches), high price of the drug (28.7%) and ineffective treatment (13.3%). Conclusions:In almost 60% of the persistent patients, at least one switch of antiosteoporotic treatment occurred in the nearly 2-year observation period. The most frequent reasons for drug switching were adverse reactions, the high price of the drug, and ineffective treatment.