Factors influencing the use of opioids for breakthrough cancer pain: A secondary analysis of the IOPS-MS study

Background: Controversies exist about the choice and the doses of opioid medication in breakthrough cancer pain (BTcP). Methods: The aim was to assess factors influencing the use and the doses of opioids prescribed for BTcP. There was performed a secondary analysis of a national, multicentre study that involving 32 centres performed in patients having BTcP. Diagnosis of BTcP was based on a definite algorithm. Patients using opioids for background pain and for BTcP were selected. Average pain intensity and opioids used for background pain and BTcP, and adverse effects were assessed, as well as patient’s satisfaction and the grade of mucositis. Results: The analysis was performed in 2,771 patients. Opioid doses given for BTcP were significantly associated with those given for background pain. No relationship between adverse effects and the use and the doses of opioids used for BTcP was found. Drugs and doses were not correlated to the grade of oral mucositis. Nasal fentanyl preparations provided the fastest meaningful pain relief in comparison with other fentanyl transmucosal preparations or morphine preparations (P = 0.000). The majority of patients were satisfied with opioid medications given for BTcP. Only 2.8% of patients reported adverse effects related to opioid medication used for BTcP. Age and gender were independently associated with dosages of some fentanyl products. Conclusions: Opioids for BTcP were effective and safe in a large sample of cancer patients with different stages of disease. Doses of opioids proportional to doses used for background pain seem to guarantee both efficacy and safety. Significance: The use of opioids for breakthough cancer pain was effective and safe in a large sample of advanced cancer patients recruited in different stages of disease and settings. Doses of opioids proportional to opioid doses used for background analgesia, seem to guarantee both effectiveness and safety.