Drugs that can cause respiratory depression with concomitant use of opioids.

Aims Respiratory depression is a serious life threatening condition and a known adverse event of opioids. Little is known about the use of the opioid antidote naloxon in Iceland, and the additive effects of other potentially respiratory depressive drugs administered with opioids. The aim of the study was to review the literature on drugs that may cause respiratory depression and to assess medication use in patients receiving parenteral naloxone in Landspítali University Hospital. Methods A review and analysis of drugs that can cause respiratory depression based on information from the scientific literature, medicine databases and clinical guidelines. A retrospective study was performed using data collected from the electronic medical records system of Landspítali University Hospital for all patients, 18 years and older that had parenteral naloxon administered in the years 2010-2014. Information about the type of opioid and other respiratory depressive drugs was collected and the data was further investigated in regards to age, gender, and type of service. Results The most potential drugs and drug classes that can cause respiratory depression when used concomitantly with opioids are benzodiazepines and other anxiolytics, hypnotics and sedatives, antipsychotics, antiepileptics, antihistamins and anesthetics. When use was examined (N=138) morphine was the most frequent opioid given (49%). Concomitant use of opioids and other respiratory depressive drugs was seen in 63% of cases, and benzodiazepines were the most frequent drugs given with opioids (33%). Conclusions The concomitant use of benzodiazepines and other sedative drugs with opioids is frequent, despite the known risk of additive respiratory depression as described in the literature. Other patient risk factors such as medical condition, general health and consciousness should be considered in context with drugs used.