Abuse liability of centrally acting non-opioid analgesics and muscle relaxants--a brief update based on a comparison of pharmacovigilance data and evidence from the literature.

There is a lack of data regarding the abuse liability of centrally acting non-opioid analgesics (NOA) and muscle relaxants (MR). A comparison of data retrieved from a German pharmacovigilance database (BfArM; accessed May 2013) and data from the literature concerning the abuse liability of NOA and MR approved in Germany was performed. The BfArM-database demonstrated cases of abuse only for clonidine and paracetamol, whereas the literature suggests evidence for an abuse potential of baclofen, clonidine, ketamine, metamizole, methocarbamol, orphenadrine, paracetamol, propyphenazone, and tizanidine. The low number of detected cases in the BfArM-database could be a result of under-reporting.

Drug safety and adverse drug reaction reporting behavior related to outpatient opioid replacement therapy: Results from a survey among physicians.

To study drug safety and the reporting behavior of adverse drug reactions (ADR) related to agents used for opioid replacement therapy (ORT) we conducted a cross-sectional questionnaire-based telephone survey among physicians who provide outpatient ORT in Germany (n=176; response rate=55.7%). Most respondents (n=97/55.1%) reported that they observe ADR related to buprenorphine, (dihydro)codeine, and (levo)methdone rarely (n=38/21.6%), very rarely (n=39/22.2%) or never (n=20/11.4%). Methadone was reported to be most frequently associated with the occurrence of ADR (n=82/46.6%), followed by levomethadone (n=33/18.8%), buprenorphine (n=6/3.4%), and dihydrocodeine (n=3/1.7%). Frequently observed ADR related to these agents were gastrointestinal, nervous system/psychiatric disorders, and hyperhidrosis. Methadone and levomethadone (not buprenorphine) were frequently associated with fatigue, weight gain, and sexual dysfunction. Hundred twenty nine participants (73.3%) stated that they never report ADR related to ORT; n=19 (10.8%) did so when referring to ADR related to their complete medical practice (X2=141.070; df=1; p<0.001). Similar patterns of ADR related to outpatient ORT as those reported in the product information or in pain therapy were found. Motivation to report ADR related to ORT may be reduced compared to ADR related to the general medical practice.