1. Timing of new black box warnings and withdrawals for prescription medications;Lasser;J Am Med Assn,2002
2. Food and Drug Administration (FDA) Risk evaluation and mitigation strategy (REMS) for extended-release and long-acting opioids http://www.fda.gov/drugs/drugsafety/informationbydrugclass/ucm163647.htm
3. European Medicines Agency (EMEA) European medicines agency recommends withdrawal of dextropropoxyphene-containing medicines http://www.ema.europa.eu/ema/index.jsp?curl=pages/news_and_events/news/2009/11/news_detail_000074.jsp&mid=WC0b01ac058004d5c1
4. European Medicines Agency (EMEA) European medicines agency recommends withdrawal of dextropropoxyphene-containing medicines http://www.ema.europa.eu/docs/en_GB/document_library/Press_release/2009/11/WC500010365.pdf
5. Food and Drug Administration (FDA) FDA MedWatch http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm234389.htm