What is known and objective Opioid use in the United States has reached unprecedented—some would even say crisis—levels. Although many individuals use opioid drugs as part of legitimate pain management plans, a significant number misuse prescription or illicit opioids. With regular opioid use, individuals develop tolerance and physical dependence; both are predictable, physiologic responses to repeated opioid exposure. However, a substantial number of individuals who misuse opioids will develop opioid use disorder (OUD), a complex, primary, chronic, neurobiological disease rooted in genetic, environmental and psychosocial factors. This article discusses OUD, opioid receptor physiology, and opioid withdrawal symptomatology and pathophysiology, as well as current treatment options available to reduce opioid withdrawal symptoms in individuals with physical dependence and/or OUD. Methods The research articles regarding OUD and its management have been reviewed thoroughly based on a PubMed literature search using keywords related to opioid dependence, its pathophysiology and current treatment strategies. Results and discussion Tolerance/physical dependence and the behavioural characteristics associated with OUD reflect complex neurobiologic adaptations in several major systems of the brain, including the locus ceruleus and mesolimbic systems. Physical dependence is responsible for the distressing withdrawal symptoms individuals experience upon abrupt cessation or rapid dose reduction of exogenous opioids. Opioid withdrawal symptoms are a key driver behind continued opioid use, and a barrier to opioid discontinuation. Several opioid‐based medications are available to treat patients with OUD; these treatments can diminish opioid withdrawal symptoms and cravings as well as block opioid effects in the event of relapse. Additionally, non‐opioid drugs may be used during acute detoxification to help alleviate opioid withdrawal symptoms. What is new and conclusion The opioid crisis has produced many challenges for physicians, one being the need to determine which patients would benefit most from maintenance therapy and which may be candidates for opioid discontinuation. In addition to summarizing current understanding of OUD, we provide a new algorithm for determining the need for continued opioid use as well as examples of situations where management of opioid withdrawal symptoms is indicated.

The purpose of the present Perspectives is to present a synopsis of the literature on bacterial “quorum sensing” as a background for the proposal that interference with this communication system offers potential targets for the design of novel antibiotic drugs. Quorum sensing is the recently discovered chemical communication system among bacteria (both Gram-positive and -negative). It is vital for intra- and interbacterial gene regulation and for keeping bacterial colonies (“biofilms”) intact, allowing resident bacteria to assume specialized roles that contribute to enhanced survival of the group. There are several processes involved in quorum sensing that are familiar to pharmacologists; i.e., specific signaling molecules bind to and activate receptors that transduce the quorum-sensing signal into intracellular second messenger responses. We highlight herein the similarity between quorum-sensing communication to ligand-receptor interactions, suggesting that inhibitor drugs could be designed using current standard pharmacologic principles. Such drugs would have novel mechanisms of action and might therefore be more effective against antibiotic-resistant strains of bacteria.