Poisoned patients who present to the emergency department often require a period of observation to determine their ultimate disposition. Most poisoned patients are able to be discharged within 24 hours, which makes them good candidates for observation unit (OU) admission. Data suggests that clinicians using well-defined protocols can safely manage poisoned patients in the OU. Benefits of OU care for this patient population include earlier involvement of multidisciplinary teams, shorter length of stay, conservation of resources and potential cost-savings. Pediatric poisoned patients in particular are excellent candidates for OU protocols. Multiple agents have been managed in the OU, such as acetaminophen, benzodiazepine, carbon monoxide, stimulants, opioids and various envenomations. OU protocols are not limited to single agent ingestions. OUs may also be used for buprenorphine initiation for the opioid addicted patient. The most effective protocols utilize the expertise of medical toxicologists to help risk stratify appropriate patients for OU care. With well-designed protocols, the poisoned patient can be effectively and safely managed in the ED OU.

Chronic pain can be categorised as nociceptive, neuropathic or nociplastic based on the underlying pathophysiology. It is considered a disease in its own right and can be sub-classified to differentiate types of chronic pain syndromes. Chronic primary pain is defined as pain in one or more anatomical regions, persisting or recurring for more than 3 months, and associated with significant emotional distress or interference with activities of daily life e.g. fibromyalgia or complex regional pain syndrome. Chronic secondary pain includes six subgroups where pain has initially developed as a symptom of another disorder or disease process e.g. chronic cancer-related pain and chronic neuropathic pain.

The experience of pain is a consequence of a variety of biological, psychological, and social factors and a wide range of pharmacological and non-pharmacological interventions are available. Pharmacological management involves opioid agents and non-opioid medications including simple analgesics, topical lidocaine, and capsaicin, anti-epilepsy drugs and antidepressants. Tolerance to opioids can develop rapidly. Misuse and abuse are increasing concerns. Non-pharmacological interventions include psychological and physical therapies. Patient engagement in the process is key and an interdisciplinary approach is recommended which focusses on the individual patient and uses a shared-decision model.

Over the past two decades, the emergency department (ED) has seen an increase in opioid use-related admissions. The ED serves at the frontline of addressing the morbidity and mortality associated with opioid use disorder (OUD). Therefore, it has become a growing consensus that the ED should implement strategies that address OUD and optimize patient outcomes. As such, the observation unit (OU) in the ED has been shown to be an effective site for the observation and management of opioid withdrawal, as well as initiate medication-assisted therapy (MAT). Patients are offered up to 72 hours of MAT doses but are connected to outpatient facilities for long-term management. This initiation in the ED is shown to be more effective in the long-term management of OUD versus referral only. As we continue to manage OUD in the ED, more studies are necessary to establish a standard dosage for buprenorphine therapy, and standardize and solidify MAT initiation in the ED.

Substance use disorders are a major risk factor for maternal mortality, and opioid overdose is a leading cause of maternal mortality in several states. Pregnant and postpartum patients should be assessed for substance use disorders using a validated screening tool, and if present, should be managed with counseling, initiation of pharmacotherapy, and referral for ongoing treatment. Acute presentations of opioid intoxication and opioid withdrawal should be identified and treated. The recommended treatment of opioid use disorder in pregnancy is pharmacotherapy using an opioid agonist. Either buprenorphine or methadone may be appropriate, depending on patient preferences and available treatment resources. Patients should receive education on recognition and prevention of opioid overdose and a prescription for naloxone for overdose reversal.

Stimulants like cocaine, amphetamines, and ecstasy produce short-term desirable effects like alertness, euphoria, and energy. However, they can also cause short- and long-term harm, leading to addiction, dependence, and withdrawal syndrome. Sedative drugs like cannabis, opioids, and benzodiazepines create feelings of calmness and relaxation but can be dangerous in overdose, particularly if mixed with other sedatives. Repeated use of sedatives can lead to severe dependence. Cannabis is the most commonly used illegal drug and can cause paranoia, psychosis, memory problems, and mood disorders with long-term heavy use. Synthetic cannabinoids like ‘spice’ are stronger and more harmful than natural cannabis. Hallucinogens like LSD cause distortions, hallucinations, confusion, and disorientation. They don’t cause dependence but can damage the brain with repeated use. Dissociative drugs like nitrous oxide and ketamine cause disorientation, perceptual disturbances, and loss of physical coordination, leading to accidental injury. Long-term use of ketamine can damage the bladder, and nitrous oxide can cause memory problems and severe nerve damage.

The fact that opioids constrict the pupil is known to healthcare workers and the lay public. In this chapter, the mechanism of this effect is discussed and how an understanding of this mechanism can be useful to the clinician. There are many parameters that can be measured from the pupil with portable pupillometers. The measure that most closely predicts the onset of severe respiratory depression is pupillary unrest in ambient light (PUAL). This measure is compared to pupil size and pupillary constriction amplitude as a measure of toxic levels of opioids.

Trained in addictions in Edinburgh, perhaps an easier specialty given personal experience. Then obtained a consultant post in the Scottish Borders, and a year later one in Edinburgh.

Managing oral pain is a daily task for dental practitioners. Understanding the type of pain, accurately diagnosing the cause and being able to choose the most appropriate drug regimen (if required) is a fundamental skill for all dentists. This chapter describes the medicines commonly used for pain management in dentistry, their mechanism of action, appropriate doses, adverse effects, common drug interactions and their place in therapy.

A class of analgesics structurally similar to the natural alkaloids derived from the resin of the opium poppy. Natural alkaloids are known as opiates and they include morphine and other similarly structured drugs, such as codeine, hydrocodone, and oxycodone. Synthetic derivates include hydromorphone, fentanyl, and heroin, among others (3). Three opiate receptors – µ, ?, and d – were found predominantly in the CNS. Most analgesic effect of opioids is mediated by the µ receptor. Decrease presynaptic calcium influx and increase postsynaptic potassium efflux, leading to inhibition of neuronal firing and neurotransmitter release.

Sickle cell crisis is a term used to capture myriad acute manifestations of sickle cell disease (SCD). Underlying pathophysiology is due to polymerization of HbS, sickling of erythrocytes, and microvascular occlusion and injury. Sickle cell disease and related pain is common in the US, especially among black Americans. Routine newborn screening picks up the majority of cases and helps guide prevention and treatment of acute pain crises early on. The mainstay of treating vaso-occlusive crises is analgesia and is often achieved with NSAIDs, opioids, or combination therapy.

Pain is quite common in patients with cancer, especially those with metastaticdisease. Oncologic pain implications: decreased quality of life, can be an indicator of the progression of a tumor, and psychosocial effects such as anxiety and depression. Cancer pain is divided into acute form and chronic form. Advances have been made in both oncology and pain management. The application of pain management into clinical oncology is still a work in progress. Pain management that is sufficient and consistent is difficult in cancer patients. Cancer pain affects a large portion of those with cancerous disease processes. Metastatic disease tends to be associated with more pain. Pain can come from the cancer itself or from the treatment. More work is needed to standardize the evaluation and treatment of cancer pain. Further work is needed to take into account each individual’s unique circumstance.

Chapter 8 contains an in-depth case study of the opioid mass tort litigation in federal and state courts. It describes the inception and development of the opioid drug crisis and how the opioid crisis affected state and local municipalities, in requiring additional expenditures of money to provide medical, policing, and various social services to communities affected by the crisis. The chapter describes the initiation of opiod litigation, the hundreds of lawsuit, consolidation and transfer of all the opioid litigation into a federal MDL under Judge Dan Polsters supervision in the Northern District of Ohio. The chapter chronicles the management and litigation in the federal MDL proceedings and Judge Polsters approval of a public nuisance claim which actually went to trial. The chapter narrates the resulting, cascading opioid settlements with opioid manufacturers, distributors, and pharmacies concurrent with and after the MDL bellwether public nuisance trial. The chapter further chronicles the fate of opioid public nuisance in state courts, with a notable rejection of a public nuisance claim by the Oklahoma Supreme Court. The chapter ends by documenting the many state court opioid settlements during 2021-2022.

Methadone, a medication used to treat opioid use disorder (OUD), has resulted in decreased opioid overdose deaths, while increasing treatment retention and lowering the rates of infectious diseases associated with intravenous substance use. Access to methadone is limited in the United States due to federal laws and regulatory policies that are rooted in racist “criminal justice approaches” to substance use. Unlike other controlled prescription medications, methadone is subject to restrictions on the number of doses a person can receive at any given time, known as “take-home doses” (THDs). Federal regulations mandate that patients receiving methadone must travel to government-certified clinics known as opioid treatment programs (OTPs) almost daily to receive medication for at least the first 90 days of treatment. Due to the need to practice social distancing during COVID-19, the Substance Abuse and Mental Health Services Administration (SAMHSA) – the regulatory agency which sets the accreditation standards for OTPs – released a federal waiver in March 2020 granting significant exemptions to THD regulations. Thousands of patients have now received increased THDs, a historic and impactful shift in care for people with OUD. This chapter begins with an overview of the regulation of methadone for OUD before COVID-19. Next, it reviews the evidence for regulatory reform alongside our analysis of qualitative data we collected during COVID-19 that reflects patients’ experiences with increased access to THDs. Based on the findings of our qualitative study and the empirical literature, we conclude the chapter with recommendations for modifications of THD regulations.