Opioid use is increasing worldwide leading to an increasing amount of opioid-tolerant patients who may require acute pain management. Pain in this patient population is often poorly understood and therefore may be inadequately treated. The main goals in treating acute pain in opioid-tolerant patients are providing effective pain relief and minimizing withdrawal symptoms. Other challenges include assisting with social issues, poor coping, and psychiatric issues. This chapter discusses important factors to consider when treating acute pain in opioid-dependent patients.
Tolerance is a physiologic adaptation in which increasing amount of a drug is required to achieve the same pharmacologic effects after prolonged use. Tolerance develops to most effects of opioids, including analgesia, euphoria, sedation, respiratory depression, and nausea; however, tolerance does not develop to miosis or constipation.1
Withdrawal refers to physiologic symptoms resulting from the abrupt discontinuation of chronically administered opioids. Although withdrawal from opioids is rarely life threatening, it can be very uncomfortable. The symptoms of opioid withdrawal include abdominal cramps, anxiety, diarrhea, disturbed sleep, irritability, dysphoria, nausea and vomiting, rhinorrhea, urinary frequency, twitching, lacrimation, and increased muscle spasms.
The symptoms of opioid withdrawal include abdominal cramps, anxiety, diarrhea, disturbed sleep, irritability, dysphoria, nausea and vomiting, rhinorrhea, urinary frequency, twitching, lacrimation, and increased muscle spasms.
The onset and time course of opioid withdrawal are determined by the half-life of the drug (Figure 54–1). Withdrawal symptoms of short-acting opioids such as heroin and morphine typically begin more rapidly than long-acting agonist opioids such as methadone. Symptoms of withdrawal with short-acting opioids start 6–24 hours after the last dose, peak at 24–48 hours, and resolve within 5–10 days. Methadone is a long-acting opioid agonist; its withdrawal symptoms emerge 36–48 hours after the last dose. Some low-grade symptoms of withdrawal may linger for 3–6 weeks after last use due to its long half-life.2
Symptoms and duration of heroin and methadone withdrawal.
Withdrawal symptoms may develop in opioid-tolerant patients if their usual dose of opioids is stopped, reduced too quickly, or the effect of the opioid is reversed by an antagonist such as naloxone.
Withdrawal symptoms can occur even with small decreases (10%–15%) in opioid dosing and can manifest as myalgias and arthralgias in addition to return of the pain.
Substance Abuse and Dependence
Before the release of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders in 2013, substance abuse and dependence were considered two separate disorders. They are now considered to be a single disorder measured on a continuum from mild to severe. Substance abuse and dependence are now recognized as the recurrent maladaptive ...