Opioid withdrawal syndrome: Clinical sciences

Opioid withdrawal syndrome refers to signs and symptoms that occur after abrupt cessation or dose reduction in individuals who are physically dependent on opioids. The terms opiates and opioids are sometimes used interchangeably, but they actually refer to different entities. Opiates refer to only naturally occurring compounds derived from the poppy plant like heroin, morphine, and codeine, all of which have agonistic effects on the opioid receptor. On the flip side, opioids include synthetic and semisynthetic compounds that resemble opiates in structure and their effects on the opioid receptor.

While opioid withdrawal syndrome is not usually life-threatening per se, it can cause significant distress and discomfort, has the potential to cause complications in individuals with chronic conditions, and can significantly interfere with patients receiving care for a medical illness, potentially causing fatalities that way. Now, based on the severity, opioid withdrawal syndrome can be classified as mild, moderate, or severe.

Of note, it’s a common misconception that patients experiencing opioid withdrawal must have an opioid use disorder. Moreover, opioid withdrawal can occur in anyone who develops physical dependence on opioids, which occurs at the cellular level and can happen even after two to three weeks. This means that patients who are taking appropriate doses of opioids as prescribed for medical indications could also experience opioid withdrawal syndrome! Finally, you should anticipate opioid withdrawal syndrome in an opioid-dependent individual who receives an opioid antagonist, like naloxone or naltrexone.

Now, if your patient presents with chief concerns suggesting opioid withdrawal syndrome, first, you should perform an ABCDE assessment to determine whether they’re unstable or stable. If unstable, stabilize the airway, breathing, and circulation, which might require endotracheal intubation and mechanical ventilation. Next, obtain IV access and put your patient on continuous vital sign monitoring, including blood pressure, heart rate, pulse oximetry, and cardiac telemetry. Finally, if needed, don’t forget to provide supplemental oxygen!

Alright, now that we’ve addressed unstable patients, let’s go back to the ABCDE assessment and discuss stable ones. If your patient is stable, perform a focused history and physical examination. Your patient will likely report recent opioid cessation or dose reduction with the development of gastrointestinal symptoms, like nausea, vomiting, and diarrhea and musculoskeletal symptoms, such as body aches and muscle cramps. Additionally, your patient will often report psychological symptoms, including insomnia and depression, and autonomic symptoms, like watery eyes, runny nose, chills, and yawning. There might also be a history of acute or chronic pain, or substance use disorder.

Next, physical examination will reveal signs of sympathetic overactivity, such as tachycardia, elevated blood pressure, elevated body temperature, sweating, and irritability. Finally, sympathetic overactivity often results in mydriasis and piloerection. With these findings, you can diagnose opioid withdrawal syndrome.

Here’s a clinical pearl! Opioid withdrawal symptoms typically start within 12 to 24 hours of stopping an opioid. However, the onset of symptoms depends on the formulation taken. For example, long-acting or extended-release opioids might take up to 48 hours to induce withdrawal symptoms! Moreover, symptoms can persist for a few days to several weeks depending on the dose and duration of opioid use.

Okay, your next step is to assess the severity of withdrawal using a validated metric, such as the clinical opiate withdrawal scale, or COWS for short. COWS rates common signs and symptoms of opioid withdrawal, including resting pulse rate, pupil size, sweating, restlessness, yawning, bone or joint aches, runny nose or tearing, GI upset, tremor, anxiety or irritability, and goosebumps.

Let’s start with mild withdrawal! If your patient has a COWS score below 13 points, they’re experiencing mild opioid withdrawal. In this case, treatment is typically in an outpatient setting. If the plan is for opioid continuation, for example to continue treating chronic pain in a compliant patient that has run out of medication, simply restart the opioid medication. You might also consider starting buprenorphine or methadone in place of the prior opioid as their pain control method. On the other hand, if an opioid use disorder is present, buprenorphine or methadone therapy is most appropriate.

Buprenorphine is a partial opioid receptor agonist with a long half-life, an effective analgesic profile, and a strong affinity for the opioid receptor. Because of these properties, buprenorphine can be considered as an alternative medication option for patients experiencing withdrawal in between doses of the opioid they're taking in a compliant fashion for indications like chronic pain. Moreover, buprenorphine has a lower potential for misuse when treating opioid withdrawal syndrome in an individual with opioid use disorder.