Treating acute pain in opioid-experienced patients

Learn best practices for managing acute pain in patients with opioid use disorder, on chronic opioid therapy, and on opioid-agonist therapy.

Managing acute pain in the hospital is often tricky business, but some patients' pain can be more difficult to treat than others. Theresa Vettese, MD, FACP, offered best practices for managing acute pain in three challenging groups of hospitalized patients during a session at Hospital Medicine 2018.

Patients with opioid use disorder

People who are addicted to opioids have decreased pain tolerance and higher tolerance to opioids, and withdrawal makes pain worse, Dr. Vettese noted. Although concern about inappropriate use often makes clinicians anxious about prescribing opioids to these patients, do not be afraid to use the drugs to treat their acute pain, she advised.

“It's important for all of us to remember that untreated acute severe pain is a bigger trigger for worsening addiction or relapse than using opioids for analgesia,” said Dr. Vettese, an associate professor in the division of general medicine and geriatrics at Emory University School of Medicine in Atlanta.

Dr Vettese
Dr. Vettese

Of course, communication is key. “Upfront, I tell patients who have opioid use disorder, ‘I want to talk about your pain. I want to talk about what our goals are,’” she said.

The goal is not to be entirely pain-free. “It's just not going to happen,” said Dr. Vettese. “The goal is to get you to be able to take care of yourself when you leave the hospital.” Getting up, going to the bathroom, sleeping for a few hours, and taking a shower should be the goals of pain management in these patients, she said.

To guide treatment, it's important to figure out how much heroin (or other opioids) the patient is using, she said. “I usually start out by saying, ‘Listen, I'm not going to be judgmental. I'm here to treat your pain...[and] it's really important for you to be honest with me and tell me how much heroin you're using,’” Dr. Vettese said.

Most patients will open up, providing information about the number of milligrams or “bags” of heroin they use daily, she said, noting that the average heroin user takes about five bags a day. A bag of heroin is 100 mg of IV heroin and is about 40% pure on average, depending on where the drug is from, said Dr. Vettese.

“If you take into account the fact that milligrams of heroin actually refers to the weight of the heroin...100 mg of IV heroin is about equivalent to 15 to 30 mg of IV morphine,” she said. “I usually use the lower number to account for the fact that people react differently to different opioids.”

For someone using five bags of heroin per day, that translates to 75 mg of IV morphine over a 24-hour period. “If you're going to use short-acting, immediate-release opioids, that's 10 mg IV [every] three hours, either [when necessary] or with right of refusal, or both if the patient is too sedated,” said Dr. Vettese. Patient-controlled analgesia is also an option and is less associated with respiratory depression, she added.

When giving IV heroin users IV opioids, it's important to reassess them quickly, as “They often will need higher doses and even [shorter] frequency than what you started them on,” Dr. Vettese said. At the beginning of pain treatment, outline the plan with patients and assure them that their pain will improve, she advised.

That explanation could be something like this: “I'm going to use IV [opioids] initially to get your pain under control and your withdrawal under control, but as soon as possible—in the next 24 hours, hopefully—we're going to switch you to oral, and then we're going to begin a taper,” she said. It's also important to prescribe—and emphasize the effectiveness of—nonopioid and nonpharmacological treatments such as NSAIDs, antibiotics, and physical therapy, she said.

The ideal length of an opioid taper is 10 to 14 days because that's how long acute withdrawal symptoms last, Dr. Vettese said. “If you don't have time, you can do it in a shorter time period, but it's going to be associated with greater risk of relapse,” she said.

At discharge, physicians should consider referring patients to addiction treatment if appropriate and/or applying harm-reduction strategies, such as prescribing naloxone (and calling the pharmacy beforehand to ensure it's available), screening for HIV and hepatitis C virus, and directing patients to needle/syringe exchange programs, she said.

Patients on chronic opioid therapy

Despite the well-known epidemic and resulting push to reduce opioid prescriptions, Dr. Vettese said she still sees patients with chronic pain “who are on higher doses and will be on higher doses probably forever.” When she sees patients who are on chronic opioid therapy, the first thing she does is check the state's prescription drug monitoring program (PDMP) database and contact the patient's primary care doctor.

“The PDMP, even in the hospital setting, gives you a wealth of knowledge, and you just uncover things that you would never expect,” she said. If the patient is getting opioids from one prescriber, filling them regularly, and using them responsibly, continue that dose, Dr. Vettese said.

These patients require an honest conversation at admission, she said. “I tell them, ‘Listen, here's this deal: I know that your pain is worse. Any time someone has an acute illness, it's going to be worse. We're going to use the opioid pain medications that your primary care doctor's prescribing you. On top of that, we're going to use nonopioid and nonpharmacological treatments.”

There are many pain-management tools in the nonopioid toolbox, but some are more effective than others. She noted that many anesthesiologists like to use single-dose oral gabapentin postoperatively, but a 2010 Cochrane review found only a modest improvement in postoperative pain, with a number needed to treat (NNT) of 11 to improve pain by 50% compared to placebo.

“If you're a cardiologist, a NNT of 11 is fabulous; if you're a pain doctor, it's really a very modest effect....My verdict is that it's not a great pain reliever but worth a try, particularly in people who are already on chronic opioids, have opioid use disorder, or are opioid dependent,” said Dr. Vettese.

NSAIDs (NNT=3) or acetaminophen (NNT=5) are better options for nonopioid management of postoperative pain, she said, noting that IV and oral acetaminophen have the same NNT but that IV is exponentially more expensive than oral. “One of the things that might surprise people is how effective acetaminophen is...[but] everybody gets NSAIDs if they can,” said Dr. Vettese. For painful rib fractures, 5% transdermal lidocaine patches are both inexpensive and effective adjuncts to opioids, she added.

Last, it's important to tell patients that they will not receive opioid medications at discharge, Dr. Vettese said. A 2016 study published in JAMA Internal Medicine found that 14.9% of Medicare patients were discharged on opioid therapy, and 42.5% of them were still receiving opioids 90 days later.

“We are part of the issue, but yet we're also the people who are responsible for managing acute and severe pain....I tell people, ‘You will not get [opioid] pain medications from me at discharge. If you don't have them, you need to call your primary care physician now and make a discharge appointment so you can get a refill,’” said Dr. Vettese.

Patients on opioid-agonist therapy for opioid use disorder

Patients who are on opioid-agonist therapy (e.g., buprenorphine and methadone) for opioid use disorder are “becoming more and more frequent” in the hospital setting, Dr. Vettese said. When these patients present with acute pain, be sure to contact the prescribing clinician at admission to verify their dosage, as well as at discharge, Dr. Vettese recommended.

Methadone and buprenorphine are dosed every 24 to 48 hours and therefore do not confer analgesia, she noted. Clinicians have several options to manage pain in these patients, who are often very nervous about using opioid pain medications, Dr. Vettese said. “And we also feel that way: I don't want to lead to the relapse.”

But since untreated acute pain causes more adverse outcomes in people with opioid use disorder, whether or not they are treated, sometimes opioids are part of the solution, she said. “That's why I tell patients, ‘We'll use this in a limited fashion, but we need to control your pain, and nonpharmacological treatments are always part of the plan.’”

If a patient is on buprenorphine, it's possible to continue the maintenance dose and start another opioid agonist on top of it because buprenorphine is only a partial agonist, Dr. Vettese said, noting the common misconception that this does not work. “Opioid agonists that have a close affinity to the mu-opioid receptor will bump off the buprenorphine, providing analgesia.”

However, a better option may be to simply split the daily dose of the maintenance opioid as part of the analgesic program, using short-acting opioid agonists if necessary, Dr. Vettese said. Dosing buprenorphine or methadone every six or eight hours produces an analgesic effect and can “hopefully decrease the short-acting, immediate-release opioids that a patient needs,” she said.

Again, taper and discontinue any full opioid analgesics as the patient's acute pain resolves. “They will want it [to discontinue]. People who are successfully treated and have been on opioid-agonist therapy for a while, they are usually very motivated,” Dr. Vettese said.