Home Clinical Treating pain in patients maintained on methadone or buprenorphine

Treating pain in patients maintained on methadone or buprenorphine

Hospitalists have many misconceptions about these drugs

March 2009

Behavioral health hospitalist David Frenz, MD, medical director for addiction medicine for the HealthEast Care System in St. Paul, Minn., fields plenty of questions from acute-care colleagues on how to manage acute or chronic pain in patients with substance use disorders. One common question is how to treat pain in patients receiving maintenance therapy with methadone or buprenorphine. It turns out that physicians have a very limited comfort zone with these drugs—and plenty of misconceptions.

That confusion is understandable, Dr. Frenz points out, given the dense regulations governing these drugs’ clinical use. Part of the confusion is due to the fact that different rules govern where and how methadone and buprenorphine may be used and by whom. Another problem: Because sublingual buprenorphine (Suboxone or Subutex) is a newer agent, doctors have limited clinical experience with it.

While both methadone and buprenorphine are powerful analgesics and effective agents for treating opioid addiction, some experts advise against using either drug for both purposes concurrently. That adds to the confusion: What should doctors do for patients on a maintenance opioid agent to provide pain relief?

Administering methadone
When It comes to administering methadone, physicians are worried about getting into regulatory hot water. “A lot of hospitalists are afraid to use methadone because they think they’re ‘not licensed’ to do so, but that’s not the case,” Dr. Frenz says. “Any licensed prescriber may use methadone to treat acute opioid withdrawal syndrome provided they follow some relatively simple federal guidelines.”

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These guidelines make up the so-called “72-hour rule,” which states that methadone may be administered to a patient (but not dispensed or prescribed for unsupervised use) for up to three days. “The intent,” Dr. Frenz explains, “is to relieve suffering while appropriate transfer of care is being made.”

Hospitalist Michael Miller, MD, medical director of the NewStart Alcohol/Drug Treatment Program at Meriter Hospital in Madison, Wis., points out that the rule applies only when opioid addiction is the primary clinical focus, such as when a patient is withdrawing from prescription pain pills or heroin.

The rule does not come into play when methadone-maintained patients are admitted to the hospital for other reasons. Under these circumstances, hospitalists may continue a patient’s methadone indefinitely without running afoul of the law. “You can treat those patients while they’re there, but you can’t give them any methadone on their way out the door,” Dr. Miller says. “All outpatient prescribing of methadone for addiction must be done by a federally licensed methadone clinic.”

As long as patients are being admitted for a medical or psychiatric reason other than drug addiction, “you are A-OK continuing their methadone because you are making no attempt to manage their opioid use disorder,” Dr. Frenz points out. “It’s just like continuing eye drops for glaucoma.”

Methadone maintenance dosing
Methadone dosing, however, is less straightforward. Both Drs. Frenz and Miller suggest confirming patients’ dosing histories with their clinic. Don’t believe patients’ self-reports about the amount of their maintenance dose.

Updated systematic review: literature review of pain management strategies for patients on methodone maintenance therapy

“Some patients who are methadone maintained on a dose of 100 mg per day might tell you it’s 150 mg just to see if they can get you to write for more,” says Dr. Frenz. “Hospitalists would be very wise to call patients’ methadone clinic and verify their dosing history.” Another big reason to call the methadone clinic is to find out when patients had their last maintenance dose. Otherwise, Dr. Miller says, it’s safe to give newly admitted patients only 30 mg of methadone as an Initial dose on the first day.

If the patient has missed three days of maintenance doses, he adds, his clinic would treat the patient at 50% of that dose “and then build them back up.” If the patient has been away from the clinic for a week, the starting dose in the hospital might be 25% of the regular dose.

“You don’t restart them at the dose they were on because their tolerance has gone down,” Dr. Miller says. Patients who’ve missed only one day can be given their regular dose.

Add-on opioid
Managing acute pain syndromes in methadone-maintained patients is a lot like diabetes management

“Methadone or buprenorphine is the equivalent of basal insulin,” explains Dr. Frenz. “Patients need the medication to feel stable and function normally. They will also need an additional opioid “bolus insulin by analogy “to address the acute pain associated with injury or surgery.”

Hospitalists should administer the regular methadone dose for maintenance only, adding another opioid “ideally used in combination with NSAIDs and acetaminophen, to reduce total opioid needs “in high-enough doses to control pain.

Dr. Frenz notes that opioid-tolerant patients will require greater-than-usual doses of a supplemental opioid compared to those who are opioid-naive. “As the doses can be substantial, hospitalists and surgeons should consider consulting with someone familiar with opioid management,” he says. “In our health care system, those consultations are fielded by the palliative medicine and addiction medicine services.”

As long as doses are titrated carefully and patients are monitored, physicians don’t need to worry about putting patients at higher risk for respiratory or central nervous system depression. Studies have shown that patients with addiction or dependence can tolerate the drugs’ depressant effects quickly when higher doses are used for pain control.

And experts say that hospitalists shouldn’t be overly concerned about worsening or rekindling a patient’s addiction. “There’s something funny about acute pain that attenuates the rewarding properties of opioids,” Dr. Frenz explains. “Patients receive analgesia but not euphoria.”

Nor are patients on opioid agonist therapy at significant risk for relapse because they’ve received opioid analgesics for acute pain. Instead, some research suggests that under-treating pain in patients with addiction may pose a greater relapse risk because of the stress associated with that untreated pain.

Buprenorphine dosing
Things get stickier when it comes to buprenorphine. According to Dr. Miller, any physician registered with the Drug Enforcement Agency (DEA) may administer Buprenex, a parenteral form of buprenorphine, for analgesia. (See “Buprenorphine: doses and indications” below.)

However, physicians must obtain a supplemental DEA number, commonly called a “waiver,” to use the sublingual formulations, regardless of the intended purpose “including maintenance. For inpatients on buprenorphine maintenance, Dr. Frenz suggests that hospitalists get a consult from an addiction medicine specialist, who is likely to be waivered, or call their state opioid treatment authority who can suggest some regulatory workarounds.

Even for waivered physicians, buprenorphine maintenance dosing can be tricky because it has to be individualized. initial maintenance dosing, following titration, is typically between 12 mg and 16 mg per day, though some patients never get beyond between 4 mg and 8 mg per day; the dose may be titrated as high as 24 mg per day. Although higher doses have been reported, opioid receptor occupancy is in the 90% range at 24 mg. Patients who require more than 24 or 32 mg per day should be considered for transfer to methadone maintenance.

Add-on dosing for pain control can also be complicated. That’s because buprenorphine occupies the opioid receptors very tightly, Dr. Miller explains.

“It’s hard to get another opioid to work,” he points out. “That has to be taken into account in the treatment plans.”

If the patient is taking less than 32 mg a day, which is considered the “ceiling dose,” hospitalists can safely add more buprenorphine as analgesia. But if the patient takes a higher maintenance dose, Dr. Miller advises physicians to add oral NSAIDs or parenteral ketorolac (Toradol), or to use opioids that work by mechanisms other than occupying the mu opioid receptor.

“Many physicians are using fentanyl or tramodol (Ultram) for analgesia in buprenorphine-treated patients because patients can get an analgesic response,” Dr. Miller explains. Keep in mind that many patients will not get pain relief from morphine or codeine, he adds, because their opioid receptors are fully occupied by buprenorphine.

Treatment guidelines
Experts say that a good starting point for treating pain in patients on buprenorphine maintenance is to follow options outlined in an article in the Jan. 17, 2006, Annals of Internal Medicine. Those options include the following:

For pain of short duration, maintain the buprenorphine maintenance dose and titrate short-acting opioids for the pain, or divide the buprenorphine daily dose into three or four smaller doses to be given every six to eight hours.

For pain of longer duration, discontinue buprenorphine maintenance and administer opioid analgesics as needed. Convert the patient back to buprenorphine maintenance therapy when the acute pain has subsided.

During hospitalization of several days or longer, stop buprenorphine maintenance therapy, treat the opioid dependence with methadone at a dose of 20 to 40 mg daily, and add on short-acting analgesics for pain control. Naloxone should be available at the bedside. Before discharge, convert the patient back to buprenorphine maintenance.

Because more patients being treated for opioid addiction are opting for buprenorphine, Dr. Miller urges hospitalists to consider obtaining a DEA waiver, which entails taking a one-day course. More details on regulations surrounding buprenorphine are on the Substance Abuse and Mental Health Services Administration Web site.

Bonnie Darves is a freelance health care writer based In Lake Oswego, Ore.

Published in the March 2009 issue of Today’s Hospitalist