In this episode I’ll discuss how I provide analgesia & sedation to critically ill patients who have taken buprenorphine.

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Buprenorphine is an opioid partial agonist. It is used to treat acute & chronic pain, opioid withdrawal, and opioid dependence.

Buprenorphine has a very high affinity for the mu opioid receptor. This high affinity results in competition with or displacement of other opioid analgesics at the mu opioid receptor. Due to buprenorphine being a partial mu opioid agonist, it’s opioid effects plateau at higher doses and it behaves like an antagonist.

The half-life of buprenorphine depends on the dosage form used, but it is generally greater than 24 hours.

As a result, it can be challenging to provide analgesia and sedation to critically ill patients who have recently taken buprenorphine. There are several different ways to work through this challenge.

The first decision to be made is whether or not to continue the buprenorphine. Either continuing or discontinuing the buprenorphine can be a legitimate option.

When buprenorphine is continued Dividing the total dose

If the buprenorphine is continued, and the analgesia requirements are low, dividing the buprenorphine dose from a single daily dose into multiple doses throughout the day may be sufficient.

Adding breakthrough opioid therapy

Whether or not the buprenorphine dose is divided, additional breakthrough opioid analgesic dosing may be used. I’ve found that the effective dose of breakthrough analgesic is nearly impossible to predict. I’ll just pick a moderate dose of an opioid like 50 mcg fentanyl IV or 1 mg hydromorphone IV and titrate it as necessary to achieve the analgesic or sedation goal. Most patients will need relatively large doses of the breakthrough opioid for sufficient effect.

When buprenorphine is discontinued

If the buprenorphine is discontinued, it will need to be replaced with something – typically either methadone or another opioid analgesic.

Replacement with methadone

Methadone at a dose up to 40 mg orally is sufficient to replace the effects of buprenorphine or at least prevent withdrawal symptoms. Additional breakthrough opioid doses may need to be given.

Replacement with opioid agonists

Buprenorphine can also be discontinued and replaced with traditional opioids. Just like with breakthrough doses, I’ve found that the effective dose of opioids to replace buprenorphine is nearly impossible to predict. Most patients will need relatively large doses of the breakthrough opioid for sufficient effect.

For example, I encountered a patient who had recently stopped taking 20 mg of oral buprenorphine daily. The patient was mechanically ventilated for postoperative respiratory failure and needed continuous analgesia and sedation. A fentanyl infusion was started and the patient tolerated a continuous infusion of 200 mcg/hr fentanyl. This was reduced to 175 mch/hr and the patient was able to be weaned from the ventilator and transitioned back to oral buprenorphine the next day.

Rescue ketamine therapy

If none of the above strategies work for providing analgesia and sedation to a critically ill patient on buprenorphine, ketamine can be used as a “rescue therapy”.

I discussed the use of ketamine in critical care in detail in episode 16.

If breakthrough analgesia is needed, I would use ketamine boluses at a dose of 0.15 to 0.3 mg/kg IV. If continuous analgesia is needed, I would start an infusion at 0.1mg/kg/hr and increase every 30 minutes to a max of 0.4 or 0.5 mg/kg/hr.

If buprenorphine therapy needs to be restarted after other opioids are used for acute pain management, there is a chance resuming buprenorphine will precipitate opioid withdrawal.

To prevent acute withdrawal, a patient receiving a full opioid agonist regularly should be in mild opioid withdrawal before restarting buprenorphine therapy.

When can a critical care provider without a special “X number” DEA prescribe buprenorphine?

Typically special registration with the DEA is required for physicians to prescribe buprenorphine for the purpose of treating opioid addiction.

Exceptions to this rule do exist, as discussed at the Substance Abuse and Mental Health Services Administration Website:

Neither the Controlled Substances Act (as amended by the Drug Addiction Treatment Act of 2000) nor DEA implementing regulations (21 CFR 1306.07(c)) impose any limitations on a physician or other authorized hospital staff to maintain or detoxify a person with an opioid treatment drug like buprenorphine as an incidental adjunct to medical or surgical conditions other than opioid addiction.

Thus, a patient with opioid addiction who is admitted to a hospital for a primary medical problem other than opioid addiction, e.g., myocardial infarction, may be administered opioid agonist medications (e.g., methadone, buprenorphine) to prevent opioid withdrawal that would complicate the primary medical problem. A DATA 2000 waiver is not required for practitioners in order to administer or dispense buprenorphine (or methadone) in this circumstance. It is good practice for the admitting physician to consult with the patient’s addiction treatment provider, when possible, to obtain treatment history.

I interpret this to mean that a critically ill patient on buprenorphine can continue to receive buprenorphine without consulting a provider with an ‘X’ DEA number as long as their critical illness would be exacerbated if the buprenorphine was not continued.

If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.

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