| One-Minute Clinician

Pain and Pharmacotherapy

When you consider where we are with the pharmacotherapy of pain at this current time, I think we are still struggling in the sea of two competing public health crises. Certainly, we still have this enormous cohort of people who suffer with poorly controlled pain, yet, on the other hand, the opioid crisis continues to worsen. I often think of the song I Want a New Drug because I wish we had a new drug that could fix this and that was not habituating yet would adequately address pain, and we don’t have that. So I think our best defense is to continue to educate prescribers and practitioners and use good risk-mitigation strategies to try and do our very best job for these patients while still not worsening the opioid crisis. In terms of other medications, ketamine, lidocaine, and methadone are certainly special pharmacotherapeutic agents. Methadone is becoming increasingly mainstream, and we use it all the time in palliative care. It’s a really excellent opioid because it has multiple mechanisms of action. Not only is it a mu-opioid agonist, it inhibits the reuptake of serotonin and norepinephrine, and importantly, it’s a mild N-methyl-D-aspartate receptor antagonist. This makes it a useful opioid for patients who have mixed pain pathology. It also comes as a concentrated oral solution. It’s a long-acting opioid we can use twice a day or 3 times a day and use a very low volume for patients who have difficulty swallowing. Increasingly, methadone is being used mainstream, but, of course, no opioid is a free ride. You have to consider all the ramifications of opioid therapy, and with methadone, of course, we have to consider the risk for QT interval prolongation. Ketamine is a strong N-methyl-D-aspartate receptor antagonist, and increasingly, we’re seeing people at end of life who come to us particularly in hospice or palliative care on very high doses of opioid therapy—10, 20, 30 mg an hour of IV continuous infusion hydromorphone—and they’re experiencing opioid induced hyperalgesia. So we’ll use a medication like ketamine to reverse that with very good effect. It’s not a slam dunk. It seems like maybe 50% of patients will have a really superb response to ketamine and some maybe not so much, so you have to pick your patients carefully. I think we really are on a cusp of trying to figure out how to best use ketamine. We see this increasing amount of literature of using it for depression. Emergency departments are using it for patients with suicidal ideations, so I think we really are poised to explore all the best uses of ketamine. And lidocaine can be used intravenously for very, very difficult neuropathic pain. We don’t need it often, but when we do use it occasionally, it can be just a ticket.