Lessons for Infectious Disease Doctors: Treating HIV, Pain, and Mental Illness

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HIV can lead to chronic pain caused by the infection, subsequent inflammation, or side effects of HIV medication. A staggering 60% of patients with HIV experience chronic pain compared with only [[11% https://nccih.nih.gov/news/press/08112015]] of the general population, according to Robert Bruce, M.D., M.A., M.Sc., with Yale University, who presented the latest research on pain and HIV at IDWeek 2018 in San Francisco.

"HIV itself may have an impact in modulating pain or even causing pain our patients," said Bruce. A growing body of research suggests that a protein on the surface of the HIV virus called gp120 [[affects pain https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4077969/]], either by causing pain directly or by blocking medications like morphine from working properly.

It's also well established that psychological trauma and mental illness can lead to physical manifestations of pain, which is why it's important for infectious disease doctors to understand the dos and don'ts of treating chronic pain in HIV patients, said Bruce.

Bruce built his career studying the intersection of pain, mental health, and infectious disease. Along the way, he's cultivated practical steps for treating HIV-positive patients experiencing chronic pain -- tips he shared with attendees at IDWeek 2018.

Chief among Bruce's recommendations was that patients receive a thorough physical examination because the physical underpinnings of pain are often missed in an initial exam.

He also coached conference attendees on the importance of recognizing (and respecting) the psychosocial origins of pain. Finally, he offered some practical tips on identifying opioid-seeking behavior and keeping thorough records in an era of increased scrutiny over opioid prescriptions.

He observed that infectious disease clinicians tend to find it difficult to treat pain. Unlike with HIV, there's no easy way to diagnose pain or measure treatment effects. HIV treatment is quantified by measuring CD4 counts, he noted. Conversely, the pain scale (a 1-10 self-assessment of pain levels) is notoriously imprecise.

"My patients have never rated their pain as less than 10," he said, "so when we think about evaluating people with pain, we have to be very systematic."

With such a subjective evaluation tool ("I hate the pain scale," Bruce said) it's useful to instead help patients identify discrete, tangible goals of pain treatment, such as being able to walk up the stairs in their house or pick up their grandkids from school.

"I always tell patients, the goal is not to be pain free," he said. "For most of our patients, it's really about helping people achieve a definable outcome."

Related: This Week in HIV Research: Pain, Opioids, and Viral Suppression

Pro Tip: Always Perform a Physical Examination

Physical exams are the bread and butter of medicine. However, Bruce noted with dismay that countless patients have been referred to him for pain treatment without ever having had a physical exam.

"I'm always amazed at the number of people who don't actually examine patients," he said. Though pain symptoms are often amorphous and vague, some patients experience pain because of easily identified injuries or pathology, such as an infection or ruptured disk.

For this reason, a physical exam should always be a key component of any pain consultation, Bruce said. But for many HIV-positive patients, pain is a whole-body experience related to the disease itself and not pinpointed to one particular injury.

"One of the complicating factors in HIV is that people have neuropathic pain, but the cause is differential," Bruce said. For guidance on treatment of neuropathic pain, Bruce pointed to the Infectious Diseases Society of America [[clinical practice guidelines https://www.ncbi.nlm.nih.gov/pubmed/29020263]] he co-authored, which were published last year.

Respect the Psychological Causes of Pain

Patients experience pain in different ways and for different reasons. Many patients perceive pain as directly related to an injury or as neuropathic pain related to HIV, while others experience pain as a manifestation of trauma, depression, or another mental illness.

"Don't blow off the fact that trauma can cause physical pain," said Bruce. "How the patients experience pain is colored by mental health."

For example, he noted, patients who have been sexually assaulted may report pelvic pain or rectal pain -- even if the assault took place years ago.

And, no matter what the cause, the experience of chronic pain can exacerbate mental illness. Pain that started from an injury may ultimately lead to depression, triggering a vicious cycle of ever worsening pain symptoms.

That's precisely why Bruce refers all his pain patients to a behavioral health clinic, regardless of their underlying cause of pain. He recommends cognitive behavioral therapy, yoga, and acupuncture for many of his patients.

Check Your Assumptions About Opioids

Even in the midst of a national opioid epidemic, some clinicians still make the mistake of assuming their patient isn't the type to become addicted to opioids, Bruce said. But he cautions that it's important to ask every patient about any prior substance use and a family history of addiction.

If opioids are prescribed, "document everything," including a strong rationale for why a patient is a good candidate for this treatment. "We're in an era of opioid restriction," Bruce said, and it's not uncommon for the U.S. Drug Enforcement Administration to ask for records related to opioid prescriptions.

Once patients are prescribed opioids, perform regular urine tests, he added.

"Urine toxicology is important, and we do it for everyone," he said. If a patient does test positive for opioid use, "the first thing is not to blame the patient," he adds.

He sought to dispel the commonly held myth among clinicians that it's safer to continue prescribing opioids -- even if patients don't need them -- because it will keep patients engaged in care.

Not only is it unethical to prescribe medicine for non-medical reasons, but a [[2018 CROI abstract http://www.natap.org/2018/CROI/croi_145.htm]] found that long-term opioid treatment did not impact retention in care for HIV patients with pain.

For those who want to transition their patients away from opioids, the best possible method is combination treatments that address all aspects of pain: physical, cognitive, and behavioral.

"Pain itself is very complicated," said Bruce. "I like to think of it as multimodal. There are many things that impact pain and how people experience pain."