The opioid crisis is one of the biggest problems our society is facing. Stories of celebrity overdoses, high-profile drug busts, and lethal new compounds of fentanyl are constantly in the media. While illicit opioid abuse is a huge problem, the majority of drug abuse does not begin with legitimately prescribed pain medication from well-trained medical professionals. In fact, patients with pain who are properly managed by pain specialists and surgeons do not typically become addicted. Nevertheless, even closely monitored patients who are compliant with their medication regimen can develop numerous health issues. On a positive note, the publicity of the opioid epidemic has spurred the advancement of interventional procedures that have been shown to effectively reduce opioid consumption.
Chronic pain medication users nearly always develop opioid tolerance–the physiologic need for higher doses over time to maintain the same amount of pain relief. With the increasing doses comes increased side effects. Furthermore, patients with opioid tolerance must have a consistent amount of medication in their system, or they can experience extremely unpleasant withdrawal symptoms. Not only is this lifestyle of chemical dependence burdensome and costly, it can also have severe health consequences.
An often underappreciated side effect of chronic opioid use is hormonal suppression. Opioid-induced androgen deficiency (OPIAD) can lead to decreased levels of sex hormones such as testosterone, luteinizing hormone, and follicle-stimulating hormone. In men, this can mean erectile dysfunction and reduced libido. Muscle mass can be reduced and replaced with increased fat accumulation. In women, OPIAD can lead to infertility, hot flashes, and osteoporosis. Hormone monitoring and replacement may be required to counteract these effects of opioids on the endocrine system.
Another potential problem that is often overlooked is opioid-induced hyperalgesia (OIH). OIH is an intensified pain state that is actually caused by the opioids, which may seem counterintuitive. In some people, the constant stimulation of the opioid receptors by pain medications causes the pain pathways in the body become more sensitized. This results in the patient’s pain perception being amplified. If not diagnosed properly, this can lead to higher doses of medications being prescribed, resulting in a vicious cycle of worsening pain.
Long-term opioid use can have important effects on mental function as well. Studies have shown that opioids can cause chronic cognitive deficits, depression, and apathy. Opioids can also independently increase fall risk, making this combination of side effects especially dangerous. In the elderly, who have slowed metabolism of opioids, falls can lead to fractures, hospitalizations, loss of independence, and increased mortality rates. With aging comes spine and joint degeneration, but opioids should be prescribed with caution in this population.
The majority of opioid users, short-term or long-term, will encounter constipation that can be severe. The intestines contain receptors that function to stimulate the movement of bowel contents. Opioids act on these receptors in a way that blocks them from functioning. Gut motility slows, sometimes to the point where even prescription laxatives are ineffective. Patients may go weeks without a bowel movement, and for some, the nausea, vomiting, and abdominal discomfort associated with this can be worse than the initial pain itself.
The most dangerous side effect of opioids is suppression of the respiratory system. While it may be intuitive that this can occur in cases of overdose related to addiction, abuse, and misuse, fatal respiratory depression can also occur in compliant patients through accidental overdose. Opioids are primarily metabolized by liver enzymes. Non-pain medications and herbal supplements can affect the activity level of these enzymes. In a chronic pain medication user, a newly added non-pain medication that reduces enzyme activity can cause increased build-up of the pain medication. Respiratory depression and death can ensue, especially in respiratory-compromised individuals such as those with COPD or emphysema.
As opioid medications are becoming a last-resort treatment for pain, interventional procedures have become the first-line treatment for pain. Treatments such as spinal cord stimulator implants, devices that can alter pain signal transmission, have been shown to reduce opioid consumption significantly. Radiofrequency ablation, the cauterizing of the sensory nerves of painful joints, has also been shown to reduce opioid use. Measuring opioid reduction as an outcome is becoming a standard metric in clinical research trials. Many studies evaluating regenerative medicine therapies, such as platelet-rich plasma (PRP) and stem cell therapy, are determining treatment success by this measure. PRP and stem cell treatments for spine and joint pain are continuing to gain ground as natural, side effect-free alternatives to pain medications.