Ask an Expert: Is This Suboxone Withdrawal or Something Else?

By Jeffrey Junig 05/23/17

The body has no memory or knowledge of whether the opioid was prescribed or illicit, swallowed or injected. The body only ‘knows’ that the level of opioid stimulation has decreased.

A woman on a bench with her hand over her heart.
Short answer: Yes.

Q: About five weeks ago I quit Suboxone cold turkey. I was on it for two years at 8mg/day after a decade of opioid abuse. I still have a racing pulse, usually over 100, and I am tired all the time. I had headaches for a few weeks but they seem to be gone now. Could this still be withdrawal or is it something else? I am 58 years old.

Dr. Jeffrey Junig: The short answer to your questions is ‘yes.’ I hope you’ll stick around for the whole story!

Prolonged use of opioid agonists or partial agonists causes ‘opioid tolerance,’ a condition that ultimately results in decreased activity in the affected brain pathways when opioids are discontinued. The mechanisms for tolerance have simple models. For example ‘down regulation’ refers to a decrease in the number of receptors at the synapse that reduces the effects of opioids. Tolerance also causes opioid receptors to become less sensitive to opioids. Beyond the models, tolerance requires the actions of a number of non-opioid neurotransmitters and enzymatic processes.

The processes behind tolerance are complex, but the effects of tolerance are straightforward. During early opioid use, pain pills and heroin activate endorphin pathways. Endorphin pathways become dependent on that activation to the point where a person’s natural endorphins are no longer strong enough to activate those pathways. When the person stops taking pain pills or heroin, the activity in endorphin pathways stops.

The brain is designed to maximize efficiency. After severe blood loss from trauma, decreases in blood pressure activate nerve pathways that contain vasopressin. Some of the pathways extend to the pituitary gland and release vasopressin the bloodstream, where the neurotransmitter/hormone constricts blood vessels, increases the clotting activity of platelets, and causes kidneys to retain water and sodium to boost blood volume. Vasopressin pathways in the hypothalamus activate brain regions that increase thirst, and pathways to the brainstem increase the sensitivity of ‘baroreceptors’ that regulate blood pressure and cardiac output.

In the same way, activation of the endorphin pathways, for example after traumatic injury, triggers many brain functions including elevation of mood, pain relief, and redistribution of blood flow from the gastrointestinal system to muscle tissue. The coordination runs even deeper in that the precursor molecule for endorphin contains ACTH, the hormone that stimulates the adrenal gland to produce more cortisol. Anything that triggers the production of endorphins also triggers the release of ACTH and stress hormones.

The coordination between endorphin pathways, stress hormones, and the autonomic nervous system (which regulates the mechanics of blood pressure, blood volume, digestion, and other processes) results in a range of symptoms when endorphin pathways shut down during opioid withdrawal.

Back to the original question…. People often discuss the withdrawal symptoms after one opioid or another and assert that methadone, buprenorphine, or heroin causes ‘the worst withdrawal ever.’ But the body has no memory or knowledge of the offending opioid, or whether the opioid was prescribed or illicit, swallowed or injected. The body only ‘knows’ that opioid tolerance is elevated, that the level of opioid stimulation has decreased, and that opioid pathways are therefore relatively quiet. The severity of withdrawal symptoms comes down to two factors: the degree of tolerance, and how fast the opioid stimulation is reduced. Nothing else matters.

The opioid activity of buprenorphine is limited by the ceiling effect, limiting the degree of tolerance and therefore limiting the severity of withdrawal. Buprenorphine also leaves the body over days, not hours as with heroin. The longer half-life of buprenorphine reduces the peak severity of withdrawal while prolonging withdrawal by a few days.

Jeffrey T Junig, MD, PhD, received his PhD in Neuroscience from the Center for Brain Research and MD with Honor from the University of Rochester School of Medicine and Dentistry. Full Bio.

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