OIH — opioid-inducted hallucinations — are more common than many trippers are prepared to admit, largely because they don’t want to be put down as mentally unstable. But there remains the paradox of enjoying, yet fearing the “waking dream” induced by morphine and its synthetic derivatives, now regularly used in end-of-life care, post-operative pain relief and, increasingly, for fun.
With growing resort to opioids as so-called ‘recreational’ drugs, and the consequent rising death rate, the problem has moved from the medical theatre to the street. In the US, more than 50,000 deaths a year are now attributed to opioid misuse. In Australia, 1,045 died from opioid overdose in 2016, a number that has doubled in ten years.
“I think the shit is more like enhanced dreaming than any hallucinatory effect. Still pretty cool though.”
“I love it when it happens because I associate it with the amazingly sublime opiate afterglow feeling.”
“Heavy oxycodone use almost always brings about full-screen open-eyes visuals. I’ll have like blobs of different colours with distinct different textures overlaying my entire vision of the world.”
My brief experience was deeply disturbing — not only for what my brain was projecting onto my consciousness, but for the concern that the phenomenon might represent a permanent disability. After two days, was it ever going to stop?
‘Hallucination’ is defined in the Diagnostic and Statistical Manual of Mental Disorders as “a perception like experience with the clarity and impact of a true perception but without the external stimulation of the relevant sensory organ.” That succinct description explains the attraction of opium for nineteenth century writers such as Samuel Taylor Coleridge, who admitted his poem Kubla Khan depicted images experienced in a drug-induced dream and the sensory experiences of Thomas De Quincey inspired his Confession of an English Opium Eater.
Today, a range of even more powerful opiates – oxycodone, methadone, tramadol, hydromorphone, buprenorphine, pentazocine, fentanyl, and of course morphine – are known to work on the four opioid receptors in the brain. They’ve been named mu, delta, kappa, and nociception. The problem for clinicians is that different drugs work on different receptors.
A recent paper in the journal Cell by a group of researchers including pharmacologist Bryan Roth at the University of North Carolina School of Medicine reports that when the structure of the kappa receptor is bound to a drug molecule like fentanyl, it can produce non-lethal side effects including hallucinations and dysphoria (a state of unease). Roth speculates that when a molecule docks with the kappa opioid receptor, it activates the protein by changing its shape. “That contortion kicks off a network of signals inside the cell, triggering Pathway A (associated with analgestic effects) and Pathway B (associated with things like hallucinations)”, the paper says.
That’s a pretty fair explanation of what happened to me. I underwent surgery three weeks ago to open and wash out a previous surgical wound that had become infected. Laboratory culture tests showed a CRP (c-Reactive Protein, an index of infection) of 190; normal is <10. In recovery, I was in intense pain, and for thirty-five minutes the two nurses worked to subdue it. Later, they told me that had administered first, Endone (oxycodone) and when I didn’t respond, Fentanyl. I do not know the dosages.
The next day, I was transferred to a major hospital for infection management. I slept normally that night but was woken at 5.30am next day for regular tests. When the nurse left, turning out the lights, the television screen on the wall opposite the bed lit up. A spaghetti-like maze of fine green lines started to proliferate and gradually spread across the screen. I was fascinated by the design and wanted to study it further, but when the screen was filled the whole picture moved slowly sideways. It was like a slideshow, but in continuous motion.
The maze was succeeded by a surrealistic picture of swirling figures – indeterminate but recognisable broadly as pleasingly artistic. They in turn merged into shapes like human figures in various postures, but the images seemed out of focus, refusing to be identified. This slow-moving strip of illustrations, all in a green tone, one merging seamlessly into the next, held me transfixed. I wanted to be able to press a ‘pause’ button to stop and examine the pictures in detail, but they moved on, from right to left, inexorably. Then, even more surprisingly, the last frame moved across the screen, disappeared out the left hand edge, and the screen was left black.
If that wasn’t enough for me to suspect that some substance had altered my mind, I closed my eyes to try to go back to sleep, and received the next shock. Silent movies in black and white, were running in my head. They seemed to be visualised as if in a virtual reality headset. It really was virtual reality, because the images were being generated from my subconscious and projected as dreams.
What was strange was the pictures were scrolling down from the top of the screen; they didn’t stop as long as my eyes were closed, but immediately disappeared when I opened them. Some things were realistic and identifiable – the first ‘film’ was a series of supermarket checkout dockets. Their place was taken by more amorphous shapes and designs, not unpleasant but slightly worrying because there was no way of stopping the show except by opening my eyes.
The dream production continued all that day and into the second day. I asked the hospital how long fentanyl was likely to affect me and was told these analgestics usually washed out of the system in twenty-four hours. There wasn’t much interest in my experience; by the third day, my dream factory had shut down and I was left wishing there had been some way of downloading the images for study.
Surprisingly little has been documented in the literature about hallucinatory experiences. Three doctors reported in the journal Anaesthesia and Analgesia they were able to locate only 56 learned papers in the literature on OIH. Significantly for me, they found that hallucinations with fentanyl occurred in as much as 6% of cases during postoperative acute pain management. And they suggested how it works.
I quote their explanation without pretending to understand it:
“One common feature involves opioid-induced dopamine dysregulation…..The dopamine neurons of the midbrain have been linked to activity in the prefrontal cortex, with a possible role for cognitive prefrontal cortex inhibition of dopamine release in the nucleus accumbens (NAc). The NAc also receives ascending sensory input through multiple pathways including the hippocampus, amygdala, and hypothalamus. A phasic dopamine system has been linked to reward-based learning and the assignment of salience to sensory stimuli. Thus, it has been surmised that prefrontal cognitive function can alter salience to sensory stimuli by inhibiting dopamine release in the NAc. The altered salience of sensory stimuli can contribute to the development of hallucinations whereby internal representations are perceived as reality”.
Two days watching what patterns my brain could construct from random thoughts and retained memories was fascinating, but I would not like to live with it. Worse, the literature is clear: continued exposure to opioids will yield diminishing returns, thus requiring higher and higher doses to sustain the effect. The consequences of those can be damaging, even fatal.
My little fentanyl picture show was interesting while it lasted, but I was glad to ring the curtain down permanently.
Geoffrey Luck was an ABC journalist for 26 years