Case Report: Dust Remover Inhalant Use Disorder in an Individual in Early Remission from Alcohol Use Disorder Treated with Naltrexone

Introduction

Inhalants are a chemically diverse class of substances widely available and minimally regulated due to their intended use in everyday products (cleaning supplies, gasoline, markers, paints/paint thinners, refrigerants, and propellants). The prevalence of inhalant use in the youth population has been estimated to be about 8% to 15%, and rates of conversion to an inhalant use disorder (IUD) may be as high as 18% to 47%. ¹ Emergency department (ED) visits related to injuries caused by dust removers are on the rise. ² Despite the potential for significant injury, even addiction specialists may fail to detect this often-overlooked disorder. Inhalants are not detected by standard drug screening tests, and less is known about the clinical presentation and treatment of IUDs.

Here, we present a case of dust remover-IUD. Over 99% of the content of dust removers is pure difluroethane (DFE), with a trace amount of bitterant included in some products to deter abuse. ³ Several cases of excessive dust remover use have been documented in the literature, mainly regarding serious medical complications, including organ failure,^4,5 frostbite injury, ⁶ skeletal deformities, ⁷ cardiac impairment,^8,9 motor vehicle accidents,^10,11 psychosis, ¹² and even death ¹³ . Chronic inhalant use is also associated with significant long-term morbidity mostly related to nerve damage, including cerebellar dysfunction, hearing loss, vision loss, and distal sensory loss ¹⁴ . However, few reports have focused on the clinical course of dust remover consumption through the lens of an addictive disorder.^15,16

Case

A 52-year-old man presented to the ED for assistance with excessive dust remover use. He reported initiating use 1 year prior in the context of his mother’s passing. He reported initially using about 1 can per week, which escalated to 4 to 8 cans daily from the beginning of each month until he ran out of money (about $1000 a month spent on dust removers) 2 weeks before the end of each month. He described withdrawal symptoms, including tremors, anxiety, nausea, and restlessness during these periods of abstinence. During intoxication, he described experiences of intense euphoria and visual hallucinations, followed by 3 to 4 hours of decreased consciousness and ulterior amnesia. He reported using dust remover because it could not be detected on screening tests, as he was on probation for driving under the influence of alcohol. He had established abstinence from alcohol 1 month before initiating inhalant use. He also reported using it to cope with military trauma and grief.

He had initially tried brands that included bitterants but found their taste intolerable leading to him only using 1 can that day due to persistent vomiting. He reported that the use of bitterants as a deterrent is a “really effective” measure that can prevent the use of these agents. Other than that, he denied any preferences for other brands. He noted that the primary store he used to procure the inhalant would often restrict his in-person purchases to no more than 2 cans at once, but he was able to buy more through an online ordering service at the same store. He recalled seeing warning labels on all canisters in “fine print.” He was aware of the potential for fatal consequences as he knew someone in the military who had died from dust remover use during service. He was also able to learn which brands do or do not include bitterants in their products.

A few days prior to this presentation, he reported that he had “lost consciousness” several times with the dust remover canisters on top of him, resulting in frostbite burns to the palms of both hands, his chest, as well as his lower lip. His use led to a recent breakup from his long-time girlfriend. These consequences prompted him to present voluntarily for treatment. One of these syncopal episodes, experienced months prior, was associated with marked weakness and neuropathy in his lower and upper extremities, which required a 3-month stay in a skilled nursing facility for physical rehabilitation. He eventually regained the ability to walk independently but reported continued pain and paresthesias in his hands and forearms.

He also reported the use of approximately half to one packet of cigarettes a day. He denied any other recent substance use besides occasional cannabis. His history was significant for diagnoses of recurrent major depressive disorder (MDD), post-traumatic stress disorder (PTSD), severe alcohol use disorder (AUD), and severe tobacco use disorder (TUD). At the time of the presentation, he had about a year of abstinence from alcohol. His home medications included duloxetine 60 mg daily, quetiapine 50 mg twice daily, and pregabalin 200 mg 3 times daily.

The patient was admitted to the inpatient psychiatric unit. Laboratory findings upon admission were significant for elevated white blood cell count (11.99 K/µL; reference range 3.7-8.4), elevated creatinine (Cr: 1.7 mg/dL; reference range 0.57-1.25; baseline 1.14 mg/dL), decreased estimated glomerular filtration rate or eGFR (48; reference range >60), and urine drug screen positive for cannabis. He was initially monitored under an alcohol withdrawal protocol, given reports suggesting that inhalants might function as depressants through gamma-aminobutyric acid (GABA) receptors similar to alcohol. ¹⁷ He did not ultimately require any medications under this protocol.

He was discharged directly to our Substance Abuse Residential and Rehabilitation Treatment Program (SARRTP) at his request, where he had already received treatment about 2 years prior for treatment of AUD. He received physical therapy and noticed an improvement in his neuropathy. Nephrology was consulted with a presumptive diagnosis of acute tubular necrosis. There are several cases described in the literature linking the use of inhalants with the development of this complication. ¹⁸ A renal ultrasound and urinary creatinine/urinary protein ratio or Ucr/Uprot ratio were within normal limits. His Cr and eGFR eventually normalized. During his 8-week stay, he engaged in regular group and individual psychotherapy for substance use disorders and PTSD, including prolonged exposure therapy. Oral naltrexone was initiated at 50 mg daily for AUD and off-label for IUD. Apo-varenicline was added and titrated to 1 mg twice daily for TUD. Duloxetine was increased to 60 mg twice daily for MDD. Over the course of his treatment, he reported a reduction in cravings for inhalants. He successfully completed the program and was discharged home with outpatient follow-up.

The patient was contacted approximately 8 and 12 months following discharge. He reported that he had returned to use of alcohol for about a month shortly after discharge from SARRTP due primarily to social isolation but was able to regain abstinence thereafter. His use of alcohol at that time was significantly lower, around a 6 pack of beer per week. He also used dust remover 1 time during that period. He reported taking his medications as prescribed, including during his return to use. He was also attending weekly support groups together with individual therapy. At present, he does not have cravings for dust remover despite cues in his environment, such as online advertisements.

Discussion

The development of IUD is not well described in the literature, even less so for dust remover-DFE. This case is notable for several reasons. First, this patient transitioned rapidly to using dust remover after a very brief period of abstinence from alcohol. Ethanol and DFE may share common biological targets in the brain. Volatile hydrocarbons, including DFE, have been compared to volatile anesthetics as well as central nervous system depressants (alcohol, benzodiazepines, and barbiturates). ¹⁷ These molecules tend to cause their effects by positively modulating ligand-gated GABA-A receptors and attenuating the function of glutamatergic N-methyl-D-aspartate (NMDA) receptors^19,20; however, studies of potential specific DFE neurobiological effects are lacking.

Second, the severity of the medical consequences of this patient’s IUD was very significant; however, the few restrictions available to prevent misuse of these substances were easily circumvented. This patient’s experience points to the need for stronger and more standardized regulations. Such regulations were indeed proposed by a recent petition to the Consumer Product Safety Commission, including the addition of bitterant to all dust remover products and adding more prominent warning labels. ³ The regulations were unfortunately not approved, citing a need for more research on the best ways to mitigate harm. This case is an example of the potential effectiveness of the use of these measures from a public health perspective.

Another important element of this case has to do with treatment. The patient received evidence-based treatments: (1) trauma-focused psychotherapy and (2) psychopharmacological treatment, including naltrexone for the dual purpose of treating AUD and IUD based on its use in 2 prior reports^16,21 and shared theoretical targets between alcohol and DFE. Interestingly, he returned to use both alcohol and the inhalant for a brief period of time before regaining back full abstinence from both substances. It is tempting to hypothesize that the previous existence of an AUD was a neurobiological substrate that facilitated the development of an IUD, and once the latter was developed, both of these combined into a single addictive disorder with a similar course and response to treatment. Although many factors contribute to the comorbidity of certain addictive disorders, ²² there is some empirical evidence for cross-tolerance between substances,^23,24 which may increase the risk of developing addiction to another substance.

Finally, this case represents an unusual age presentation. Most individuals who use inhalants tend to distribute in the early-late adolescence (12-17 years) age range. ²⁵ On the other hand, some studies suggest that the presence of a mood/anxiety disorder and an AUD are likely the main risk factors associated with the progression from recreational inhalant use to the development of an IUD. ²⁶ Despite the legal requirements to maintain abstinence from a single specific substance, as this patient had been on probation due to a past DUI, his addiction process was not receiving evidence-based treatment by the time this patient presented to the ED. It is unknown whether the use of different interventions, such as naltrexone in the oral or the long-acting injectable forms for the treatment of AUD, could have prevented or not the development of the IUD.

There are several limitations to this report. We have presented a single case of DFE-IUD; therefore, our ability to make broad generalizations is limited. The patient has also received different treatment modalities, so extrapolating the efficacy of any one of those treatments for the treatment of IUD is challenging. Furthermore, many patients may not have access to a similar array of supportive and psychotherapeutic interventions, thus limiting generalizability.

The strengths of this report include the long duration of follow-up with this patient and the detailed information we were able to obtain related to his presentation.

In conclusion, the recreational use of DFE is associated with serious and life-threatening psychiatric and other medical consequences. The easy availability and lack of regulation of substances, such as DFE, make this phenomenon a potential public health threat. We advocate for regulatory measures (e.g., the addition of bitterants) and better education for the general public and medical communities. We also propose the implementation of screening questions about potential inhalant use in the ED, primary care, and specialty addiction clinics due to the difficulties in detecting these substances in regular practice. We have presented a case that, consistent with previous studies with other inhalants, provides indirect evidence for a connection between DFE and AUD in both the longitudinal course and response to treatment. Further research about the interplay of these disorders, including the use of biomarkers for treatment response, is warranted.