Volatile substance abuse

Variability in cardiovascular functions and baroflex sensitivity following inhalation of petroleum hydrocarbons

Objective:

Although petroleum products are useful chemical compounds which form an integral part of our modern technology, they have been reported to cause deleterious effect on health following their inhalation. Petroleum hydrocarbons-dependent health hazards and their mechanisms have been associated with the routes of administration. This study, therefore, aimed at the isolation and chemical characterization of various petroleum products, and also investigating in rat model of Sprague dawley strain, the variability in cardiovascular functions and possible mechanism following inhalation of petroleum products.

Materials and Methods:

Control rats were not exposed to any form of petroleum products, while the petrol-exposed, diesel-exposed, and kerosene-exposed were exposed to petrol, diesel, and kerosene respectively.

Results:

When compared with the controls, all exposed groups showed a significant (P<0.05) increase in the systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP), and heart rate (HR). In comparison with the control, exposure to petroleum products also led to significant (P<0.05) increase in baroreflex sensitivity in the diesel- and kerosene-exposed rats. Baroreflex sensitivity was comparable in the control and petrol-exposed rats (P>0.05). Body weight gain was significantly (P<0.05) reduced in petroleum products exposed rats.

Conclusion:

These results suggest that the variability of cardiovascular functions associated with inhalation of petroleum products is in attendant to baroreflex sensitivity and resetting of arterial pressure.

White-matter abnormalities in adolescents with long-term inhalant and cannabis use: a diffusion magnetic resonance imaging study

BACKGROUND

There is growing evidence that inhalants are neurotoxic to white matter, yet limited work has been conducted to investigate the neurobiologic effects of long-term exposure among adolescent users, despite inhalant use being most prominent during this developmental period.

METHODS

We used diffusion tensor imaging to examine white-matter integrity in 11 adolescents who used inhalants, 11 matched cannabis users and 8 drug-naive controls.

RESULTS

Although both groups of drug users had white-matter abnormalities (i.e., lower fractional anisotropy), abnormalities were more pronounced in the inhalant group, particularly among early-onset users.

LIMITATIONS

The findings of this study should be considered in light of its small sample size, cross-sectional design and the complex psychosocial background of long-term inhalant users.

CONCLUSION

White-matter abnormalities may underpin long-term behavioural and mental health problems seen in individuals with long-term inhalant use.

The mysterious practice of petrol sniffing in isolated indigenous groups

The practice of petrol sniffing is a unique and poorly understood phenomenon that is associated with substantial morbidity, mortality and social devastation in affected remote Indigenous communities. For these groups and for the wider community, much mystery has surrounded the practice and its effects. Here we introduce the epidemiology of petrol sniffing among Indigenous groups internationally, review its impact on the brain, behaviour and social functions and summarise related interventions.

Choice of nitrous oxide and its subjective effects in light and moderate drinkers

BACKGROUND

Alcohol-drinking status has been shown to modulate the reinforcing and subjective effects of a number of drugs. We have previously published two studies on the modulating effects of alcohol-drinking status on choice for, and subjective effects of, nitrous oxide, but the results were equivocal. Using a methodology different from our previous studies, we sought to determine in a more definitive fashion the degree to which the choice of nitrous oxide and its subjective effects were modulated by drinking status.

METHODS

Four concentrations of nitrous oxide (0, 20, 30, and 40%) were administered to 16 moderate drinkers (MDs) and 16 light drinkers (LDs) across four 3.5-h sessions. During experimental sessions, subjects first completed two 10-min sampling trials in which one of the nitrous oxide concentrations and placebo (100% oxygen) were inhaled. Subjective and psychomotor tests were given 5min into each sampling trial. During the subsequent choice period, subjects were allowed to choose what they wanted to inhale (drug, placebo, or "drug-free air") on nine contiguous 5-min choice trials.

RESULTS

Choice of nitrous oxide was modulated by drinking status: MDs but not LDs chose nitrous oxide significantly more times than placebo, and MDs also chose nitrous oxide significantly more times than did LDs. At each active nitrous oxide concentration, MDs reported more abuse liability-related subjective effects, especially at the 20% and 30% concentrations.

CONCLUSIONS

The results of the present study provide more conclusive evidence that choice as well as subjective effects of nitrous oxide is modulated by alcohol-drinking status.

Laboratory diagnosis of toluene-based inhalants abuse

Toluene is the main substance contained in products used as inhalants. The frequent abuse of toluene-based inhalants requires the definition of a simple laboratory parameter that allows acute exposure assessment. This study aimed at defining urinary hippuric acid (UHA) levels related to intentional exposure to toluene, and to correlate them to blood toluene concentration (BT).

METHODS

BT and UHA levels were measured in 65 homeless adolescents of Porto Alegre, Brazil.

RESULTS

Toluene was detected in 91.9% of the investigated population, who presented BT levels from 0.5 to 83.7 microg/mL. There was good correlation between UHA and BT concentrations (r = 0.78), and in homeless adolescents, UHA levels higher than 3.0 g/g creatinine indicate intentional exposure to toluene.

CONCLUSIONS

The determination of UHA concentrations can be used as a screening method for the detection of intentional exposure to toluene, but its diagnosis must include BT toluene dosage, as well as circumstantial and clinical evidence.

Inhalant abuse among adolescents: neurobiological considerations

Experimentation with volatile substances (inhalants) is common during early adolescence, yet limited work has been conducted examining the neurobiological impact of regular binge use during this key stage of development. Human studies consistently demonstrate that chronic use is associated with significant toxic effects, including neurological and neuropsychological impairment, as well as diffuse and subtle changes in white matter. However, most preclinical research has tended to focus on acute exposure, with limited work examining the neuropharmacological or toxicological mechanisms underpinning these changes or their potential reversibility with abstinence. Nevertheless, there is growing evidence that commonly abused inhalants share common cellular mechanisms, and have similar actions to other drugs of abuse. Indeed, the majority of acute behavioural effects appear to be underpinned by changes in receptor and/or ion channel activity (for example, GABA(A), glycine and 5HT(3) receptor activation, NMDA receptor inhibition), although nonspecific interactions can also arise at high concentrations. Recent studies examining the effects of toluene exposure during the early postnatal period are suggestive of long-term alterations in the function of NMDA and GABA(A) receptors, although limited work has been conducted investigating exposure during adolescence. Given the critical role of neurotransmitter systems in cognitive, emotional and brain development, future studies will need to take account of the substantial neuromaturational changes that are known to occur in the brain during childhood and adolescence, and to specifically investigate the neuropharmacological and toxicological profile of inhalant exposure during this period of development.

Choice of sevoflurane and its subjective and psychomotor effects in light and moderate drinkers

BACKGROUND

Sevoflurane, an inhalant of the volatile anesthetic class, has neurobiological and behavioral effects in common with abused inhalants and ethanol. We sought to determine if choice for subanesthetic doses of sevoflurane, and its subjective and psychomotor effects, would differ as a function of alcohol-drinking status in healthy volunteers.

METHODS

The effects of four concentrations of sevoflurane (0, 0.2, 0.4, 0.8% sevoflurane in oxygen) were studied in 16 light drinkers and 16 moderate drinkers. During each of four sessions, subjects sampled a concentration of sevoflurane and 100% O(2) (placebo) for 10 min each. Subjective and psychomotor testing commenced 5 min into each sampling trial. Later, within the session, subjects chose nine times, once every 5 min, among sevoflurane (e.g., "Agent A"), placebo (e.g., "Agent B," 100% O(2)), or neither (and were administered 100% O(2), identified as "drug-free air").

RESULTS

Choice for sevoflurane at the 0.4% concentration was significantly higher in the moderate drinkers than in the light drinkers. A number of subjective effects reported during inhalation of sevoflurane were markedly lower in the moderate-drinking group than in the light-drinking group. However, psychomotor impairment induced by sevoflurane was similar in magnitude in both groups.

CONCLUSIONS

Alcohol-drinking status affected sevoflurane choice. The results are consistent with several studies comparing light and heavier drinkers, using other drugs. Although both drinking groups were similarly impaired by sevoflurane, the moderate drinkers reported less of a subjective response than light drinkers, suggestive of cross-tolerance.

Solvent use among young Irish adolescents — a growing concern for youth workers, teachers and parents?

The research aimed to identify ‘(1) current volatile solvent use practices, (2) health beliefs and perceived effects of volatile solvent use, (3) social dynamics of volatile solvent use, (4) significance of reputation, and (5) barriers to volatile solvent use intervention’ in a sample of Irish adolescents (Carroll et al, 1998, p1; Anderson & Loomis, 2003). Semi‐structured interviews were conducted with 20 adolescents who reported inhaling volatile solvents, during the course of doctoral research (n=1,400) investigating substance misuse among adolescents aged 12 to 18 years in Ireland. Their average age was 13.2 years, and they used a range of substances. Solvent users were found to be most commonly congregated in small peer and sibling groups and one young male also reported using alone. These young people indicated their average age of initiation of inhalant use as 10.3 years and most did not use inhalants after the age of 13 years. This coincided with first‐time alcohol use, at an average age of 12.5 years and experimental use of cannabis in some. All reported some awareness of short‐term medical risks involved in solvent use, and most commented on negative effects, such as headaches, dizziness and vomiting. Teachers, probation and juvenile liaison officers, health promotion and drug education workers, youth workers, social workers, and parents should ‘familiarise themselves with the real world experiences of adolescent volatile solvent users’; in order to develop appropriate and timely drug education interventions (Carroll et al, 1998 p6).

Death associated with volatile substance inhalation—Histologic, scanning electron microscopic and energy dispersive X-ray spectral analyses of lung tissue

The investigation of deaths due to the inhalation of volatile substances may be complicated by a lack of scene and autopsy findings. Mechanisms of death may not be determinable at autopsy, and there may be very few markers of inhalant abuse. A 21-year-old man is reported who died from the combined effects of methadone toxicity and toluene inhalation. Histological examination of the lungs revealed congestion and edema, as well as particles of blue, pigmented material within the interstitium and in macrophages. Scanning electron microscopy was undertaken, revealing that the particles contained granules that measured 0.15-0.2microm in diameter, within the range of mean particle sizes for inorganic paint pigments. Energy dispersive X-ray spectral analysis of the granules demonstrated a significant percentage of titanium (12%) confirming their origin from paint. Ancillary investigations such as electron microscopy and X-ray spectral analysis in cases of possible lethal volatile inhalation may prove useful adjuncts in determining the type of substance inhaled and in providing evidence of previous non-lethal episodes.

Multi-organ toxicity and death following acute unintentional inhalation of paint thinner fumes

BACKGROUND

Paint thinners containing a mixture of volatile organic solvents have considerable potential for solvent abuse. Deaths from solvent inhalation have been reported but most of them relate to intentional solvent abuse and occur soon after exposure. Accidental death due to unintentional inhalation of solvent vapors can also occur suddenly but more often, death results from late complications secondary to multi-organ toxicity. Malfunctioning of the cardiorespiratory, renal, and central nervous systems as a result of latent-toxic effects of solvent exposure has received little attention.

CASE REPORT

An adult male unintentionally inhaled an excessive amount of paint thinner vapors and immediately developed central nervous system effects, followed by severe cardiorespiratory and renal pathologies that ultimately led to death 11 days after exposure.

CONCLUSION

Acute unintentional inhalation of paint thinner fumes resulted in serious multi-organ toxicity and death. This case strongly suggests the need to employ suitable precautionary measures while handling volatile organic solvents in a confined area.

Inhalant misuse in youth: time for a coordinated response

Early adolescence is associated with high rates of experimental inhalant misuse, but only a minority continue to inhale on a regular basis. Inhalant misuse is associated with a range of adverse outcomes, including reports of increased morbidity and mortality. Research into inhalant use among adolescents is lacking, with limited data available on long-term outcomes or evidence-based approaches to treatment. Legislative and supply-reduction strategies have been introduced by a number of states and territories over recent years, but direct funding for specific targeted interventions is lacking. Investment and commitment to a national research framework, as well as coordination of local services, is urgently required.

The haematology of indigenous Australians

Prior to European settlement indigenous Australians were hunter-gatherers who lived in geographically isolated small clan groups, also separated by elaborate totemic rules. Today they still reside in isolated communities throughout Australia but many have moved to the cities. They share a high incidence of a range of health problems including cardiovascular disease, renal disease and infectious diseases largely attributed to a change to a more sedentary lifestyle. This paper reviews the haematology of indigenous Australians, including blood count, frequency and causes of anaemia, inherited risk factors for thrombophilia, blood groups and the incidence and types of haematological malignancies. There are some significant genetic differences between indigenous and non-indigenous Australians particularly in the frequency of blood groups, factor V Leiden and prothrombin mutations and presence of -alpha3.7 kb thalassaemia. These findings may have practical therapeutic implications (e.g. HPA phenotype for transfusion therapy and pregnancy risk) and in predicting disease risk. Other differences are acquired, related to lifestyle and living conditions (e.g. eosinophilia secondary to parasitic infections; iron and folate deficiencies), and are largely preventable.

Petrol sniffing in Aboriginal communities: a review of interventions

Petrol sniffing (and other forms of inhalant misuse) occur within some Aboriginal communities across Australia. However, there is little documented information about the nature and combination of interventions that are most effective in addressing it. This article reviews published and unpublished literature relevant to petrol sniffing in Australian Aboriginal communities. A range of strategies which have been trialled previously are discussed under the categories of primary, secondary and tertiary intervention. We have adopted Zinberg's schema of 'drug', 'set' and 'setting' in theorizing the mix of interventions most likely to reduce petrol sniffing. We argue that interventions should address as many as possible of these factors. Further, while no strategy is likely to succeed without strong support from local community members, governments also have an important role in addressing petrol sniffing. Consistent funding for strategies directly addressing petrol sniffing and co-ordinated government responses to the broader needs of Aboriginal young people and their communities are critical.

Determination of urinary hippuric acid in toluene abuse

BACKGROUND

Volatile substance abuse is practiced mainly by adolescents and young adults. Its effects are central nervous system excitation followed by central nervous system depression, at times accompanied by seizures. It may cause sudden death as a result of ventricular arrhythmias, reflex vagal inhibition, respiratory depression, and anoxia. Chronic toxicity may involve the nervous system, heart, kidney, and liver. Toluene-based adhesives are among the most commonly inhaled substances.

CASE REPORT

A 14-year-old female presented with confusion, hallucinations, and intermittent laughing and crying after having inhaled contact glue several times daily in the course of 5 days. Her condition improved within 3 h. Urinary hippuric acid was 93.9 g/g creatinine indicating heavy toluene exposure (biological exposure index, BEI, is 1.6 g/g creatinine).

CONCLUSION

In this patient, urinary hippuric acid was a biomarker for her toluene abuse.

Deaths associated with inhalant abuse in Virginia from 1987 to 1996

Inhalant abuse has existed for a considerable period of time and it is currently one of the most prevalent drug abuse problems in the world. One repercussion from using these compounds is that abuse may result in lethality. In an attempt to better understand the deaths associated with inhalant abuse, the authors surveyed the death records from the Commonwealth of Virginia from 1987 to 1996. Examination of the state records identified 39 deaths related to inhalant abuse during this time period. While no significant increase or decrease in the death rate was observed across the time period investigated, all regions of Virginia were affected, with the rates being highest in the northern and eastern regions of the state. Age of death ranged from 13 to 42 years with the majority of deaths (70%) occurring at 22 years of age or younger. Ninety-five per cent of the individuals were male, with volatile substance abuse deaths accounting for 0.3% of all deaths in males aged 13-22 years. The chief volatile substances used were gas fuels (46%), predominately butane and propane, chlorofluorocarbons (26%), chlorinated hydrocarbons and alkylbenzenes (21%), and other volatile substances including volatile anesthetics. Deaths associated with the abuse of butane and toluene were more likely to be traumatic, but all substances appeared capable of killing directly by their toxic effects, probably through cardiac and/or respiratory mechanisms. The ramifications of these findings for regulation and prevention are addressed.

Reputations, self-concepts and coping strategies of volatile solvent users

Data pertaining to the reputations, self-concepts and coping strategies of thirty-one secondary school Volatile Solvent Users (VSUs), forty-four ex-VSUs, and forty-eight non-VSUs in the Perth Metropolitan area of Western Australia were obtained using the High School Student Activity Questionnaire. Findings revealed that significant differences between current VSUs, ex-VSUs, and non-VSUs were more attributable to factors of reputation enhancement than to factors of either self-concept or coping strategies. Current VSUs identified themselves as both having and wanting to have a more non-confronting reputation, and as admiring drug-related activities significantly more than both ex-VSUs and non-VSUs. Two coping variables were also found to be significant indicating that females use more non-productive coping strategies and external coping strategies than males. No interaction effects were identified. The implications for drug education and further research are discussed.

An evaluation of unleaded petrol as a harm reduction strategy for petrol sniffers in an aboriginal community

OBJECTIVE

In mid 1989, leaded petrol was replaced by unleaded petrol to reduce lead toxicity in petrol sniffers in Maningrida, a remote Aboriginal community in Northern Australia. RETROSPECTIVE REVIEWS: Hospital admissions between 1987 and 1992 due to petrol sniffing were compared for Maningrida and a community using only leaded petrol.

RESULTS

Admissions from Maningrida decreased significantly following introduction of unleaded petrol (chi 2 on 2df = 22.25, p < 0.001). Lead and hydrocarbon exposures were also compared for three groups from Maningrida (27 sniffers using only unleaded petrol; 15 exsniffers and 13 nonsniffers) and 24 individuals admitted to hospital for petrol sniffing related illness from other communities using only leaded petrol. Median blood lead levels for hospitalized sniffers (using only leaded petrol). Maningrida sniffers (using only unleaded petrol), exsniffers and nonsniffers were 5.06, 1.87, 1.24 and 0.17 microM/L respectively. There were significant differences between blood lead level, delta-aminolevulinic acid dehydratase activity, and free erythrocyte protoporphyrin for sniffers of leaded and unleaded petrol, whereas these indices were not significantly different for current sniffers and exsniffers in Maningrida. Hydrocarbons were only detectable in the blood of active sniffers (toluene < or = 0.5 micrograms/mL; benzene < or = 0.17 micrograms/mL blood; n-hexane not detected).

CONCLUSIONS

The elimination of tetraethyl lead from petrol resulted in a significant decrease in hospitalization of petrol sniffers.

Severe burn injury from recreational gasoline use

This report describes the case of a 13-year-old boy who suffered severe burns with inhalation injury during the recreational use of gasoline. Gasoline sniffing is a popular form of solvent abuse for young children and adolescents in isolated, rural communities. In addition to the neurological and physiological complications of gasoline inhalation, gasoline sniffers face the significant threat of severe burn injury or death resulting from ignition of the gasoline vapor as well as from extensive physical contact with the constituents of liquid gasoline.

Strain-dependent variability in nitrous oxide withdrawal seizure frequency

Exposure to nitrous oxide produces handling induced convulsions following withdrawal in mice. Since strain differences in responsiveness to the antinociceptive potency of N2O have been found, we examined whether there were differences in susceptibility to N2O withdrawal seizures. Significant differences were found between mouse strains, varying between 100% and 0% of mice exhibiting withdrawal seizures. There was a lack of correlation between the sensitivity of the mouse strains to N2O-induced analgesia and N2O withdrawal seizures, suggesting different mechanisms of action.

Abuse of inhalants: a review

Inhalants, a chemically heterogeneous group of psychoactive substances found in adhesives, lighter fluids, spray paints, cleaning fluids and typewriter correction fluid, may be used by up to 10% of young people. This article reviews the health effects, epidemiology, risk of other substance use and addiction and psychiatric co-morbidity associated with the practice of inhalant use.