Priya G Menon1, Anjana Rani2, TS Jaisoorya3*
1Senior Resident, 2Assistant Professor, 3Associate Professor
Department of Psychiatry, Government Medical College, Ernakulam
*Correspondence: Department of Psychiatry, Government Medical College, HMT Colony PO, Ernakulam -683503 Email: firstname.lastname@example.org
Solvents, whose use is widely prevalent across the world, are one of the most common illicit drugs abused in Kerala, especially among the adolescents. However, few solvent users come in contact with the health care system due to their disenfranchisement and social isolation. This selective review outlines the current concepts and clinical management strategies related to solvent use and related disorders. No robust studies are currently available on treatment approaches, and all published treatment guidelines have been based on expert consensus. There are few case reports on use of baclofen, buspirone and lamotrigine in reducing craving and treating solvent dependence. Risperidone, haloperidol and carbamazepine are reported to be effective in the treatment of solvent induced psychosis. Recommended nonpharmacological approaches include cognitive, group, and behavior therapies. Many other aspects of solvent dependence, including course and outcome, have not been studied, despite the fact that use of solvents is associated with significant mortality, morbidity and psychosocial dysfunction. There is an urgent need for a concerted effort to develop effective evidence based interventions to tackle this issue.
Key words: Management strategies, selective review, solvent and related disorders
Solvent use among adolescents is a major concern across the world. Solvents are easily available, convenient to use, relatively inexpensive, and legal for certain uses; and all these factors promote their use in youngsters.1 In Kerala, though very few adolescents present to clinical settings with a primary complaint of solvent use, reports from the community, especially the teachers, suggest that experimental use of solvents is not uncommon. Though their use is under recognized, solvents have a high propensity to become a “gateway” for the use of other drugs, causing significant morbidity and mortality in all ages.2
Solvents are also called inhalants or volatile substances. The term inhalant refers to a wide variety of substances that are rarely, if ever, taken via another route of administration.3 The US National Institute on Drug Abuse (NIDA) classifies solvents into four categories:
Solvent use is the intentional inhalation of a volatile substance to achieve an altered mental state.
Hundreds of products containing a single solvent or a mixture of solvents that can produce intoxication if inhaled are commercially available with ease, making inhalants the fourth most commonly abused drug in the world.4 It is frequently the first drug to be tried by children, often as early as 10 years of age.4,5 In studies from the west, the prevalence was found to be highest among children, and to decrease as they reach late adolescence and early adulthood.3,5 Studies across countries place the prevalence in adolescents to be 6 - 11%, and that in people over 18 years to be 8 - 10%.3 According to the World Drug Report 2014, 0.4 - 6% of seekers for drug treatments worldwide were for solvent use.5
Studies on inhalant use from India are scarce, and are mostly case reports or series, mostly from street children, children from juvenile homes, attendees of deaddiction centers and school drop-outs.1,7,8 In a recent large study among students in high schools and colleges of Ernakulam, 2.4% reported sniffing of solvents, predominantly whiteners.9,10 Correction fluid (whiteners) has been reported to be the commonest inhalant abused in India, and the reasons cited for this include their low cost, easy availability, and legal use in homes, schools and offices.1,8 Like all drugs, motives for the use of solvents too include the need to have fun, get high, be part of a group, deal with problems,etc.4,7
Three patterns of use have been found for solvent abuse:11 Experimental use involves irregular use on a few occasions, is mostly seen in early adolescence, and is generally motivated by curiosity or peer pressure. Regular use involves the repeated use of solvents on more than a few occasions. This pattern is motivated by enjoyment or fun and is seen in late adolescence, mostly as a part of recreational or social group activity. Chronic use consists of long-term regular use which may even be daily use. Subjects would have developed multiple areas of problems/dysfunction by this stage.
Common methods of use are ‘sniffing’ or ‘snorting’ which involves the direct inhalation of fumes, ‘bagging’ from a plastic or paper bag, ‘huffing’ from a rag or cloth soaked in the substance held over the mouth or nose, ‘glading’ from air freshener aerosols, and ‘dusting’ which involves the direct spraying of aerosol cleaners into the mouth or nose. ‘Popping’ is the use of amyl nitrite by breaking the vials, causing a popping sound.
The intoxicating effects of solvents are exerted mainly through their CNS actions. Once sniffed, they are rapidly absorbed by the lungs, and enter the blood stream quickly with quick access to the brain.12,13 They are rapidly metabolized by the CYP 450 system. About one-fifth is excreted unchanged by lungs. Approximately 15–20 inhalations of 1% gasoline vapor produces effects within five minutes, and the intoxication can last from 30 minutes to several hours.13 Duration of intoxication may vary depending on the type and dose of the solvents, and is increased if they are used in combination with alcohol. Their CNS action is postulated to be mediated by hyperpolarization of the neurons by action at GABA receptors and inhibition of glutaminergic transmission involving NMDA receptors.12,13 The reinforcing effects are produced by modulation of mesolimbic dopaminergic activity.17 The nitrites, however, do not act directly on the CNS, and act primarily by dilating the blood vessels and relaxing the muscles, and are primarily used as sexual enhancers.3
Acute intoxication:In early stages, there will be a sense of euphoria or a ‘rush’, light-headedness, disinhibition, excitability, and impulsive behavior. Other symptoms can include nausea, vomiting, diarrhea, abdominal cramps, and coughing. Those who continue to inhale may experience blurred or double vision, dizziness, disorientation, drowsiness and headache. Higher dosages from prolonged use can result in visual hallucinations, loss of consciousness or death. Electrical excitability of the heart can become abnormal, and this can lead to fatal dysrhythmias.17 As the users can no longer inhale the solvents once they become drowsy with the increasing doses, coma and death due to intoxication are unusual.12
Withdrawal: Withdrawal from solvents is mild and self-limiting, and usually lasts only a few days.23 However, it may last up to a week in chronic users. The symptoms can include irritability, anxiety, depression, aggressive behavior, headache, sleep disturbances, tremors, dizziness, nausea and craving.17,20
Physical effects: Neurological toxicity is the most recognized and reported long-term side effect of inhaled solvent abuse.12,13 Chronic inhalant use also causes toxicity to several other organs, including the brain, heart, lung, kidney, liver, and bone marrow.12 Common long-term complications of chronic inhalant use are detailed in Table 1.
Table 1 - Adverse effects of inhalants12
Decreased Myocardial contractility
Hypoxia-induced heart block
Bone marrow suppression
Renal tubular acidosis
Psychosocial effects:Very few studies have looked into the psychosocial effects of solvent use. Available studies of adults indicate that inhalant users have higher rates of major depression, suicidal ideation and attempts, anxiety disorders and other substance use disorders than non-users.18,20 Children and adolescents who use inhalants have a very high risk of poly-substance use and psychiatric symptoms.22 They are also at a higher risk of earlier onset of behavior problems and antisocial conduct, and are more likely to drop out of school early, have estranged family relationships, be unemployed, socially isolated, homeless and have legal problems.20,21
Mortality: The leading cause of mortality in inhalant use is “sudden sniffing death syndrome”.17 This phenomenon is unrelated to frequency or pattern of use, and can occur even after the first inhalation. It happens due to the sensitization of myocardium to epinephrine by inhalants, which results in a fatal cardiac arrhythmia in the event of sudden stress or fright. Such deaths are unpredictable and unpreventable, and leave no post-mortem features.12,18
Inhalants can also cause death by various other mechanisms, both, acute and delayed, as detailed in Table 2.
Table 2: Causes of death in inhalant use
No laboratory tests are currently available to confirm a diagnosis of inhalant abuse. The clinical diagnosis relies almost entirely on reliable informants, thorough history taking, and a high index of suspicion.21,27 The easiest way to distinguish between the use of inhalants and other drugs is the smell. Inhalants generally leave a characteristic unpleasant odor on the breath and clothes. People who inhale paint (‘chromers’) may also have traces of paint on their face and clothes. Attention must also be paid to other signs and symptoms commonly associated solvent abuse, listed in Table 3.
Paint or oilstains on body or clothing
Chemical odour on breath
Spots or sores in or around mouth
Dizziness or unsteady gait
Forgetfulness or difficulty concentrating
Anorexia or nausea
Irritability or excitability
Table 3:Signs and symptoms of inhalant abuse35
The following methods may be followed for a patient suspected of using solvents:
Brief screen: The aim here is to quickly gather information about the solvent user, especially in emergency services. Areas of assessment can include:
Full assessment: This is generally done in inpatient settings, with the aim of gathering information that will help in developing comprehensive plans for management and follow-up. In addition to the aspects described in the brief screen, the following factors too need to be assessed:
Screening questionnaires: The Volatile Solvent Screening Inventory (VSSI) and Comprehensive Solvent Assessment Interview (CSAI) are commonly used.22 Though they are available for free and assess the various aspects of inhalant use, they are quite complex for use in routine clinical practice.
Laboratory studies: Specific toxicology tests are not available in most laboratories. The results may take from several days to weeks to be available, and hence are not useful for immediate diagnosis. Gas chromatography can detect most volatile agents within 10 hours of exposure; but the procedure is not practical for routine use and is unavailable in most settings.14 Consequently, a thorough history and physical examination are usually more helpful than toxicological screens. Toluene can be detected by checking for Urinary Hippuric Acid (UHA), but the results have to be interpreted in relation to blood toluene levels.14
To assess the extent of damage due to long-term inhalant use, tests like full blood count, liver function tests, renal function tests, electrolyte levels, thyroid function tests, creatine kinase, EEG and brain imaging can be used.12,27
In spite of the high rates of solvent use reported, especially in deprived communities, the social/geographical isolation and the presence of poly-substance dependence and comorbid psychiatric disorders make solvent users an extremely difficult group to recruit and follow-up for research. The recent Cochrane review on solvent abuse reported that no recommendations with regards to pharmacological treatment can be made owing to lack of robust studies.21 Evidence base of treatment guidelines published elsewhere has been based on case reports and case series. Clinicians need to be aware of the restricted evidence base of currently available treatment recommendations while considering the suggestions provided here.
Medical attention is usually sought in acute intoxication only when there are serious injuries or other threats to life. No medications currently available can reverse acute inhalant intoxication. Fortunately, the intoxications resolve spontaneously with supportive treatment. A patient suspected to be in acute intoxication needs to be monitored in a clinical setting, in close observation, for approximately 2-4 hours. They should not be left alone for up to 24 hours even if there are no serious symptoms, and for a longer period if symptoms like seizures or impaired consciousness are present. Management should be in a quiet setting and should involve the following strategies:
The typical 28-day inpatient treatment programs conventionally used for other drugs is probably too short a period to create some realistic changes in solvent users. They seem to respond best to a program that includes an extended detoxification or “treatment readiness” period that requires more than 28 days.27,28 Since inhalant use is rarely an isolated issue, it must be dealt with in the context of other psychosocial factors. Thus the treatment programs must be coordinated, and prepared to use all community resources after building a fundamentally strong therapeutic relationship with the patient.
Pharmacological approaches: Isolated studies provide preliminary support for the use of baclofen, started at 10mg/day and gradually increased to 50mg/day over one week, to be beneficial in the management of craving and withdrawal and possibly in relapse prevention in patients with dependence.24 An isolated report suggested that buspirone, at 40 mg per day for two months, was effective in relieving craving for inhalants.30 Isolated studies suggest efficacy of lamotrigine 100 mg daily for six months and vigabatrin in dependence.25,26 Risperidone 1 mg twice daily was found to reduce both craving for inhalants and paranoid ideation, and to maintain abstinence for 12 weeks.29
Induced psychosis with severe agitation will require cautious control with haloperidol.19 Case reports also suggest that carbamazepine can be used as first-line treatment for inhalant-induced psychotic disorder, particularly for patients without high levels of psychomotor agitation. For patients with more severe behavioral disturbances, carbamazepine may be initially used, with intermittent use of an antipsychotic to control agitation. Although it remains to be demonstrated that such an approach would enhance efficacy, it would likely reduce adverse effects.19 However, few reports suggest that psychosis is repaired with abstinence and time alone.34 Antidepressant medications are not useful in the acute phase of the disorder, but they may be of use in managing coexisting anxiety or depressive illnesses.16
Psychological Approaches: The most important aspect of any psychological approach employed would be to establish rapport and therapeutic relationship with the subject, and this can be extremely difficult with solvent users. However, it would be useful to keep an open and nonjudgmental style during assessment to facilitate openness and honesty. Start the discussion by exaggerating the amount the subject may be possibly using, thus indicating that you are open to the subject using a lot(top-high approach). It is important to monitor the client’s comfort with the level of disclosure throughout the interview.27
Brief interventions: Brief interventions are generally opportunistic interventions for clients who have not consulted specifically for solvent use but whose use is detected to be risky.24,33 They can be completed within 15-20 minutes, with success closely linked to ensuring of follow-ups.
FRAMES is one of the most widely used brief interventions. It was initially formulated as a brief intervention strategy for alcohol use.33Its components include feedback, responsibility, advice, menu of options, empathy and self-efficacy. Various trials have shown these components to be effective in reducing harmful use of various substances.28,31,33
Long-term psychological approaches: All psychological approaches with proven effectiveness in other substance use disorders, including motivational interviewing, cognitive behavior therapy and group therapy, have been tried with this population, mainly with the goal of addressing the maintaining factors of inhalant use.27,28,32 All these techniques are reported to have some benefit, though the change can be very slow and incremental.24 Any of the above approaches may be tried, but should include the aspects outlined below:
Treatment usually lasts 3-12 months. Treatment termination is considered successful if the youth has practiced a plan to stay abstinent, is showing fewer antisocial behaviors, has a plan to continue any needed psychiatric treatment and live in a supportive drug-free environment, is interacting with the family in a more productive way, is working or attending school, and is associating with drug-free non-delinquent peers.27,28
As in all addictive behaviors, preventive approaches in the form of a community based intervention could be an equally effective strategy to tackle solvent use too. Supply reduction strategies of restricting sales and product modification have been advocated. Legal measures, including community policing, have been shown to be helpful. But a comprehensive community based strategy involving intersectoral partnerships among legislating agencies, retailers, manufacturers and community agencies, both governmental and private, has still not been implemented anywhere in the world. There is thus an urgent need for a concerted effort to improve awareness among various stake-holders to comprehensively tackle this growing issue.