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Alcohol is a drug (see Chapter 2) that is often used with other drugs, ranging from simple combinations, such as alcohol and nicotine at one end of the spectrum, to multiple combinations at the other end. Drugs may be used concurrently with alcohol, as a substitute for it, or in response to withdrawal from it. It is important to clarify how and why they may be used together (e.g., to heighten positive experiences or minimize negative ones). In the clinical situation, one may see alcohol dependent patients who report that they have been abstinent from alcohol for some considerable time, but this “abstinence” has been achieved by substituting another drug such as benzodiazepines or cannabis, or both. The patterns of relationship that can exist between the uses of different types of drugs are myriad, and the following case extract illustrates one variation on this theme:
The patient was a successful businessman, aged 35. His working day was lived at a fast pace, and most evenings were spent entertaining business associates in restaurants and nightclubs. He and his guests would get through a lot of alcohol, drinking on average a couple of bottles of wine each as well as “a few” double vodkas. Although he said he might not be as sharp as he would like, rarely did he become, in his terms, “pretty incoherent.” However, he was beginning to feel “dreadful, sick, sweaty” on most mornings, and occasionally he would be unable to remember how he had reached his bed. Cocaine then began to be available in his social circle, and, before long, he discovered that this drug appeared to provide an antidote to some of the unwanted effects of alcohol. For instance, if he snorted (sniffed) cocaine a few times during the evening, “it lifted me up, I could go on drinking, it stopped me from passing out with the alcohol.” He also found that a line or two of cocaine helped to alleviate the unpleasant early-morning symptoms caused by the previous night’s drinking. Within a few months, he progressed from snorting to smoking crack cocaine, and his cocaine use rapidly and disastrously went out of control. His problem came to attention when he was arrested for possession of cocaine. Seen by a doctor at the request of his solicitor this man said: “OK, I’m addicted to cocaine but alcohol is not a problem.”
This patient’s history illustrates how another drug often lies behind the immediately presenting drug. It would be unprofitable in such circumstances to debate whether alcohol or cocaine was the “real” problem. This man’s problem was his tendency to misuse substances. Both the alcohol and cocaine aspects of his history have to be taken seriously, but what the patient himself and those who are seeking to help him need to realize is that dependence can often resemble the many headed Hydra of mythology: one head can be lopped off and two grow in its place. With such a patient, unless there is a focus on the central issue of his tendency to develop dependence on substances, the story will all too probably progress in terms of a further switching or mixing of different substances – in terms perhaps of tranquillizers or sleeping tablets then being added to alcohol.
This chapter describes some of the more frequently encountered connections between alcohol and other drug use (Table 7.1). It also considers the general implications both for prevention and for clinical practice that stem from the realization that alcohol and other drug problems potentially constitute one continuous domain rather than two distinct problem areas. Services may be set up or commissioned to manage alcohol problems without necessarily being skilled in or expected to deal with an individual’s use of other substances. However, given the prevalence of polydrug use, all services should be able to manage all drug misuse or at least refer to and work collaboratively with another service.
Polydrug use
Polydrug use has become increasingly the norm over recent decades, even without including tobacco smoking. It occurs in the general population and is not confined to individuals heavily involved in the “drug scene” or in contact with treatment services. It has been accentuated by the rising availability of prescribed, abusable drugs, most notably opioids and benzodiazepines. Many factors are implicated in the initiation and perpetuation of other drug use in people who have drinking problems, and these can be considered under general headings such as psychological, socioeconomic, pharmacological, and genetic–environmental. Such factors do not occur in isolation but are often multiple and interrelated.
Polydrug use has been defined by the World Health Organization (1994) as the consumption of more than one psychoactive drug or drug class at the same time (concurrent use) or in succession (sequential use). Various patterns may exist for any given alcohol–drug combination. Assessment should tease out the relationship between alcohol and other drug use and how it may change during treatment. The interaction of alcohol with other drugs involves multiple risks of which patients should be made aware, most notably the potential for fatal respiratory depression from combined opioid and alcohol use (or heroin, alcohol, and benzodiazepines).
Polydrug use serves a number of purposes (Leri, Bruneau, & Stewart, 2003). Some drugs can enhance the effect of others, counteract or attenuate negative effects, or can be used as a substitute for another drug when it is not available. For instance, alcohol can enhance the effects of stimulants such as cocaine and amphetamines, and also the effects of benzodiazepines and volatile solvents. Alcohol can also reduce the jittery feelings associated with stimulant use and moderate the symptoms of the withdrawal phase or “crash.” A heroin user may substitute with alcohol, cannabis, or benzodiazepines, either alone or in combination, to tide them over until heroin is again available. Thus, combinations and patterns of polydrug use vary according to the characteristics of users, the availability of drugs, peer influence and fashion, the context of drug use, and prescribing practices (European Monitoring Centre for Drugs and Drug Addiction, 2009). Consuming several drugs is not necessarily done in a haphazard fashion. Users make take drugs in a particular order and at particular relative doses specifically to achieve a desired effect. Aside from each drug interacting with the brain’s chemistry to produce its effects, such polydrug use may also affect the pharmacokinetic properties of other drugs (e.g., augmenting plasma concentrations; Barrett, Darredeau, & Pihl, 2006). Although particular combinations may be seen quite commonly, some groups of patients (e.g., addicted healthcare professionals) may use rarer combinations because of their privileged access to a wide range of drugs.
Polydrug use can lead to significant medical, neuropsychological, and psychosocial complications, and thus it has a significant impact on public health. It is associated with increased risk-taking behaviours in multiple domains, thus increasing the risk of negative outcomes ranging from road traffic accidents to contracting and transmitting HIV, hepatitis, and other sexually transmitted infections. For instance, in UK HIV services, illicit drug use is associated with problem drinking and risky sexual practices (Daskalopoulou et al., 2014). Heavy drinking in former or current illicit drug users is common and is associated with a range of adverse health consequences. This is particularly true for those who are hepatitis C positive, in whom drinking may prevent the individual from being allowed to start treatment and may also increase damage to the liver. Most drug-related attendances to Emergency Rooms involve polydrug use, in particular the combination of alcohol and prescription drugs (McCabe, Cranford, & Boyd, 2006). Polydrug users are more likely to have psychiatric comorbidity (see Chapter 6).
In developed Western countries, alcohol and nicotine is the most common polydrug combination, followed by the addition of cannabis. This is particularly seen in younger people. For instance, in Kelly and colleagues’ (2014) recent survey of 18- to 29-year-old Australian drinkers, the majority used alcohol only (51 percent), and 37 percent also smoked tobacco but had no other drug use. The remainder used alcohol, tobacco, and also illicit drugs. Kelly et al. noted that this profile had not changed substantially in the past half-decade. In South London residents over the age of 16, similar findings have been reported, with alcohol, cigarettes, and cannabis associated with the highest probability of polydrug use (Carter et al., 2013). A UK-wide study also reported that hazardous alcohol use and tobacco use were strongly associated with illicit polydrug use and that polydrug use was associated with adverse mental health outcomes, including suicide attempts (Smith, Farrell, Bunting, Houston, & Shevlin, 2011).
Similar patterns of polydrug use have been described in the United States. In addition to the use of alcohol, the use of cannabis and tobacco before the age of 16 was associated with problematic use of substances, including misuse of prescription drugs (Moss, Chen, & Yi, 2014). Another survey of adults revealed that about 10 percent of current drinkers also used cannabis in the past 12 months, with 7 percent using them together; tobacco use was not assessed (Midanik, Tam, & Weisner, 2007). Using alcohol and cannabis together was strongly associated with depression, alcohol dependence, and adverse social consequences. Interestingly, using both substances in the past 12 months but not at the same time was only associated with depression. This emphasizes that the impact of concurrent use may differ from sequential use due to drug interactions, an area that receives little research attention. After cannabis, the next most common group of drugs used were prescription painkillers, followed by illicit drugs such as cocaine. Other U.S. studies have reported the most common two-drug combinations are alcohol with either cocaine, cannabis, opiates, or sedatives (Kedia, Sell, & Relyea, 2007; Martin et al., 1996; Staines et al., 2001; Substance Abuse and Mental Health Services Administration, 2002).
These studies also illustrate that although cannabis has often been seen as the “gateway drug” (i.e., its use leads to further illicit drug use, such as heroin or cocaine), in fact use of tobacco or alcohol generally precedes cannabis use.
Many other drugs are used in combination with alcohol, including over-the-counter (OTC) medicines like paracetamol (acetaminophen) and the nonsteroidal anti-inflammatory drug (NSAID) ibuprofen. NSAIDs are associated with gastritis (inflammation of the stomach lining), as is alcohol, so this combination may result in indigestion/reflux and ultimately an ulcer and bleeding. Analgesics may help to relieve headache, musculoskeletal pain, or pain associated with pancreatitis or gout, but, after a time, simple aspirin and paracetamol/acetaminophen may not afford adequate pain relief, leading the drinker to progress to stronger analgesics, such as codeine or dihydrocodeine. High doses of analgesics can lead to both liver and renal problems, so the clinician should try to intervene before the patient – who may already have a compromised liver – ends up in intensive care with liver and renal failure.
Drinkers with chronic pancreatitis typically experience severe incapacitating pain and often seek opiate analgesia from their family doctor or hospital specialist. If these drinkers are economical with the truth or do not realize that their painkillers are opiate drugs, subsequent doctors may be unaware that they are obtaining such prescriptions for opioids. There is a real risk that when individuals with chronic pancreatitis or other chronic pain syndromes finally manage to become abstinent, they find that they are dependent on opioids.
Many drinkers complain of nonspecific pain in their joints, arms, and legs. It is important to take a history because the pain may have its origin in injuries sustained while intoxicated (e.g., due to a fist fight, a tumble down a flight of stairs, a violent alcohol withdrawal seizure, or an automobile accident). These patients may have little memory of the episode, relating, for instance, how “I woke up in intensive care with a mangled shoulder/leg/arm.” The perceived pain from such injuries can be compounded by long periods of self-neglect, poor diet, and lack of exercise, and also from alcohol-induced myopathy.
Prescription drugs are increasingly also available without a prescription via the Internet and are typically used in a manner not intended by a prescribing doctor. They are also widely stolen out of medicine cabinets or begged from friends and family. Problem or dependent drinkers often use OTC or prescribed drugs to obtain relief from chronic conditions such as insomnia, pain, and perceived stress.
Adolescents and polydrug use
As described previously, early use of drugs including nicotine and alcohol is associated with increased likelihood of use of additional drugs. Use of drugs in the young also raises concern about impact on the developing brain. In adolescence, the reward and motivation system develops early and is active, whereas the frontal lobes that control such behaviour do not fully mature until the early-to-mid 20s. The developing brain appears much more sensitive to the effects of drugs, and exposure during this age may lead to long-lasting changes in the brain’s connections.
The initiation of substance use in adolescents is heavily determined by environmental factors such as availability, price, social situation, peer group usage, and fashion (Han, McGue, & Iacono, 1999). Adolescents are prone to risk-taking behaviour. In moderation, this is part of healthy development. Indeed, adolescents who experiment a little are usually better adjusted as adults than are those who abstain completely. However, adolescent substance use is a powerful predictor of substance use disorders in adulthood (Grant & Dawson, 1997), and those with psychological traits such as impulsivity, alienation, and distress may be more vulnerable. Rates of tobacco, alcohol, and illicit drug use increase in the teenage years. Young people using one or more of these substances, especially alcohol, are more likely to use other substances subsequently. Teenagers with heavier drinking and smoking patterns are at greater risk of later drug use and dependence. Religious influences may help to attenuate the influence of substance use risk factors (Humphreys & Gifford, 2006). Drug fashions come and go, but alcohol is almost always implicated in the shifting picture of multiple substance use.
Recreational polydrug use is common in younger people in dance-club settings (the “clubbing scene”), and the drugs used here are typically alcohol, cannabis, and stimulants (including “legal highs”) (European Monitoring Centre for Drugs and Drug Addiction, 2009; see later discussion). In young people, cocaine use is prevalent, particularly in the Republic of Ireland and the United Kingdom, and, therefore, its use with alcohol should be assessed. One survey of Irish adolescents revealed that cocaine was often first used whilst intoxicated with alcohol (Apantaku-Olajide, Darker, & Smyth, 2013). This is consistent with evidence from other surveys and emphasizes the importance of targeting adolescent alcohol drinking.
Older adults and polydrug use
The challenge of managing polydrug use in an increasingly elderly population is only beginning to be realized. Referred to as “invisible addicts” in a recent report, it was emphasized that mortality rates linked to drug and alcohol use are higher in older compared with younger people (Crome et al., 2011). There are also high rates of mental health problems in older people including, in particular, cognitive disorders. In this population, prescribed medication for a range of physical health problems is the norm. In addition, individuals may buy OTC medications as well as use a combination of licit and illicit substances. Such polypharmacy creates increased risk and a clinical challenge. Careful assessment is required to assess all possible licit, illicit, prescribed, and OTC drug use, and gentle but persistent questioning may be required.
The reasons underpinning starting substance misuse in later life are likely to include loss of a job, bereavement (e.g., of a spouse), retirement, or medical problems. Prognosis is generally better than for those with an earlier onset, but careful assessment is advisable before concluding that a late-life problem is truly new versus being an exacerbation of a long-standing but milder problem or one that can no longer be hidden (e.g., daytime drinking no longer being concealable from a spouse once the person has retired).
Specific drugs used by patients with drinking problems
The evidence base on the use of alcohol in combination with other drugs is better developed for epidemiologic research than for treatment research because substance use disorder treatment studies often focus on patients who have difficulties with only one substance (Connor, Gullo, White, & Kelly, 2014; Humphreys, Blodgett, & Roberts, 2015). The next section thus puts more weight on the former, although some comments regarding treatment management are also offered. A more extended discussion of treatment strategies in presented in Chapter 13.
Alcohol and nicotine
As described, alcohol use and tobacco smoking is the most common substance use combination. Several psychological and neuropharmacological models have been proposed to explain the association between alcohol use disorders (AUDs) and tobacco smoking. Clinical and preclinical models have shown that use of either alcohol or nicotine may increase use of the other, and each can act as a conditioned cue for the other substance (McKee & Weinberger, 2013). Nicotinic receptors are key modulators of the dopaminergic reward mesolimbic system, and it has been suggested that the synergistic effects of alcohol and nicotine are due to their combined effect on this system. There may also be a common genetic vulnerability (Daeppen et al., 2000; Madden & Heath, 2002).
In general population epidemiological surveys, about 50 percent of alcohol dependent individuals smoke versus more than 80 percent in treatment populations (Kalman et al., 2011; McKee & Weinberger, 2013). Among smokers, alcohol dependence is 10 times more common than in nonsmokers. Nicotine dependence is associated with a greater severity of alcohol dependence and alcohol-related problems. Alcohol dependent individuals who smoke have high rates of tobacco-related disease, and they are more likely to die from tobacco-related disease than from their alcohol dependence. Some disorders are more common in those problem drinkers who also smoke, such as head and neck cancers, cirrhosis, and pancreatitis (Pelucchi et al., 2006). In addition, both alcohol and nicotine dependence are associated with mood and anxiety disorders (Le Strat, Ramoz, & Gorwood, 2010).
As described, cigarette use is strongly associated with alcohol and other drug use in adolescents. Such adolescents have an increased risk of having difficulties at school, delinquency, and use of other drugs (Myers & Kelly, 2006). Young adults who smoke are also more likely to report binge drinking (McKee & Weinberger, 2013). Young people who are treated for alcohol and other drug use are typically heavy smokers, and smoking tends to persist after treatment.
There is a wealth of evidence and guidelines about stopping tobacco smoking (e.g., Fiore et al., 2009; Lingford-Hughes, Welch, Peters, Nutt, & BAP Group, 2012; NICE, 2013) but little for comorbid alcohol use and tobacco smoking. In part, the problem stems from tobacco cessation researchers having the disappointing habit of excluding patients with drinking problems from clinical trials (Lembke & Humphreys, 2015), which leaves clinicians in the dark about how to handle this common comorbidity.
Many people take the approach of “one vice at a time” when thinking about dealing with their tobacco smoking and problem drinking. However, given that use of one drug can increase the use of the other and that use of either drug can trigger relapse among individuals who have stopped using the other, is it better to give both up simultaneously? Alcohol dependent individuals are open to advice on smoking (Harris et al., 2000). In discussing what approach to take with a patient, clinicians should explore how they smoke and drink; for example, always together? Or, if the patient cannot drink, do they smoke more? Given the adverse health consequences, all patients who smoke should receive advice about quitting smoking or at least reducing. There are reports of increased smoking to compensate for not drinking, so this should be monitored. A meta-analysis of concurrent tobacco and alcohol treatment compared with alcohol-only treatment reported higher abstinence rates from alcohol with concurrent treatments (Prochaska, Delucchi, & Hall, 2004). Smoking cessation interventions have been reported to result in low quit rates in alcohol dependent individuals. However, these trials were primarily done prior to widespread smoke-free policies. In-patient units are now smoke-free, and nicotine replacement therapy (NRT) can be offered during the course of the medically assisted withdrawal programme and thereafter. The spread of smoke-free policies in places where people drink (e.g., pubs, restaurants) may have contributed to a reduction in the onset of alcohol abuse in the population and reduced drinking by heavy drinkers (McKee & Weinberger, 2013).
The use of e-cigarettes containing nicotine (they can also be used to consume cannabis) is increasing, both by those using it as a substitute for smoking when in smoke-free areas and by those trying to quit. Because e-cigarettes are seen as safe, some may start to use them who otherwise would not have started tobacco smoking, including adolescents. The debate about regulations that should be in place for e-cigarettes is under way. The relationship between e-cigarettes and alcohol abuse is not yet clear.
Whilst counselling with or without NRT is the most common approach to quit or reduce tobacco smoking, there are other medications available. These all have been shown to be effective (Lingford-Hughes et al., 2012; NICE, 2013). Bupropion, an atypical antidepressant that is licensed as an aid for smoking cessation, has been shown to be effective in a few small studies, including those enrolling individuals with a history of major depression and alcoholism (Hayford et al., 1999) and recently abstinent alcohol dependent individuals (Karam-Hage, Strobbe, Robinson, & Brower, 2011). Adding bupropion to a nicotine patch did not improve smoking outcomes in abstinent alcohol dependent individuals (Kalman et al., 2011) compared with nicotine patch alone. Varenicline is another medication shown to be effective in smoking cessation (Lingford-Hughes et al., 2012; NICE, 2013). It is a partial agonist at the alpha4beta2 nicotinic receptor that modulates the mesolimbic dopaminergic reward pathway as well as processes involved in memory and learning. Varenicline has also been investigated as a treatment for alcoholism and could therefore have particular utility in comorbid alcohol and nicotine dependence (Nocente et al., 2013).
Alcohol and stimulants
The combination of alcohol and a stimulant such as cocaine, amphetamine, methamphetamine, or ecstasy is a not uncommon pattern of polydrug use. For instance, cocaine use in heavy drinkers increases the risk of developing alcohol dependence fourfold, with more frequent cocaine use associated with more rapid progression (Rubio et al., 2008). Greater alcohol use and greater levels of psychological problems are seen in those who are alcohol dependent and use cocaine (Heil, Badger, & Higgins, 2001). Similarly, in young people, it has been reported that alcohol is used in greater quantities with cocaine than when it is used alone (Barrett et al., 2006). Binge drinking in young people is associated with stimulant intoxication, where the stimulant could be cocaine, ecstasy, amphetamine, or methamphetamine (McKetin, Chalmers, Sunderland, & Bright, 2014).
Cocaine may be taken by different routes, such as snorting it in powder form, injecting liquefied cocaine, or smoking “crack cocaine.” Generally, the use of crack cocaine is associated with a higher degree of physical dependence on the drug. Those who smoke crack cocaine and drink alcohol tend to be older with lower education and employment levels compared with those who snort cocaine and drink alcohol (Gossop, Manning, & Ridge, 2006). Improving sociability has been cited as a motivation for concurrent alcohol drinking and snorting cocaine but not for smoking crack cocaine (Martin, Macdonald, Pakula, & Roth, 2014).
Whereas much concurrent use may be unplanned, alcohol and stimulants may be used together intentionally for a variety of differing reasons. Consuming alcohol during a cocaine binge may prolong the euphoriant effects of cocaine, diminish the unpleasant experiences associated with cocaine use (e.g., agitation and paranoia), provide sedation, and ameliorate the dysphoria associated with withdrawal and early abstinence from cocaine (the “crash”). Alternatively, cocaine or other stimulants such as amphetamine appear to attenuate the intoxicating and sedative effects of alcohol, thus allowing drinkers to drink more alcohol and tolerate these considerable quantities without becoming obviously intoxicated. The Friday night drinking session can be extended over a weekend and only comes to an end on Sunday night as the working week looms nearer. Once regular cocaine and alcohol use is established, it may be difficult to give up one substance without giving up the other because alcohol can become a powerful conditioned cue for cocaine.
Cocaethylene, a pharmacologically active metabolite, is formed when cocaine and alcohol are taken together. It enhances and extends cocaine-induced euphoria and also increases heart rate and blood pressure. Cocaethylene is formed in the liver and, not surprisingly, greater levels are formed from taking cocaine orally compared with routes with less hepatic involvement (i.e., injecting or smoking; Herbst et al., 2011).
For many patients, treatment of the cocaine problem leads to an improvement in the alcohol problem. However, the presence of alcohol problems and dependence in treated cocaine users is associated with more severe dependence, poorer retention in treatment, and a poorer outcome compared with either disorder alone (Brady et al., 1995; Carroll, Power, Bryant, & Rounsaville, 1993; Carroll, Rounsaville, & Bryant, 1993). Because no medication has been robustly shown to treat cocaine addiction, psychosocial interventions such as contingency management are the mainstay of treatment (Lingford-Hughes et al., 2012). There is limited evidence to guide what might be the best course of treatment for comorbid alcohol and cocaine misuse. Treatment with disulfiram for 12 weeks was reported to be associated with better treatment retention and abstinence, particularly when combined with “active” out-patient psychotherapy (cognitive behavioural coping skills and therapy) and 12-step facilitation (Carroll et al., 1998, 2000; Lingford-Hughes et al., 2012). Disulfiram in combination with naltrexone has been shown to be more likely to result in abstinence from cocaine and alcohol, although the difference was not statistically different from either drug alone in this trial, and adherence was low (Pettinati et al., 2008).
Alcohol and cannabis
Cannabis is the most commonly used drug worldwide after alcohol and nicotine. As its legal status and availability changes in some parts of the world, it will be interesting to see how cannabis use alters in response. The main intoxicating effects of cannabis are due to delta-tetrahydrocannabinol (THC). “Skunk” and butane hash oil are particular forms of cannabis with higher THC levels. Simultaneous use of alcohol and cannabis is common in adolescents, and this may have detrimental effects on brain development including predisposition to more severe cannabis- or alcohol-dependence symptoms. Alcohol and cannabis may alter each other’s absorption, although evidence is mixed on whether the combined impact on impairment (e.g., driving ability) is multiplicative or additive (Hartman et al., 2015; National Highway Traffic Safety Administration, 1999). Simultaneous use can sometimes be unpleasant, with individuals experiencing nausea, vomiting, dizziness, and sweating. This most likely occurs because alcohol speeds up the absorption of THC, leading to a stronger cannabis effect. Alcohol and cannabis are often used when “coming down” from ecstasy.
A number of synthetic cannabis-like compounds are available as “legal highs” via the Internet or through “head shops” (see the section on novel psychoactive substances). Often containing the name “spice,” some of these products appear quite potent and may have more than cannabis-like compounds in them. As with stimulants, psychosocial approaches are the mainstay of treatment of cannabis misuse. Cognitive-behavioural, motivational enhancement, and contingency management approaches can all be helpful for reducing use (Babor, 2004).
Alcohol and opioids
Alcohol and opioids can engage in a complex dance in the lives of those who use both simultaneously or at different times of life, as this case extract illustrates:
A 34-year-old unemployed man was referred for assessment of his heavy drinking and depression. He had experienced extreme emotional deprivation in childhood and had been in care. At 14, he began to drink beer and smoke cannabis “for comfort.” His daily alcohol consumption gradually increased to 3–4 cans of strong lager, and he began to experiment with mixing it with opioid medications that he stole from his parents’ and friends’ medicine cabinets. He first smoked heroin in his early 20s and very soon switched to intravenous use, sharing needles. He experienced multiple alcohol-opioid overdoses in his late 20s, including one that was nearly fatal. When he was 30, he entered a residential rehabilitation unit and gave up all illicit drug use. However, his alcohol consumption escalated, and, 4 years later, at the time of referral, his drinking was out of control. He was also experiencing a marked craving for heroin and was worried that he would begin using it again.
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