Benzodiazepines and hypnotics

Although a reduction of benzodiazepine use had been demonstrated in community settings (Reference Schmidt, Claesson and WesterholmSchmidt 1998), improved recognition of anxiety disorder and reduction in the use of atypical antipsychotics have led to a renewed increase in the use of benzodiazepines. In a nationally representative British sample of people aged 65 or older (Reference Morgan, Dallosso and EbrahimMorgan 1988), the prevalence of hypnotic drug use was 16%. The rate of use was 13% among people aged 65–74 and 20% among those aged 75 or older. Durations of use were from 1 to 5 years in 13% of the sample, from 5 to 10 years in 19% and for more than 10 years in 25%. Among the benzodiazepine users 71% reported daily use and 77% reported that they had been taking benzodiazepines for at least 2 years.

Although addictive potential for zopiclone has been suggested to be less than for benzodiazepines, there are case reports of emergence of addiction. Hence, caution should be taken when prescribing this agent for insomnia (Reference CimolaiCimolai 2007). Although there has been a surge in the use of non-benzodiazepine sedative hypnotics (such as zopiclone), benzodiazepines and opioid analgesics continue to be the commonly misused drugs among older adults (Reference BlowBlow 2001).

Reference HiggittHiggitt (1988) demonstrated that in elderly people, depending on the pharmacokinetics of the particular benzodiazepine, physical dependence could arise without dose escalation. The duration of treatment, higher dose level, shorter pharmacokinetic half-life and higher milligram potency of the agent are associated with increased risk of benzodiazepine dependence.

Patient factors include prior or concurrent alcohol dependence or sedative drug dependence, chronic insomnia as the target symptom for which the drug is prescribed and coexisting chronic painful physical illness or personality disorder. In Reference Lechevallier, Fourrier and BerrLechevallier et al (2003) use of benzodiazepines was associated with symptoms of depression or anxiety (women: odds ratio OR = 2.6; men: OR = 4.4) and with regular use of at least three non-psychotropic drugs (women: OR = 2.0; men: OR = 1.8). Reference Fernandez and Cassagne-PinelFernandez & Cassagne-Pinel (2001) have suggested that benzodiazepine addiction in elderly people acts as psychological/existential medical care.

Opioids and cocaine

In a study of elderly primary care patients on low-dose opioid analgesics for a year, 40% met ICD–10 criteria (World Health Organization 1992) for dependence syndrome (Reference Edwards and SalibEdwards 2002). There has been epidemic increase in the use of cocaine and opiates by US trauma care patients (Reference Soderstrom, Dischinger and KernsSoderstrom 2001). In an American study, Reference Aurora, Gunnerson and UrrunagaAurora et al (2000) report the prevalence of cocaine in an inner-city elderly population to be six times higher than estimated by the National Household Survey of Drug Abuse (www.oas.samhsa.gov/cocaine.htm) in 1997. An American study among older adults (over 60 years) attending an emergency department found that 2% tested positive for cocaine. Rates of older adults entering treatment for cocaine use are estimated at 0.1% among those aged over 65 (Reference Rivers, Shirazi and AuroraRivers 2004). Although opiate pain relief is an essential part of palliative treatment for chronic illnesses, this has led to varying degrees of misuse, ranging from inappropriate use to dependency. This implies that palliative prescribers should balance between the benefits and the possible harm from misuse of opiate-based prescribing.

There have been sporadic observations of the use of illicit substances by older persons susceptible to influence by younger loved ones who use drugs. According to Reference Atkinson, Jacoby and OppenheimerAtkinson (2002) opioid misusers are often men who have survived their addiction for years, led socially isolated lives and have been secretive about drug use. They have tended to avoid law enforcement agencies, often continue to support their drug habits through legal employment and tend to enter methadone maintenance as they become too old to obtain drugs illicitly.

Emerging evidence is that alcohol dependence and a history of childhood abuse are associated with misuse of illicit or prescribed opioids among older adults (Reference MenningerMenninger 2002). Increasing numbers of older people are presenting with drug problems (data available from the authors on request) and are on methadone maintenance treatment (Reference Badrakalimuthu, Tarbuck and WagleBadrakalimuthu 2010).

A study that looked at older adults visiting emergency departments found that use of cocaine among older adults was associated with relatively young age (66 years), male gender and a diagnosis of alcohol or drug misuse (Reference Rivers, Shirazi and AuroraRivers 2004).

Other drugs

Reference Blazer and WuBlazer & Wu (2009) studied more than 10 000 people over the age of 50 and reported that 2.6% had used cannabis and 0.41% had used cocaine in the past year. However, the misuse (‘abuse or dependence’) rates were much lower, at 0.12% for cannabis, 0.18% for cocaine and 0.33% for any drug.

For drugs such as stimulants and hallucinogens there are no reliable data available. However, in a study of more than 50 000 people aged over 55, 12.6% reported that opioids (legal and illegal) were their primary substance of misuse and 1.3% reported prescribed sedatives, tranquillisers and stimulants as their primary substance of misuse (Drug and Alcohol Services Information System 2004). A projective study by Reference Gfroerer, Penne and PembertonGfroerer et al (2003) estimated that among 244 000 older adults abusing drugs, the most common drugs of misuse were cannabis (42%), cocaine (36%), pain relievers (25%), stimulants (18%) and sedatives (17%).

Chronic and painful diseases are associated with the use of cannabis in elderly people. Pain increases the drive to use any drug that produces euphoria and some studies have reported severe misuse of cannabis (Reference Trafton, Olivia and HorstTrafton 2004). Women are at the highest risk of misuse of prescription drugs (Reference Patterson and JestePatterson 1999), whereas men are more likely to misuse stimulants, sedatives and tranquillisers. Previous or current misuse of illicit substances is associated with misuse of prescription drugs (Reference Simoni-Wastila and StricklerSimoni-Wastila 2004).

Inappropriate and over-the-counter medications

The Drugs Services Research Survey in the USA (Reference Batten, Prottas and HorganBatten 1992) reported that 10.1% of a representative sample of individuals discharged from drug user treatment admitted to non-medical use of more than one prescription drug in the 30 days before admission; 17.7% said that prescription drugs were their drugs of choice. One in ten older people is receiving a prescribed drug that is potentially inappropriate (Reference GottliebGottlieb 2004). Problems are recognised to occur both with over-the-counter remedies, such as laxatives, analgesics and antihistamines, and with prescribed drugs, including diuretics, benzodiazepines and antidepressants.

On average, elderly people are prescribed twice as many medications as working-age adults. Prescribing is often less rational, with less stringent monitoring, particularly in institutional settings, and there is increased complexity of medications, hoarding and drug-sharing (Reference McGrath, Crome and CromeMcGrath 2005).

Psychotropic drug misuse is four times greater among women than men and the risk of dependence is increased if the women are widowed, less educated, of lower income, in poor health and with reduced social support (Reference King, van Hasselt and SegalKing 1994). Reference Simoni-Wastila and YangSimoni-Wastila & Yang (2006) reported that 11% of older women misuse prescription drugs. An association may exist between age-related physical morbidity (such as arthritis) and misuse of medications which may partly be due to difficulties that older individuals have in reading and following instructions. Risk factors in elderly people include personality disorders, somatoform disorders, anxiety, sleep disturbance and adjustment disorders (Reference Mossley and ShapiroMossley 1985).

Polysubstance misuse

Past studies showed that multiple illicit drug use in elderly people has been largely limited to ageing criminals and long-standing opioid addicts (Reference Finlayson, Hurt and DavisFinlayson 1988). Polysubstance misuse usually takes the form of coexisting dependence of alcohol and either prescribed sedatives or opioid analgesics (Reference Finlayson and DavisFinlayson 1994). However, prevalence data from UK regional drugs databases indicate that patterns of drug use are changing, with more similarities to younger drug-using populations (data available from the authors on request).

A study conducted in Pennsylvania reported that 77% of prescription drug users were on drugs that interacted with alcohol and 19% reported concomitant alcohol use. Sixteen per cent of opioid analgesic and benzodiazepine users reported concomitant alcohol use (Reference Pringle, Ahern and HellerPringle 2005). Of all emergency department visits involving opioid analgesics, 72% were associated with multiple drug misuse (Reference Gfroerer, Penne and PembertonGfroerer 2003).

Difficulties in diagnosing drug dependence

Retirement, isolation and lack of corroborative information can reduce the possibility of diagnosing drug misuse in elderly people. An audit conducted in Norfolk in 2005 revealed that 60% of elderly people admitted to an acute psychiatric ward had no documented notes on drug or alcohol history (data available from the authors on request). The same study reported that junior doctors felt that it was inappropriate to ask patients about their drug or alcohol history, believing that it would be a negative finding or might cause offence, and reported that they had not received appropriate training for assessment and treatment of drug misuse in elderly people.

In a study by Reference McInnes and PowellMcInnes & Powell (1994), the medical staff on general hospital wards identified only 3 out of 88 problem users of benzodiazepines and of those identified, only 2 benzodiazepine users were considered for referral to drug and alcohol services.

Substance dependence or misuse may be mistaken for depression and dementia. Delirium, a common presentation of withdrawal in elderly patients, may be misattributed to other causes (Reference Foy, O'Connell and HenryFoy 1995). Reference Whitcup and MillerWhitcup & Miller (1987) report benzodiazepine dependence and withdrawal being initially overlooked in elderly patients who do not, or cannot, disclose their daily use of these agents. The ensuing course of illness was often misdiagnosed as myocardial infarction, hypertensive crisis or delirium. The ICD–10 criteria (World Health Organization 1992), with classic features such as craving, may be absent and the older patient may be in denial with not much information being available upon direct questioning. Ageism, lack of awareness, complexity of presentations with overlapping symptoms between substance dependence, physical illness and psychiatric disorders can obscure substance misuse. Relatives eager to safeguard the reputation of the family may try to deny the existence of any problem. Substance use and misuse among ethnic subgroups remains a much-understudied area.

Improving diagnosis

There are many ways to improve the chances of diagnosing substance misuse in elderly people (Box 3). Good history-taking skills, the use of motivational interviewing technique, a good knowledge of diagnostic criteria and physical and psychiatric sequelae of drug misuse, and liaison with other medical colleagues involved in managing the elderly patient would also increase the chances of accurate diagnosis.

Substance misuse and mental health

Reference Frischer, Crome and MacleodFrischer et al (2005) found a 27% increase compared with the general population in comorbid psychiatric illness and substance misuse in elderly patients attending primary care; benzodiazepines with a consequence of confusion were the most common drugs involved. Reference Blixen, McDougall and SuenBlixen et al (1997) reported that 37.6% of elderly psychiatric hospital patients had a substance use disorder in addition to a psychiatric disorder. Of this dual diagnosis group, 29% misused both alcohol and other substances, made significantly more suicide attempts (17.6%) and 5% of the over-60 population had overdosed on drugs that they had misused.

Eighty per cent of people with a psychoactive drug disorder also had a disorder involving alcohol or a psychiatric comorbidity. Among older adults admitted to hospital with prescribed drug dependence, 32% had mood disorder, 28% had organic mental disorder, 27% had personality disorder, 16% had somatoform disorder and 12% had anxiety (Reference Finlayson and DavisFinlayson 1994).

Substance misuse and physical health

Older adults with substance misuse disorders make greater use of healthcare resources than those without. They also tend to utilise emergency departments frequently (Reference Simoni-Wastila and YangSimoni-Wastila 2006).

Physiological changes in elderly people, such as altered lean body mass or reduced kidney function, can dramatically alter the serum level of drugs, especially in people with comorbid chronic physical illness or an acute infection. Natural progression of physical illness such as liver disease caused by hepatitis C might mean that the effects of drug use are evident only in old age.

There is a significant relationship between psychotropic drugs and falls (Reference Lord, McLean and StathersLord 1992). Evidence shows that elevated liver enzymes, hepatitis, pancreatitis, hypertension, arrhythmia and lung disease may also be indicative of substance misuse in elderly people (Reference MenningerMenninger 2002). Reference Rosen, Smith and ReynoldsRosen et al (2008) reported a high rate of physical health problems: arthritis (54.3%) and hypertension (44.9%) being more common, with more than half reporting a subjective sense of poor health.

Apart from symptoms of tolerance and physical dependency, opioid misuse is associated with increased risk of sedation, impaired motor coordination with codeine and propoxyphene and substantial impairment of vision, inattention and impaired motor coordination with oxycodone and meperidine (Reference Ray, Thapa and ShorrRay 1993).

Reference Lofwall, Brooner and BigelowLofwall et al (2005) reported that, compared with a younger cohort, the older group who began using illicit substances in late life had significantly more medical problems and worse general health than the younger group.

The impairment produced by benzodiazepines can represent a more severe compromise than the same dose given to younger people (Reference Woods and WingerWoods 1995). Benzodiazepines may contribute to respiratory insufficiency in patients with pulmonary disorders and potentiate the effects of alcohol and opioids. Benzodiazepine use in elderly people is associated with falls (Reference Neutal, Hirdes and MaxwellNeutal 1996), road-traffic accidents (Reference NeutalNeutal 1995), hip fracture (Reference Wagner, Zhang and SoumeraiWagner 2004) and cognitive impairment (Reference Foy, O'Connell and HenryFoy 1997). Benzodiazepine withdrawal delirium occurred most frequently in older patients with an increase of neuropsychiatric complications (Reference Wetterling, Backhaus and JunghannsWetterling 2002). Serious and distressing discontinuation symptoms occur in as many as 90% of patients who have been taking low daily doses. Grand mal seizures occur in 20–30% of people dependent on benzodiazepine whose withdrawal is untreated.

Drug use and cognition

Cognitive impairment from drug use might be overlooked, misdiagnosed and mistreated in elderly patients. Physical illness that impairs sensory and motor systems, prescribed medication use and functional psychiatric illnesses can affect the cognitive assessment. Cognitive function is also influenced by variations in the quantity and duration of substance use and the phase of intoxication or withdrawal.

Impairments have been reported in long-term memory, psychomotor speed, and learning and retention of new information in elderly people taking diazepam (Reference Hinrichs and GhoneimHinrichs 1987), and in verbal memory, visuospatial ability and psychomotor activity after withdrawal from long-term use of benzodiazepines (Reference Barker, Greenwood and JacksonBarker 2005). Interestingly, Reference Habraken, Soenen and BlondeelHabraken et al (1997), hypothesising that benzodiazepine-related cognitive impairment may increase with age, observed a significant improvement in cognition in patients with dementia when these drugs were withdrawn. Unfortunately, specific consequences of misusing substances other than benzodiazepines have not been reliably studied.

Cognitive impairment, such as problems with verbal abstraction, may cause inability to take advantage of treatments that require higher-order cognitive processing, such as learning new problem-solving strategies.

Benzodiazepines and hypnotics

It can be very difficult to persuade elderly people to give up sedatives, but gradual discontinuation is often is indicated. Psychosocial factors maintaining their use should be managed. If prescription of sedatives is necessary, the physician should try to ensure that the patient understands the likelihood of physical dependence and potential withdrawal symptoms after prolonged use. The standard guidelines for tapering and discontinuing benzodiazepines and hypnotics in working-age adults may need to be tailored to the needs of elderly patients.

Opioids

Elderly methadone-dependent patients are more likely to be seen in geriatric settings (Reference Miller, Belkin and GoldMiller 1991; Reference Gurnack, Atkinson and OsgoodGurnack 2002), are less likely to request detoxification and tend to continue the dose of methadone that they received when they were younger (Reference Hiltunen, Lafolie and MartelHiltunen 1995; Reference Gurnack, Atkinson and OsgoodGurnack 2002). Reference Gurnack, Atkinson and OsgoodGurnack et al (2002) also reported that older patients on methadone maintenance tend to prefer higher doses. They also face a variety of physical and psychosocial obstacles in accessing maintenance treatment programmes. Treatment for older adults with opioid dependence should include expert medical advice because of frequent comorbid medical conditions and the metabolic changes associated with ageing.

Despite such difficulties, patients who had a long history of opioid misuse tended to stay in treatment programmes (Reference Firoz and CarlsonFiroz 2004). Reference Saxon, Wells and FlemingSaxon et al (1996) reported that old age predicted retention in methadone maintenance treatment at the end of 18 months. Their psychosocial profiles and the benefits of maintenance treatment are similar to those in younger patients.

The other main group of older opioid-dependent patients are those with severe dependence on analgesic medication. Prescribed medication may be supplemented with over-the-counter or illicitly obtained drugs or drugs prescribed for a relative or friend. High-dose medication in those referred for specialist treatment is more usual. Assessment of underlying pain is essential, ideally in collaboration with a pain specialist, and cognitive approaches to pain management can be helpful. The likelihood of underlying depression requires consideration and if depression is identified it should be treated before opiate reduction or withdrawal. A change to longer-acting opioids allows easier reduction. Expert advice should be sought regarding the practicalities of treatment.

Over-the-counter and inappropriate medications

Apart from physicians, pharmacists are in a unique position regarding surveillance of repeat prescriptions and supervision of over-the-counter sales to the public to help in monitoring the use of such medications. Reference McGrath, Crome and CromeMcGrath et al (2005) recommend that community pharmacists, in conjunction with general practitioners and physicians, have a responsibility towards reducing misuse among older people. The role of the community pharmacist should include a thorough assessment of the patient's problems before supplying medicines.

The important treatment issues for general practitioners, geriatricians and psychiatrists are to be aware of the possibility of addiction, to review medications regularly and to investigate and manage psychosocial factors that might be triggering misuse.

Associated alcohol misuse

Primary and specialty care providers can be trained to provide motivational, brief alcohol interventions targeted at older patients in a range of healthcare settings. Guided self-management and in-depth relapse prevention work would be useful in obtaining a better prognosis. Emphasis should also be placed on non-drinking social activities in the context of the person's circumstances and social support networks. It is reasonable to assume that such techniques could be successfully applied to drug problems.

In general, the management of associated alcohol misuse is the priority before addressing other substance dependencies because of the effects of alcohol on cognition and mood and the risks to physical health.