Risk Factors for Drug Abuse

Addiction is a primary, chronic, neurobiological condition, influenced by genetic, psychosocial and environmental factors. Men are twice as likely as women to experience drug problems. Factors that may contribute to drug use include:

Persons Who Use Drugs (PWUD)

Substance abuse is increasingly common in many parts of the world. The pattern of drug use in the British Crime Survey by 2012 is shown in Box 34.2.

The 2012/13 Crime Survey for England and Wales showed that in the past year:

In the USA, the highest rates of illicit drug use are: in males – in entertainment, food preparation and service, cleaning services and construction; and in females – in food preparation and service, social work and legal professions, including lawyers and legal assistants. Abuse of alcohol is highest among construction workers, car mechanics, food preparation workers, light truck drivers and labourers. Unmarried workers or those having three or more jobs in the previous 5 years report about twice the rate of illicit drug and heavy alcohol use as married workers or those who had two or fewer jobs.

The lowest rates of illicit drug use are in workers in occupations that require public trust, such as health-care professions (HCPs), police officers, teachers and child-care workers. Between 10 and 15% of HCPs misuse drugs or alcohol at some time during their life – rates similar to those seen in the general population. Alcohol abuse is relatively common among doctors and dentists, and one study of USA medical personnel found that over half had tried marijuana or cocaine recreationally, or opioids or tranquillizers for self-treatment. HCPs have higher rates of abuse with benzodiazepines and opiates, and abuse drugs for performance enhancement and as self-treatment for various reasons, such as pain, anxiety or depression. Those in anaesthesia, emergency medicine and psychiatry have the highest rates of drug abuse.

Drugs and alcohol used by medical and dental students are mostly for ‘recreational’ purposes. More than a half of UK dental students in 2003 had used cannabis and over one-third admitted other illicit drug use. Some 6–10% of dentists may abuse drugs, but there is limited evidence to suggest that they are at a greater risk for abusing alcohol or other drugs than the public. Alcohol and tobacco are the substances abused most frequently by dentists, followed by opiates (mainly hydrocodone and oxycodone) and nitrous oxide. Other substances abused include marijuana; opiates (e.g. morphine, fentanyl, pethidine (meperidine), hydromorphone and oxycodone); minor opiates (e.g. hydrocodone and codeine); and anxiolytics (e.g. alprazolam and diazepam). Interpersonal and life circumstances that contribute to dentists misusing drugs and alcohol include career choice dissatisfaction, domestic breakdown, low professional or self-esteem, obsessive–compulsive and perfectionist behaviour, interpersonal relationship difficulties, and stress at work.

Dentists who become aware and are sure of a colleague’s chemical dependency have professional and ethical responsibilities to intervene in a constructive manner. All dentists have an ethical obligation to urge chemically impaired colleagues to seek treatment. Interventions involve discussing the issue with the addicted dentist, offering help if possible, and reporting the dentist to a wellness committee. Once a person with an addiction accepts the presence of the issue and expresses a desire to change, treatment can begin, but it should be individually designed by professionals experienced in treating drug and alcohol abuse. Clinicians in the UK who have such issues can receive support from the Practitioner Health Programme, initiated by the National Clinical Assessment Service (NCAS; http://www.php.nhs.uk/, accessed 30 September 2013).

Recognizing and Detecting Substance Abuse

Behavioural traits that should increase the level of concern include loss of reliability, mood changes, impaired driving, and the self-prescribing of mood-altering medications. Care should be taken with any patient who has subjective symptoms with no objective evidence of the disorder; makes a self-diagnosis and requests a specific drug, especially a psychoactive agent; appears to have a dramatic but unexpected complaint, such as trigeminal neuralgia, requiring potent analgesics; firmly rejects treatments that exclude psychoactive drugs; and has no interest in the diagnosis or investigations, or refuses a second opinion.

To help a friend/colleague address such problems, it is important to document the dates and times when people have expressed concern and when the signs of substance abuse were noted. These may include the smell of alcohol, tremor, slurred speech, ataxic gait and sloppy appearance. It is important to monitor and document incidents so that this information will be available when discussing concerns with a friend or colleague. The user’s first response is typically denial – and a person in denial will often try to convince others that their assessments are wrong or misguided. Recognition of abuse in an HCP may include, in addition to the above, patient and staff complaints about deteriorating attitude and behaviour, worsening personal and professional isolation, excessive amounts of time spent near a drug supply, heavy ‘wastage’ of drugs, sloppy record-keeping, suspect ledger entries and drug shortages, inappropriate prescriptions, or insistence on the personal administration of injected narcotics to patients.

Medical and Social Complications of Drug Abuse

There may be intense drug dependence (or psychological addiction; Table 34.2) and physical effects (physical addiction) in people who use drugs (PWUD) or if a drug of abuse is stopped (withdrawal syndrome) (Fig. 34.1).

Use of illicit drugs is associated with increased rates of infections (e.g. tuberculosis and sexually shared infections [SSIs]), and health and social issues related to alcohol, tobacco and other drugs. Injection drug use is an important route of transmission of blood-borne infections, particularly HIV and viral hepatitis B and C.

Drugs bought on the street are especially hazardous, as they are not necessarily pure and are frequently adulterated or falsely labelled, often with unknown ingredients that may be dangerous in their own right. For example, PWUD who think they are purchasing a drug such as MDMA (ecstasy; 3,4-methylenedioxy-N-methylamphetamine) may be in danger of receiving synthetic cathinones instead; mephedrone has been found as a substitute for MDMA in pills sold as ecstasy in some countries. Intravenous use and the mixing of drugs (polydrug use) are particularly hazardous; those who misuse drugs not uncommonly misuse several substances, including alcohol and tobacco, and may well neglect their health – general and oral. Heroin and cocaine are especially dangerous. Tobacco and alcohol also cause significant harm, but cannabis appears to be less harmful in general.

Almost every month, new synthetic drugs, opiate painkillers and other substances emerge as popular among partygoers and drug addicts. Recently appearing new drugs include:

See also “LEGAL HIGHS” and “EMERGING DRUGS”.

Clinical Features

Signs and symptoms that may indicate drug addiction include behavioural and social features, as well as health aspects (Table 34.3). There can be serious medical and behavioural consequences affecting both user (and any fetus) and others in the community, not least because of assaults, theft and prostitution used to fund the drug habit. Maxillofacial injuries and sexually shared and other infectious diseases are thus common consequences. Intravenous injection is common in drug misuse, often with filthy injection technique, sharing of needles or syringes (with the risk of blood-borne infections) and even use of water from a lavatory pan to dissolve the drug. Viral hepatitis (particularly B, C, D and others), chronic liver disease, human immunodeficiency virus (HIV) and other blood-borne agents are common consequences of intravenous drug abuse or drug ‘snorting’. Infective endocarditis and consequent cardiac lesions may stem from infected injections. Venous thromboses are common, making intravenous injection difficult.

General Management

Common management difficulties are behavioural problems, including irregular health care, poor attendance and compliance, effects of trauma and the frequent risk of maxillofacial and other injuries during assaults or fights, and hazards of cross-infection with hepatitis viruses, HIV and, increasingly, tuberculosis. PWUDs who collapse or become hyperthermic, drowsy or panicky may well need emergency care (Table 34.4). Many drugs of abuse can alter behaviour or interact with drugs used for medical or dental purposes (Ch. 29). There can therefore be substantial difficulties in interactions between HCPs and drug users. However, it is unethical to withhold treatment from any patient on the basis of a moral judgment that the patient’s activities or lifestyle might have contributed to the condition for which treatment was being sought.

Main Groups of Drugs Abused

Patterns of drug misuse change rapidly, depending on fashion and cultural factors, availability and cost. New agents are constantly appearing, often in an attempt to circumnavigate the law and frequently under a variety of names, and may have adverse effects. For example, benzylpiperazine (BZP; A2, legal E, legal XTC, legal high, Jax, London Underground, Pep twisted or Pep love) appeared as an alternative to ecstasy but caused serious adverse effects (see http://www.justice.gov/dea/druginfo/factsheets.shtml and http://www.talktofrank.com/home_html.aspx; accessed 30 September 2013).

The main groups of drugs abused are stimulants (uppers), depressants (hypnotics/sedatives/downers), hallucinogens (psychedelics) and anabolic steroids (Table 34.5). Alcohol, tobacco, solvents, cannabis and ecstasy have been popular for many years; apart from these, heroin is the main drug of misuse, followed closely by mephedrone, methadone and cocaine (Tables 34.5 and 34.6). Other drugs commonly abused include amphetamines, barbiturates, benzodiazepines, methaqualone and opium alkaloids. Drugs abused may be obtained legally from a doctor or chemist, or may be illicitly obtained. They may be taken orally, inhaled, or injected into the skin, muscle or a vein.

Prescription drugs are commonly abused – notably stimulants, CNS depressants, analgesics and opioids.

Club drugs are those used by teenagers and young adults who are part of a nightclub, bar, trance or rave scene – night-long dances, often held in warehouses (Table 34.7). In high doses, club drugs can cause a sharp rise in body temperature (malignant hyperthermia) leading to muscle breakdown and renal and cardiovascular system failure.

Date-rape drugs, such as gamma-hydroxybutyric acid (GHB), Rohypnol (flunitrazepam) and ketamine, are used because they lack colour, taste and odour, and thus can be added to beverages to be ingested unknowingly by the victim. They are CNS depressants that cause loss of inhibitions and memory. They can also readily cause unconsciousness.

Stimulants

Stimulants are substances that cause excitement and euphoria (a ‘high’), which may last several hours. Withdrawal symptoms (restlessness, agitation, sleeplessness and depression) may follow. Heavy use of strong stimulants for weeks may cause paranoia and auditory hallucinations – effects that may be irreversible (Table 34.8).

Stimulants cause moderate to severe psychological addiction. Withdrawal is purely psychological and psychosomatic. They include:

Stimulants used in various cultures include betel, caffeine, cocaine, kava, khat, kratom, marijuana, salvia and tobacco (Table 34.9). Common herbal sources of psychedelics include Psilocybe mushrooms (‘magic mushrooms’), seeds of morning glory (from the Convolvulus family), peyote (from a cactus in the south-west USA), various ayahuasca preparations (from the Banisteriopsis species of vine from Amazonia), San Pedro cactus (from a cactus found in Peru, Bolivia, Chile and Ecuador) and Hawaiian baby woodrose (a vine from India, the Caribbean, Hawaii and Africa).

Inhalants are stimulants that are volatile chemical vapours that produce psychoactive effects. Many are available over the counter, including solvents (paint thinners, gasoline, glues), gases (butane, propane, aerosol propellants, nitrous oxide), nitrites (isoamyl, isobutyl, cyclohexyl – used to enhance sexual arousal) and sprays (e.g. deodorants; Table 34.10). ‘Laughing gas’, ‘poppers’, ‘snappers’ and ‘whippets’ are commonly used terms. Sniffing inhalants produces psychotomimetic effects somewhere between those of alcohol and general anaesthesia (GA), in that initially users may feel slightly stimulated; with successive inhalations, they may feel less inhibited and less in control. Users may appear drunk and giggling with slurred speech and unsteadiness. Adverse effects include headache, nausea or vomiting, wheezing, unconsciousness, cramps, weight loss, muscle weakness, depression, memory impairment, damage to cardiovascular and nervous systems, and unconsciousness. Inhalant misuse is increasingly common in children and young adults, and has led to many deaths. Sniffing highly concentrated chemicals such as fluorocarbons and butane-type gases can damage liver and CNS, or cause delusions, hypoxia, arrhythmias and sometimes sudden death. Deliberately inhaling from an attached paper or plastic bag, or in a closed area, greatly increases the chances of suffocation. Users can also choke on their own vomit. Chronic solvent misuse can impair memory and concentration, and permanent damage to the brain, liver or kidneys has been reported. Respiratory damage, anaemia, lead poisoning and cranial nerve palsies can follow chronic misuse of petrol. A syndrome of learning disability, hypotonia, scaphocephaly and high malar bones has also been reported in children of mothers who inhaled petrol during pregnancy (fetal gasoline syndrome). Specific chemicals may also have additional adverse effects (Table 34.11). Signs of solvent misuse include slurred speech, euphoria, anorexia and a circumoral (glue sniffers’) rash. Jaundice may be seen and the pulse may be irregular.

Depressants

Depressants (including alcohol) depress the CNS, causing drowsiness; poor concentration, judgment and memory; disorientation; ataxia; and, in severe cases, unconsciousness (Table 34.12). Sedatives and hypnotics may cause mild to severe psychological addiction, and severe physiological addiction; abrupt withdrawal may be fatal. They include:

Hallucinogens

Hallucinogenic drugs cause sensory distortions, including mood changes, feelings of disassociation, auditory and visual disturbances, and changes to taste or smell. Hallucinations are quite dangerous, as sufferers may present extreme danger either to themselves or to others (Table 34.13).

Anabolic Steroids

See Chapter 33.