Cocaine Use: Recommendations in Treatment and Rehabilitation

4. Effects of Cocaine

Cocaine is a powerful stimulant that produces behavioural changes, and affects the neurological, cardiovascular, gastrointestinal and respiratory systems of the body. Cocaine provides two strong pharmacological actions. It is best-known for acting as a stimulant to the central nervous system. Less well-known are its properties as a local aneasthetic. At the level of the central nervous system, cocaine works by blocking the re-uptake of neurotransmitters (dopamine, norepinephrine and serotonin) at the synaptic junctions. This has a strong impact on the pleasure centre of the brain (the limbic system), producing a strong euphoric effect that can result in increased alertness, activity and talkativeness, and a decrease in appetite. As well, a greater sense of well-being may lower anxiety and inhibitions (Volkow et al., 1997; Das, 1993; Fleming et al., 1990; Hall et al., 1990; Warner, 1993).

Many cocaine users are multi drug users (poly drug users), making it difficult to specify cocaine's physical and psychological complications, and to disentangle its effects from those of alcohol, marihuana, other illicit drugs, and the user's lifestyle. Estimation of drug dosages is limited by a lack of reliable reporting, and the fact that cocaine sold on the street may be adulterated with a variety of types and amounts of other substances. Still, this area of cocaine research is growing, and it draws on studies conducted in hospitals and treatment centres, as well as some recent longitudinal studies, which allow a more careful tracking of cocaine's effects over time (Chen et al., 1996; Gorelick, 1992; Warner, 1993).

4.1 Routes of Administration

Cocaine can be "snorted" through the nose, smoked or injected. The duration of the immediate euphoric effects of cocaine depend on the route of administration; smoking or injecting cocaine gives a more immediate high than snorting. However, the faster an effect is achieved, the shorter the duration of the effect; the high from smoking may last 5-10 minutes, while that from snorting may last 15-30 minutes (NIDA, 1998).

4.2 Effects of Short-term Use

At low doses (single doses up to approximately 20 mg), cocaine produces a range of behavioural, neurological, cardiovascular, respiratory and gastrointestinal effects (Brands, Sproule and Marshman, 1998). These include feelings of euphoria, contemplation, anxiety or panic, increased energy, talkativeness, mental alertness, and postponement of the need for sleep and food. Some people report that the drug helps them to perform simple physical and intellectual tasks more quickly. Physical symptoms include increased heart rate, blood pressure and rate of breathing, and a dry mouth.

At higher doses, (several hundred milligrams, or less for more sensitive individuals), the symptoms experienced at lower doses are exaggerated, resulting in intense euphoria followed by agitation, anxiety, flight of ideas, grandiosity or erratic or violent behaviour, and, in some cases, paranoid psychosis. Physical symptoms may include nausea and vomiting, blurred vision, muscle twitches and tremors, elevated blood pressure, fluid in the lungs, chest pain, and other lung damage. The possibility of serious harm or death also increases, and higher dosages have been linked with seizures, strokes and cerebral infarction, heart attack or depression of respiration (Brands, Sproule and Marshman, 1998).

A recent study funded by the National Institute on Drug Abuse (NIDA) found that women were less sensitive to the effects of cocaine than men. The authors of the study (Lukas et al., in press) believe that these gender differences are attributable to differences in the speed at which cocaine is metabolized, and also to barriers created to absorption of cocaine by the presence of more mucous in women's mucous membranes during certain phases of their menstrual cycle. The authors speculate that although women may be less sensitive to the effects, they may need to take more cocaine to experience the same effect as men (NIDA Notes, January/February, 1996).

4.3 Effects of Long-term Use

Long-term chronic cocaine use may result in damage to the tissues of the nose and perforation of the nasal septum among those who snort, lung damage among those who smoke, and increased risk of overdosing, infections and sexually transmitted disease among those who inject. In addition, the chronic user who alternates between "cocaine binges" and crashes is likely to experience dramatic mood swings from agitation and excitability to severe depression, panic attacks, paranoid thinking, violent behaviour, suicidal ideation, cognitive impairment, sleep disorders, eating disorders, sexual dysfunction, kidney problems, and at times visual and auditory hallucinations (Brands, Sproule and Marshman, 1998; Blank-Reid, 1996; Hall et al., 1990; Das, 1993; Di Paola et al., 1997; Gourgoutis and Das, 1994; Mittenberg and Motta, 1993; Rosselli and Ardilla, 1996).

4.4 Onset of Long-term Effects

Complications from cocaine use may take time to manifest themselves. Chen et al. (1996) conducted a longitudinal study of a U.S. high school cohort of 1222, and followed them over a 20-year period after their 1971 graduation from high school. They found that medical complications often did not arise in cocaine users until they were in their thirties. Over time, however, ongoing cocaine use led to more cardiovascular, neurological and general health problems, as well as negative self-reported health and sick days. Chronic users reported more health problems than less frequent cocaine users. In this study, the authors controlled for socio-demographic characteristics, pre-existing health problems, and the effects of tobacco, alcohol and marihuana. The authors concluded that health problems may not be apparent in individuals who use cocaine during their twenties but, by their thirties, a cumulative effect will become evident, and more health problems will ensue.

4.5 Tolerance and Dependence

Individuals who use cocaine may develop tolerance to the euphoric effects of cocaine, leading some to raise their dose to increase or prolong the effects; some chronic users develop an increased sensitivity to cocaine's adverse effects (Brands, Sproule and Marshman, 1998). On cessation of use regular users experience withdrawal symptoms that are common to withdrawal from other central nervous system stimulants, such as depression, exhaustion, extended sleep and hunger. Regular users also develop a strong psychological dependence on the drug with intense cravings when the drug is not available. Brands, Sproule and Marshman (1998) indicate that the abuse liability of cocaine is the highest of all illicit drugs because of the powerful euphoria and the rapidity with which it is achieved, particularly when the drug is injected or smoked.

Withdrawal from cocaine is believed to fall into three phases. The "crash" period lasts from 9 hours to 4 days. It initially produces agitation, depression, anorexia and high cocaine craving, and later it is associated with fatigue, depression, insomnia, no craving, and finally exhaustion. The middle phase, "withdrawal," lasts from 1 to 10 weeks and swings from initial low anxiety and craving to high anxiety and cravings in the latter stages. The third and final phase, "extinction," is an indefinite period and features a normal mood but episodic craving, which can be triggered by conditioned cues learned during past cocaine use (Halikas et al., 1993; Hall et al., 1990). However, not all researchers agree on the presence of craving. Flowers and her colleagues (1993) recorded the daily cravings of 15 cocaine-abusing patients who were just admitted to a residential treatment program. Patients reported almost no cravings, generally positive moods, and strong (but not too strong) energy levels. These researchers concluded that cocaine-withdrawal effects were more psychological than physiological. In a somewhat similar fashion, Miller and Gold (1994) found that cocaine-dependent patients reported impulsivity, not craving, as the reason for relapse. They argue that chemical changes in the brain may be present, but a physical craving related to these changes is too small for patients to detect. They suggest that cocaine abuse may be part of a learned behaviour or lifestyle that creates psychological (rather than physical) motivation.

4.6 Lethality

Toxicity of cocaine is a concern raised in cases of cocaine-related "sudden" deaths and instances of heart attack, seizure and stroke (Benowitz, 1992; Biebuyck, 1990; Smart, 1991). A safe maximum dosage of cocaine is considered to be about 200-300 mg. The relation of toxicity to frequency of use or dosage size remains an open question. Sudden deaths attributable to toxicity sometimes involve cases where only small amounts of cocaine (30 mg.) have been consumed (Benowitz, 1992; Biebuyck, 1990; Middleton and Kirkpatrick, 1993). Measurement of dosage in toxic cases is problematic because of individual variation in rate of absorption, metabolism, frequency of use, and type of administration (e.g. intranasal vs. injection). The timing of blood tests in the case of fatalities will also affect estimates (i.e., when the body was discovered, the time it took for medical personnel to arrive, when the sample was taken). Metabolism continues post-mortem, which also complicates interpretation of cocaine levels (Middleton and Kirkpartrick, 1993). Benowitz (1992) suggests that the profile of overdose deaths has changed. He observes that, in the United States in the 1970's, cocaine was a drug used by a young middle-class group, while now frequent users are from inner city or lower socioeconomic groups who are prone to poor health and more likely to be poly drug users. Cases of cocaine toxicity were rare in the 1970s, but overdose deaths from cocaine are now a major concern, particularly in larger urban centres.

Cocaine-related deaths may also result from using other substances with cocaine. U.S. researchers have found that the human liver combines cocaine and alcohol, and manufactures a third substance called cocethylene, which intensifies cocaine's euphoric effects but may also increase the risk of sudden death (NIDA, 1998). Combining cocaine with other analgesics such as heroin also increases the risk of sudden death.

4.7 Reasons for Using and Quitting, and Perceptions of Effects

The reason for using cocaine may affect self-reported health outcomes, depending on whether cocaine is being used for social or coping reasons. White and Bates (1993) assessed survey results from 1270 young adults and found that respondents who identified coping reasons tended to be heavier users, and to report more negative outcomes.

Self-attributed negative outcomes ranged from psychological (became terrified for no reason), dependent (missed out on things, went to school or work high) physical (passed out), or legal and interpersonal (relatives avoided me, been in trouble with police).

Although cocaine can produce a powerful psychological dependence, research also suggests that cocaine users are not oblivious to the health problems related to use. Some users recognize health problems and take action. In a Canadian study, Cheung et al. (1991) found that concern over heart problems, nausea and other negative health aspects of cocaine led to users quitting. In a U.S. study (Waldorf and Murphy, 1995), the authors found that middle-class cocaine dealers often quit because their own use led to health problems.

4.8 Concurrent Cocaine Use and Psychiatric Disorders

Many people with cocaine problems also have serious Axis I mental disorders (Hoffman, et al., 1996) and Axis II personality disorders and psychological disorders (Marlowe, et al., 1997). The latter group is particularly problematic, as they have been shown to do poorly in treatment programs for all types of disorders. In an extensive evaluation of the impact of personality disorders among individuals who use cocaine, Barber et al. (1996) found that 47% of their sample met criteria for one or more personality disorders. Those with personality disorders, (compared to those without this condition), had more additional psychiatric disorders, and were more likely to be involved in criminal activities. The most common Axis II diagnoses were antisocial (20%) and borderline (11%).

In another study, Anthony and Petronis (1993) compared the rates of psychiatric disturbances among individuals who use cocaine to a matched set of young adult non-users and found that, in comparison to the non-users, the individuals who used cocaine were 3.7 times more likely to report panic attacks, 3.2 times more likely to report panic disorders, twice as likely to report that they were depressed, and 11.8 times more likely to report a manic episode. The study was unable to directly link these disturbances with the amount of use or withdrawal, nor did it carefully assess individual predisposition, lifestyle or poly drug-use questions. The study clearly, however, shows a greater probability of psychiatric disturbances for individuals who use cocaine. Given the sample size and the time period covered, it represents one of the stronger research efforts attempting to quantify differences in psychiatric disturbances between cocaine users and non-users.

It is not always clear, however, to what extent psychiatric disorders are associated with or independent of the use of cocaine. A study of 50 patients hospitalized for cocaine dependence by Weiss and his colleagues (1993) found that the majority of these patients were rated antisocial according to DSM-III-R, and that these diagnoses were present both during drug use and in periods of abstinence. These findings suggest that personality disorders are conditions that exist independently of cocaine use.

Although psychiatric symptoms may be attributable to cocaine use or cessation, the persistence of symptoms associated with the "crash" phase of cessation beyond the first few days (e.g. depression, agitation, psychosis) may indicate the presence of a concurrent psychiatric disorder requiring assessment and treatment.

4.9 Cocaine and Pregnancy

The use of crack cocaine by expectant mothers has been linked to developmental problems for their children. Cocaine rapidly crosses the placenta and has the same pharmacological effects on the fetus as on the mother (Brands, Sproule and Marshman, 1998). Research has found that prenatal exposure is associated with a higher risk of spontaneous abortion, abruptio placentae, premature birth weight, length and head circumference at birth, poor sleep patterns, and long-term behavioural problems (Gingras et al., 1995; Howard et al., 1995; Kenner and D'Apolito, 1997; Mayes et al., 1995; Regalado et al., 1996; Vogel, 1997).

Some recent studies have shown that children exposed to cocaine while their mothers were pregnant are more impulsive and easier to distract than their peers, have poor motor skills and experience language-development delays (Angelilli et al., 1994; Fetters and Tronick, 1996; Kenner and D'Apolito, 1997). These children are more difficult to arouse, but when they are aroused they are more difficult to control. This may be linked to delays in the ability to maintain attention, as well as in the ability to disengage attention (Heffelfinger, Craft and Shyken, 1997). Children with these characteristics will find it hard to learn in the school environment.

Not all researchers, however, agree that cocaine is a significant cause of developmental problems for infants exposed in utero (Kane, Aronson and Zotti, 1997). As observed earlier, poly drug use is common in cocaine-using expectant mothers, and effects observed in newborns may be attributable to use of other substances (e.g. tobacco or alcohol), as well as other factors such as poor prenatal care, inadequate maternal nutrition, poor maternal health, or other factors associated with the mother's lifestyle.

In their review of the literature, researchers from the Lindesmith Center (1998) argue that the exaggeration of cocaine effects on pregnant women may do more harm than good. The stigma, and even criminalization, of drug use may discourage women from seeking help for drug addiction, and can result in "crack kids" labels being placed on apprehended children, thereby preventing them from becoming adopted. Furthermore, cocaine-exposed children entering the school system may be inaccurately labelled as "learning delayed." However, rather than trying to disentangle the proportionate effect of cocaine versus cigarettes, alcohol, or living in poverty, the focus should be on addressing the needs of pregnant cocaine-addicted women and their affected off-spring through appropriate interventions and support.