Marijuana is the most commonly used illegal substance. However, ED visits due to marijuana use alone are rare. Some states have legalized its use for certain conditions (e.g., decrease chemotherapy side effects, glaucoma). Marijuana is a mixture of dried, shredded leaves and other parts of the Cannabis sativa plant. Marijuana is most often smoked as a cigarette (commonly referred to as a joint) or in some type of smoking device such as a bong. Marijuana may be used in combination with another drug, such as crack cocaine, and has been mixed into food such as brownies or brewed into a drink.

The main active chemical in marijuana is δ-9-tetrahydrocannabinol (THC). The effects of THC include altered perception, an inability to problem solve, difficulty thinking rationally, loss of coordination, anxiety, and tachycardia. The only treatment, if needed, is supportive until the effects wear off.

Ketamine is a rapid-acting, dissociative anesthetic that provides hypnotic, analgesic, and amnesic effects with minimal respiratory depression. ¹⁰ When given as an intramuscular injection, the onset of action is 6 minutes. The person appears to be in a coma with the eyes open. The first priority in the management of adverse effects of ketamine ingestion is protecting the airway because muscle tone is lost when an overdose of this drug occurs. Ketamine may also be considered a club drug because of its use at raves. ⁹

LSD, a hallucinogen developed in 1938, has recently become popular again in the adolescent and young adult population. ⁴ It comes as a tablet or liquid that is sold on squares of blotter paper. Effects are primarily sensory and emotional. Colors, sounds, and smells are greatly intensified. The user may hear or feel colors and all sounds. The effects can be erratic and combined with hallucinations that can be pleasurable or terrifying. Psychosis has been reported. Physical effects can include dilated pupils, hyperthermia, tachycardia, elevated blood pressure, loss of appetite, sweating, and tremors. Many users of LSD can have flashbacks, which are a recurrence of certain parts of a previous LSD experience. Flashbacks most commonly occur with chronic users but can happen to any LSD user.

PCP is a hallucinogen that alters reality, touch, hearing, smell, taste, and visual perceptions. These effects may lead to serious bodily injury to the user. Chronic and long-term use can cause permanent changes in cognitive ability, memory, and fine motor function. Pregnant women who use PCP often deliver babies with visual, auditory, and motor disturbances.

The patient under the influence of PCP may be extremely violent with an increased risk for harm to self and others. Decrease stimulation for these patients, and monitor carefully for escalating violence.

Ecstasy is a synthetic amphetamine derivative that was originally developed as an appetite suppressant in 1914. ^{4.6. and 10.} Ecstasy produces both stimulant and hallucinogenic effects and is potentially life threatening. ^{6. and 8.} As with other street drugs, ecstasy is a combination of other illicit drugs with numerous recipes used to produce it. A newer variation called herbal ecstasy is composed of ephedrine or pseudoephedrine and caffeine from the kola nut. Ecstasy comes as a tablet, powder, or capsule and in virtually any color. The drug is primarily taken orally or snorted but can also be injected or taken rectally. Imprints may or may not be present. The butterfly is the universal symbol for ecstasy and appears on drug paraphernalia used at raves. These include cigarettes and other products that do not actually contain ecstasy.

Ecstasy is one of several drugs used to facilitate sexual assault, also called “date-rape drugs.” In combination with alcohol, these drugs increase feelings of sexual arousal. This heightened sense of sexuality, coupled with short-term narrow cognitive focus, increases the likelihood that sexual assault will occur. Patients crave touch and experience a heightened sensuality, giving rise to many of the names for ecstasy such as “love” and the “hug drug.” Other effects include hyperthermia, hypertension, tachycardia, and ataxia. An ecstasy high can last up to 24 hours.

Use of ecstasy in adolescents is of significant concern: there continues to be a high rate of ecstasy abuse, which may be due to availability of the drug, as well as its intoxicating effects. All-night raves are where many users are introduced to this drug. Another factor that may contribute to increased use is the duration of the effects.

Heroin is an opiate that affects the pleasure center. In 2006 there were 91,000 first-time users of heroin, ¹¹ and the rates did not change significantly from 2005 to 2006. ¹⁰ Use of intravenous heroin (or other intravenous drug use) increases the risk for human immunodeficiency virus (HIV), hepatitis, skin abscesses/soft tissue infections, phlebitis, and bacterial endocarditis. Heroin may be intentionally used with cocaine to enhance the rush or high (speedball). The heroin dealer may also cut the heroin with other substances such as strychnine or PCP.

Heroin use can lead to physical dependence, and any attempt to stop using the drug will cause severe, painful withdrawal symptoms, including watery eyes, runny nose, yawning, loss of appetite, tremors, panic, chills, sweating, nausea, muscle cramps, and insomnia. Elevated blood pressure, pulse, respiratory rate, and temperature occur as withdrawal progresses. Heroin causes shallow breathing, pinpoint pupils, nausea, panic, insomnia, and a need for increasingly higher doses of the drug to achieve a high or to prevent withdrawal.

The heroin addict may present to the ED in acute withdrawal, after an overdose, or with problems related to intravenous drug injection. The patient in acute withdrawal is treated symptomatically with antianxiety agents, antihypertensive agents, and in some cases, administration of methadone. Acute heroin intoxication is treated with administration of naloxone, ventilatory support, and intravenous fluids when appropriate. Naloxone administration can precipitate severe withdrawal in some patients, so careful monitoring is essential.

Cocaine is a strong stimulant that can be snorted, smoked, or injected. Approximately 35.3 million Americans 12 years of age and older had tried cocaine by 2006, ^{11. and 12.} 6.1 million had used some form of cocaine in the past year, and 2.4 million admitted using it in the past month. ¹¹ Crack, the smokable form of cocaine, was introduced to the drug scene in 1986. The “high” is 10 times more powerful than that caused by snorting the drug. The associated rush or euphoria lasts only 5 to 10 minutes, which encourages more frequent use, so greater dependency develops. Many individuals addicted to cocaine say they continued to use in an attempt to experience the rush of their first time.

Injecting cocaine and other drugs carries the added risk for contracting HIV. Effects of cocaine on the cardiovascular system include chest pain, myocarditis, cardiomyopathy, endocarditis, ventricular arrhythmias, aortic dissection, hypertension, and cerebrovascular accident. Acute coronary syndrome (ACS) is the most commonly reported cardiovascular consequence of cocaine use. Other effects of cocaine are excitation, increased alertness, increased heart rate, increased blood pressure, loss of appetite, insomnia, dilated pupils, runny nose, and nasal congestion. In some situations cocaine can trigger paranoia. Cocaine may lead to seizures, cardiac and respiratory arrest, and even stroke. Long-term snorting of cocaine causes mucous membranes of the nose to disintegrate, and heavy use can actually cause the nasal septum to collapse. Despite views to the contrary, cocaine does not improve performance. Use can lead to loss of concentration, irritability, loss of memory, loss of energy, anxiety, and a loss of interest in sex.

Cocaine is also an issue in pregnancy. Literature supports the fact that cocaine, as with other drugs, can increase the risk for prematurity, stillbirth, low birth weight, central nervous system damage, and uterine rupture. Concomitant use of alcohol increases these risks and contributes to long-term developmental problems. Table 52-2 summarizes effects of maternal cocaine use on mothers and fetuses or babies.