Drug types: depressants (barbiturates, benzodiazepines, opiates, opioids)

Depressants generally have the opposite effect of stimulants. Many depressants are used as sedatives or tranquilizers, terms often used as if they mean the same thing even though some experts would dispute such interchangeable usage of the terms sedative and tranquilizer. Depressant drugs slow a person down, and one result can be reduction of tension, which in turn can improve a mentally depressed mood. Depressant withdrawal symptoms typically include uneasiness and sleeping difficulty. If dependence is strong enough, withdrawal may also involve tremors, loss of strength, delirium, and seizures. Gradual reduction in dosage may help avoid withdrawal symptoms, but much depends on the particular drug and the strength of dependence.

Specific depressants not listed among the following classes: alcohol, chloral hydrate, ethchlorvynol, GHB, glutethimide, ketamine, mandrake, meprobamate, methaqualone, PCP, pentazocine, zaleplon, and zolpidem.

Barbiturate Class (Barbiturates)

Barbiturates were introduced into medical practice during the early 1900s, for combating insomnia, anxiety, and seizures. Despite occasional flurries of concern, not until the 1960s did much alarm grow about barbiturates in the United States. Members of a U.S. Senate subcommittee began portraying the drug class as a menace in the 1970s, and afterward stricter controls were put on use.

Barbiturates and alcohol have similar effects. If someone intoxicated by alcohol takes barbiturates, the drunkenness will deepen as if more alcohol had been swallowed. Pharmaceutical effects of alcohol alone can kill a person who overdoses, and adding barbiturates can transform a session of social drinking into a fatal one. More than one person has died by taking barbiturate sleeping pills with alcohol instead of water.

The similarity of alcohol and barbiturates is also shown by the appearance of a serious withdrawal syndrome called delirium tremens in alcohol and barbiturate abusers who are cut off from their drug. Lesser withdrawal symptoms for both drugs may include perspiring and vomiting. Barbiturate withdrawal may involve dizziness, tremors, fidgety behavior, edgy feelings, and insomnia. Even with strict medical supervision, withdrawal can be fatal. Tolerance can develop. More details can be found in alphabetical entries for specific barbiturates.

A person using barbiturates should take the same precautions as a person using alcohol, for example, using care about running dangerous machinery such as automobiles.

Barbiturates can cause reflex sympathetic dystrophy of the arm, a disease in which a hand loses bone density and becomes painful and difficult to move. This class of drugs may also cause a syndrome that produces pain in the shoulder and hand, interfering with their movement. Extended dosage with barbiturates may cause rickets, a disease in which bones soften. One of the most dangerous effects of barbiturate overdose is temporary stoppage of electrical activity in the brain, which could lead to premature declaration of a patient’s death, particularly if the patient is being treated for some injury without caregivers knowing about the person’s barbiturate usage.

This class of substances may interfere with blood thinner medicine, with birth control pills, and with other female hormone medications. Barbiturates may extend the time that an MAOI dose lasts.

In animal experiments barbiturates have encouraged the development of cancer.

When used by pregnant women, barbiturates can cause birth defects ranging from internal organ deformities to malformations of the face. If a pregnant woman uses barbiturates regularly, her offspring may be born resonant with them. This class of drugs passes into the milk of nursing mothers and may depress consciousness, pulse rate, and respiration of nursing infants.

Specific barbiturate class depressants: butalbital, mephobarbital, pentobarbital, and phenobarbital.

Benzodiazepine Class

Benzodiazepines became widely available for medical purposes in the 1960s and replaced barbiturates in treatments of many conditions. Benzodiazepines proved themselves less prone to abuse than barbiturates, in addition to being safer-accidental overdose is unlikely because the amount needed for a medical effect is so much smaller than a poisonous amount. In addition to reducing anxiety, benzodiazepines may improve quality of sleep-from fighting insomnia to eliminating sleepwalking. This class of drugs is also used to calm people and to treat convulsions. Some users experience mild euphoria.

As might be expected with drugs that promote sleep, benzodiazepines can worsen reaction time, vigilance, and thinking abilities and therefore should be used cautiously if a person is operating dangerous machinery such as an automobile. Problems may also develop for persons who are already unsteady on their feet, such as elderly persons prone to falling. The substances can also cause memory trouble, typically difficulty in recalling recent experiences. Headache, peevishness, confusion, and tremors may occur. In unusual cases rageful outbursts may occur. These are “paradoxical reactions,” meaning they are the opposite of what would be expected from the drug. Expressions of rage possibly emerge because the drug reduces anxiety in a person who is angry about something, and less anxiety can lead to less inhibition against doing something.

Over a 12-year span a practitioner observed patients taking benzodiazepines to treat serious sleep problems such as night terrors and sleepwalking. The practitioner found that 2% of this population (not 2% of all patients but just those using benzodiazepines against these sleep disorders) occasionally abused them, and this population base included persons with a previous history of drug abuse; thus we can expect benzodiazepine abuse to be even lower in a general population. Among persons treated for drug abuse, benzodiazepines are among the least-abused substances. Experiments giving free access to benzodiazepines to persons undergoing treatment for drug abuse revealed little interest in those compounds. This class of depressants can be highly popular among special populations, however. One study noted that 30% of alcoholics were using benzodiazepines. When benzodiazepines were given to rats in experiments, the animals’ consumption of alcohol increased, suggesting that human benzodiazepine usage might increase alcohol’s appeal. Although benzodiazepines are administered to treat alcohol withdrawal, combining the two substances recreationally is a dangerous mix that can prove fatal.

Different benzodiazepines have differing attractiveness to abusers. Measured by amount of misuse, claims made by misusers about drug effects, mental and physical effects verified in scientific experiments, and impressions reported by medical caregivers, diazepam is considered to have one of the greatest potentials for abuse. Alprazolam and lorazepam have similar, but lower, risk. Halazepam and oxazepam seem to be among the least risky for abuse.

Tolerance to some benzodiazepine effects can develop (many details are in this book’s alphabetical section). Dependence can also emerge, with a withdrawal syndrome similar to those of alcohol and barbiturates. Often the syndrome may be avoided by gradual reduction of dosage.

Small studies have found that women who use benzodiazepines during pregnancy produce infants who are smaller than normal. Children in one of these studies rapidly caught up in some growth perimeters, but at the age of 18 months head size still remained smaller than normal. Facial deformities were common. The children had persistent trouble with muscle control. Similar findings in another small study included mental retardation, but still another study noted that such children also had heavy fetal exposure to alcohol, exposure that is known to produce mental retardation. Thus the actual role of benzodiazepines was unclear.

Some of these reports did not track outcomes past infancy. Research tracking children up to four years of age found that early problems attributed to benzodiazepines cleared up in most of them. When teachers were asked to evaluate schoolchildren who had fetal exposure, the instructors found no difference between them and classmates.

Researchers who investigated the outcome of thousands of pregnancies found no evidence that benzodiazepines cause cleft palate. A large study involving hundreds of pregnancies found birth defects to be no more likely among women who used benzodiazepines than among women who did not use them; and even when malformations occurred, no particular kind of birth defect tended to appear in benzodiazepine offspring. Drugs that cause fetal harm generally cause particular types of damage; lack of a particular type with benzodiazepines suggests that the drug was not the cause of observed
malformations. Some investigators believe they have detected a particular birth defect pattern, but such findings have been questioned. As the twenty-first century began, a research team reported evidence that benzodiazepines may damage fetal brain development. Science has not yet rendered a verdict on the safety of benzodiazepines during pregnancy. Infants with fetal exposure can be born dependent on this type of drug. It passes into breast milk, but the amount from lower-dosage levels probably has no effect on nursing infants.

Specific benzodiazepine class depressants: alprazolam, chlordiazepoxide, clonazepam, clorazepate, diazepam, estazolam, flunitrazepam, flurazepam, halazepam, lorazepam, midazolam, oxazepam, prazepam, quazepam, temazepam, and triazolam.

Opiate Class

Along with alcohol, opiates are the oldest known depressants. At one time the term narcotic referred specifically and only to opiates, but when drug control laws were strengthened in the early twentieth century the language of those laws expanded the dictionary definition of narcotic and made it a synonym for all controlled drugs.

Although opiates have various medical uses, the main therapeutic application is pain control. Other common uses are for fighting coughs and reducing diarrhea. Some other therapeutic uses of specific opiates are given in this book’s alphabetical listings of drugs.

The chance of medical opiate usage turning a person into an addict is slim. Very few persons receiving medical opiates find them attractive, and almost all patients who enjoy opiates already have a drug abuse problem. Researchers examined records of 11,882 patients who received narcotics and found 4 with a subsequent addiction problem who lacked a prior drug addiction history. The chance of developing dependence is higher, but a patient can be weaned off opiates in ways that avoid withdrawal symptoms.

Illicit users of opiates generally seek to achieve a mental state of indifference in which problems and frustrations no longer feel bothersome. A person high on opiates is oblivious to the world and unlikely to bother anyone. Some users experience euphoria.

Classic unwanted actions from opiates are constipation, urinary difficulty, low blood pressure, and breathing trouble. MAOI drugs, described earlier, may interact dangerously with opiates. In contrast to such problems, a desirable drug interaction is that opiates may boost pain relief from aspirin. Originally the phrase “being hooked on a drug” referred to being so resonant with (that is, dependent on) an opiate that a withdrawal syndrome occurred if dosage stopped. Symptoms of opiate withdrawal are similar to those of influenza: sweats, goose bumps, muscle aches, cramps, runny nose, diarrhea, and sleep difficulties. Although conscienceless and irresponsible addicts may be particularly short-tempered and dangerous if undergoing withdrawal, for other persons the experience is miserable, but not horrible, and usually lasts only a few days. Traditionally those few days are the extent of withdrawal, but some authorities believe a subsequent stage of withdrawal occurs in which a person experiences aches, insomnia, and grouchiness for several months. Such symptoms, however, may simply be signs that the psychological buffer provided by opiate use is no longer available.

Drug addiction “maintenance” programs are designed to supply enough drug to hold off withdrawal but not enough to produce recreational sensations. Unless participants supplement the legal dosage with illicit supplies, such persons will not experience opiate effects enjoyed by addicts. Someone on a maintenance dose can adequately perform job duties and safely operate a motor vehicle.  Performance may not be as sharp as in a drug-free state, but performance is in the normal range.

Opiates have a wide range of effects on fetal behavior. If a pregnant woman uses opiates regularly the fetus soon adapts to the presence of the drug and seems to develop normally, although an infant can be born resonant with (that is, dependent on) the drug and undergo withdrawal. Intermittent use of opiates is more damaging to a fetus than regular use, with the changing drug environment causing extra stress as a fetus copes with one condition and then another. Opiates cause fetal metabolism to increase, diverting energy away from body development. Infants born to opiate users are commonly smaller than normal, and early slowness of brain development has been observed. Evidence exists that fetal exposure causes long-lasting problems in children, involving impulsiveness and inattention, but some researchers feel that home environment (often involving a single-parent opiate abuser with additional problems) is a better explanation for those difficulties.

Specific opiate class depressants: buprenorphine, codeine, dihydrocodeine, etorphine, heroin, hydrocodone, hydromorphone, morphine, nalbuphine, opium, oxycodone, pholcodine, and thebaine.

Opioid Class

Opioids are often called opiates, which is satisfactory for practical purposes because the two classes of drugs basically produce the same effects in the same way. A technical difference exists between the two classes, however. If the history of a product were traced backward through its manufacturing processes, opiates generally would begin with the opium plant, but opioids would generally begin in a laboratory. Despite this technical distinction, the terms opiates and opioids are often used synonymously. Some of these substances are called “semisynthetic” and are referred to as “opiate/opioid.”
Some opiates, such as morphine, can even be manufactured wholly in a laboratory without starting from the natural product opium; thus the same chemical can be either an opiate or an opioid.

Specific opioid class depressants: butorphanol, dextromethorphan, dextromoramide, dextrorphan, diphenoxylate, dipipanone, fentanyl, ketobemidone, LAAM, levorphanol, meperidine, methadone, oxymorphone, phenoperidine, piritramide, propoxyphene, remifentanil, and trimeperidine.