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Module 3
Drugs in the Cupboard
Background
PRESCRIPTION DRUGS
Drugs prescribed by a physician can relieve pain and control the symptoms of many disorders and diseases. People who use prescription drugs as directed by a doctor (at the prescribed dose and for the recommended length of time) are at very low risk for addiction or other negative side effects. However, intentional misuse of prescription drugs can be dangerous. Three commonly abused prescription drugs are opioids, central nervous system (CNS) depressants, and CNS stimulants.
The Internet makes prescription drugs more easily accessible for abuse. E-mail inboxes are often full of spam e-mails offering the sale of prescription drugs without a prescription. When discussing these drugs with your students, bring up the topic of dangerous and misleading spam e-mails, and how it is important to respect prescription drugs.
Effects of Prescription Drugs on the Brain and Body
Opioids
Opioids, such as morphine, codeine, oxycodone (Oxycontin), and hydrocodone (Vicodin), are prescribed for pain relief. Used correctly, opioids are helpful for people suffering from chronic pain or pain from surgery. These drugs act by attaching to opioid receptors in the brain and spinal cord, and blocking the transmission of pain messages to the brain. Opioids also cause initial feelings of pleasure by acting on the reward system in the brain. Side effects of opioids include drowsiness and constipation.
CNS Depressants
CNS depressants include barbiturates and benzodiazepines (e.g., diazepam [Valium], alprazolam [Xanax], and lorazepam). These medications are prescribed to treat anxiety, tension, and sleep disorders. They slow brain function by increasing the activity of the neurotransmitter GABA. GABA decreases brain activity and causes feelings of drowsiness and calmness, which is helpful in people with anxiety or sleep disorders.
CNS Stimulants
CNS stimulants, such as dextroamphetamine (Dexedrine) and methylphenidate (Ritalin), are prescribed for attention-deficit hyperactivity disorder (ADHD), narcolepsy (a sleeping disorder), and depression that has not responded to other treatments. Stimulants copy the activity of the neurotransmitters dopamine and norepinephrine by stimulating their specific receptors. This results in increased alertness, attention, and energy. Stimulants also result in increased feelings of pleasure, higher blood pressure and heart rate, and increased blood glucose levels.
Scientists propose that there is less dopamine transmission in the brains of persons with ADHD when compared to other individuals. Because stimulants correct this shortfall, individuals with ADHD are at low risk for becoming addicted to stimulant medications. Individuals that have not been prescribed Ritalin abuse the drug by swallowing the tablets or by crushing and then snorting them. This causes wakefulness and euphoria. In people who do not need the medication, the increased dopamine transmission caused by ingesting Ritalin can be highly addictive.
| Opioids |
Drug Effects |
| Morphine, Codeine, Oxycodone, Hydrocodone |
Attach to opioid receptors in the brain and body to block transmission of pain messages. |
| CNS Depressants |
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| Barbiturates and Benzodiazepines |
Slow brain function by increasing the activity of the neurotransmitter GABA, which decreases brain activity and causes feelings of drowsiness and calmness. These drugs also decrease heart rate and blood pressure. |
| CNS Stimulants |
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| Dextroamphetamine and Methylphenidate |
Activate dopamine and norepinephrine receptors, which results in increased alertness, attention, and energy. Stimulants also cause higher blood pressure and heart rate. |
Prescription Drugs in Combination with Other Drugs
In order to be safe and healthy, patients taking prescription drugs must comply with the medication guidelines set by their doctor. It is important to know how much medicine to take, how long to take it, and what else can have an impact on its effects on the body. Possible interactions with other drugs, vitamins, certain activities, or environmental factors such as sun exposure need to be thoroughly understood by the patient for the prescribed medication. Prescription medications should never be shared.
Misusing prescription drugs can have very negative consequences. At large doses, opioids can be fatal because they can cause heart and breathing rates to slow down or stop. High doses of stimulants can cause an irregular heartbeat, seriously high body temperatures, and the potential for heart attacks and death. Taking stimulants in combination with over-the-counter cold medications can cause abnormalities in blood pressure and heart rhythm. Taking opioids and CNS depressants in combination with other drugs, such as alcohol or antihistamines, can cause severe respiratory problems and death.
Prescription Drug Withdrawal
Long-term abuse of prescription drugs may cause addiction and produce withdrawal symptoms if the drug is discontinued. The withdrawal symptoms from prescription drug abuse vary, depending on the particular drug being abused. The withdrawal symptoms that result from opioid abuse include restlessness, insomnia, vomiting, muscle and bone pain, diarrhea, and cold flashes with goose bumps.
Withdrawal from CNS depressants may cause the brain’s activity to rebound and race out of control, resulting in seizures and other harmful consequences. The withdrawal symptoms of CNS stimulants include depression, fatigue, insomnia, loss of appetite, and craving for more stimulants.
INHALANTS
Inhalants are a class of chemicals that have many useful purposes in households but were never meant to enter the body. They are intentionally misused by sniffing or inhaling. They can be sprayed directly into the nose or mouth, inhaled from substances dropped into a bag (“bagging”), inhaled from a soaked rag (“huffing”), or inhaled from a balloon. Inhalants enter the bloodstream directly through the lungs and rapidly travel to the brain. Users experience an immediate “head rush” or high.
Many inhalants are commonly found in the home. They can be classified into four categories: volatile solvents, aerosols, gases, and nitrites.
The student materials for this module do not mention specific household products. This was intentional. Young people are often highly curious about these easily accessible drugs. To guard against such curiosity, we recommend you avoid mentioning specific products in your discussion. They are listed in the following chart for your information only.
Volatile solvents
Paint thinners and removers, dry-cleaning fluids, degreasers, gasoline, glues, correction fluids, felt-tip marker fluids.
Aerosols
Sprays containing propellants and solvents, including spray paints, deodorants and hair sprays, vegetable oil sprays for cooking, fabric protector sprays, whipped cream.
Gases
Household gases and medical anesthetics: ether, chloroform, halothane, nitrous oxide (laughing gas).
Nitrates
Cyclohexyl nitrite, isoamyl (amyl) nitrite, isobutyl (butyl) nitrite; sold under the name of “poppers,” or found in certain room deodorizing sprays.
Inhalant abuse can damage areas of the brain involved in cognitive functions and produce symptoms ranging from mild impairment to dementia. Inhalant abuse can also damage brain areas responsible for movement and vision.
Permanent hearing loss and irreversible damage to nerves throughout the body can occur from using inhalants. Inhalants can cause hepatitis, liver failure, and muscle weakness. They also interfere with the production of red blood cells, which can result in a life-threatening condition known as aplastic anemia. A condition called “sudden sniffing death” may occur when inhaled fumes replace oxygen in the lungs and brain and cause suffocation. Finally, inhalants can interfere with heart rhythm, leading to a heart attack. This can occur from a single session of repeated inhalant use.
Effects of Inhalants on the Brain
Scientists are investigating the exact way in which inhalants slow and stop the activities of neurons. Some inhalants also damage the structure of the brain, particularly the myelin, or insulation, that covers the axons. Because myelin helps messages travel through the neurons, this damage can be very serious. The parts of the brain most affected by inhalants are the cerebral cortex, cerebellum, hippocampus, and brain stem. Because of the damage to the cerebellum, heavy users of inhalants often show signs of decreased coordination, moving slowly and clumsily.
The frontal cortex of the brain, important for solving problems, and the hippocampus, a part of the brain involved in memory, are also affected by inhalant abuse. Researchers think that inhalants deprive the brain of oxygen. This causes the death of nerve cells and a decrease in nerve cell activity. Thinking, memory, and the ability to learn are all negatively affected.
Many inhalants activate the brain’s reward system and stimulate the release of dopamine. This is thought to be responsible for the pleasurable feelings associated with inhalant use.
Long-Term Inhalant Abuse
People who use inhalants over a long period of time feel a strong urge to continue using them. Effects of long-term abuse include weight loss, muscle weakness, disorientation, inattentiveness, lack of coordination, irritability, and depression.
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Contact Information
For questions regarding NIDA's Science Education Program and Materials, contact Cathrine Sasek, Ph.D., e-mail: csasek@nih.gov.
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