Taking prescription drugs in a way that hasn't been recommended by a doctor can be more dangerous than people think. In fact, it's drug abuse. And it's illegal, just like taking street drugs.

Why Do People Abuse Prescription Drugs?

Some people abuse prescription drugs because they think they will help them have more fun, lose weight, fit in, and even study more effectively. Prescription drugs can be easier to get than street drugs: Family members or friends may have them. But prescription drugs are also sometimes sold on the street like other illegal drugs.

But prescription drugs are only safe for the people who have prescriptions for them. That's because a doctor has examined these people and prescribed the right dose of medicine for their medical condition. The doctor has also told them exactly how they should take the medicine, including things to avoid while taking the drug. They also are aware of side effects and can watch patients closely for these.

Which Drugs Are Abused?

The most often used prescription drugs fall into three classes:

1. Opioids

• Examples: oxycodone (OxyContin), hydrocodone (Vicodin), and meperidine (Demerol)
• Medical uses: Opioids are used to treat pain.
• How they work: Opioids attach to opioid receptors in the central nervous system (the brain and the spinal cord), preventing the brain from receiving pain messages.

2. Central Nervous System (CNS) Depressants

• Examples: phenobarbital (Luminal), diazepam (Valium), and alprazolam (Xanax)
• Medical uses: CNS depressants are used to treat seizures, anxiety, panic attacks, and sleep disorders.
• How they work: CNS depressants slow down brain activity by making changes in brain chemicals. The result is a drowsy or calming effect.

3. Stimulants

• Examples: methylphenidate (Ritalin) and amphetamine/dextroamphetamine (Adderall)
• Medical uses: Stimulants can be used to treat ADHD and other conditions.
• How they work: Stimulants increase brain activity, resulting in greater alertness, attention, and energy.

What Are the Dangers of Abusing Medicines?

Like all drug abuse, using prescription drugs for the wrong reasons has serious risks for a person's health.

Opioid abuse can lead to mood and behavior changes, trouble thinking clearly, breathing problems, and even a coma or death. This risk is higher when opioids are taken with other substances like alcohol, antihistamines, and CNS depressants.

CNS depressant abuse is risky too. Depressants can make people sleepy, uncoordinated, or confused, and can lead to slurred speech and slowed breathing. Abruptly stopping or reducing them too quickly can lead to seizures. Taking CNS depressants with other medicines, such as prescription painkillers, some over-the-counter cold and allergy medicines, or alcohol can slow a person's heartbeat and breathing — and even kill.

Stimulant abuse (like with some ADHD drugs) may cause heart problems, seizures, panic attacks, paranoia, and violent behavior. These risks increase when stimulants are mixed with other medicines — even ones you can buy without a prescription, like cold medicines.

The dangers of prescription drug abuse can be even worse if people take drugs in a way they weren't intended to be used. Ritalin may seem harmless because it's prescribed even for little kids with ADHD. But when a person takes it either unnecessarily or in a way it wasn’t intended (such as snorting or injection), serious problems can happen.

Probably the most common risk of prescription drug abuse is addiction. People who abuse medicines can become addicted as easily as if they were taking street drugs. That's one reason most doctors won't renew a prescription unless they see the patient — they want to examine patients to make sure they're not getting addicted.

Tips for Taking Prescription Medicine

If a doctor prescribes a pain medicine, stimulant, or CNS depressant, follow the directions exactly. Also be sure to:

• Go to all doctor's visits. Your doctor will want you to visit often so they can see how well the medicine is working for you and adjust the dose or change the medicine as needed.
• Make a note of the effects the drug has on your body and emotions, especially in the first few days as your body gets used to it. Tell your doctor about these.
• Keep any information your pharmacist gives you about any drugs or activities you should steer clear of while taking your prescription.
• Never increase or decrease the dose of your medicine without checking with your doctor's office first.

Finally, never use someone else's prescription. And don't let anyone use yours. Not only are you putting others at risk, but you could suffer too: You won’t be able to refill a prescription early if the medicine gets used up before it should be. And if you're found giving medicine to someone else, it's considered a crime.