Children in particular aren't knowledgeable about all of the dangers of prescription drugs.
Most parents don't believe their children would get high on prescribed drugs. But Markley warns, "there are a lot of smart kids who do dumb things."
"Pot is still the No. 1 drug of choice for teens. But the prescription medications and over-the-counter medication abuse is becoming much more in vogue than it was 10 years ago," Markley said.
It might not be your own child who's rummaging through the medicine cabinet, but her friend. Or even someone making a delivery who asks to use the restroom and leaves with a fistful of painkillers.
Still, there seems to be a trend that younger children are abusing meds.
"The medicine cabinet is the primary source of drugs for 12-, 13- and 14-year-olds," said John Burke of the Warren (Ohio) County Drug Task Force and president of the National Association of Drug Diversion Investigators.
It's not only prescription medicine that kids are reaching for to get a buzz, but over-the-counter meds.
"They don't really understand that something that's sold on a shelf in a store can kill them," Markley said. Students sometimes also share with pals at school. Or to make a quick buck, they peddle pills between classes.
Headlines from across the nation tell the story:
Two middle school students arrested for selling prescription drugs in Wisconsin. Two more in Iowa. Four middle school girls hospitalized after taking prescription pills at school in Florida.
"Pharm parties" are a disturbing craze in which teens steal prescription medicine from home, take the pills to a gathering, and dump the load into a bowl. The partygoers then pop the pills and wait for a reaction.
"It's like playing Russian roulette," Burke said.
It doesn't matter whether it's vitamins, Tylenol or antibiotics that get thrown into the bowl; they all have the potential to make someone sick, or worse. Add some alcohol to the mix and it makes for an even worse situation.
"I think there is the pack mentality in which kids think that there's safety in numbers, and if everybody else is doing it, it has got to be OK," Markley said.
While the children who engage in such activities do it for the thrill, others know the risks of such behavior.
"There is great danger in these parties," said Alexandria Goldie, a seventh-grader in Akron. "Some teenagers don't understand the hazards of overdosing on medicine, even if it is prescribed to them."
So, what's a parent to do?
First, explain to your child the dangers of taking prescription drugs. A Web site, notinmyhouse.com, created by The Partnership for a Drug-Free America and Abbott, includes videos and teaching tools for families interested in discussing abuse of prescription drugs.
And if your child is at a party and spots a bowl of pills, tell her to call for help. You can even agree on a "code" term that means "pick me up immediately."
Once you get your kid in the car, don't scold.
"If your child is savvy enough to call ... the parents should praise a child for getting themselves out of the situation. Turning it into an interrogation will backfire," Markley said. "Next time they will not call."
Burke, who travels throughout the United States delivering the message about drug diversion, tells parents to hide prescription medications.
"Parents are scared a lot of times to sit their kids down and talk to them about these things because they think they will put ideas into their heads. The thing is - these ideas are already out there," Markley said. "It's the parents' duty to tell them what they are hearing is wrong. That (abusing prescription) drugs are not safe.
"They can kill you."