NEW YORK (CNN) -- A dozen old family photos were strewn across the table as Gary Neal picked them up one by one.
The attorney from Tulsa, Oklahoma, reminisced about his teenage son, Harrison, who died two years ago at the age of 17 after fatally mixing over-the-counter cold medication and someone else's prescription painkillers.
"There's nothing worse as a parent than to see your kid on a gurney being rolled out of your house ... and placed in a hearse," Neal, 61, lamented. "There's nothing worse than that."
Hoping to get the word out that in the wrong hands, prescription drugs can be deadly, Neal joined forces this year with the New York-based Partnership for a Drug-Free America.
"We have 20 percent of our teenagers, one in five, who have admitted to abusing a prescription medication," said Steve Pasierb, president of the organization. "We know that is based on their attitudes and beliefs that this is safer."
Pasierb's group, along with drug maker Abbott, launched an anti-drug campaign this summer called Not in My House. Health Minute: Watch more on one father's quest to raise awareness »
The Internet-based educational campaign is aimed at educating not just teens but their parents about the dangers of prescription medications.
"This is unlike any drug issue we've ever dealt with," Pasierb explained. "Supply can be controlled in our own house. We're not talking about Afghanistan or Colombia. We're talking about your house and my house."
Neal learned that his son started experimenting with drugs such as marijuana when he was 15.
"It was one of those things I wasn't happy about, but I didn't think it was the end of the world."
Neal restricted Harrison's after-school activities, but he said that when the behavior continued, he ordered his son to submit to home and professional drug tests. He also enrolled Harrison in an outpatient drug treatment program the summer before his death.
Neal suspected that the problems weren't behind them, but he was unaware that the teen was abusing prescription drugs.
"I don't think he knew that his abuse of these prescription drugs would be deadly," Neal added.
That's part of the problem being addressed by Pasierb's group.
"It's this belief that they've found something safe. 'Grandma uses it. I can take a couple from her bottle,' " Pasierb explained. "When they're not used with a prescription and the way they are intended, prescription drugs can be every bit as dangerous, every bit as addictive, every bit as deadly as illegal street drugs."
What's more, Pasierb said, "Over the past eight to 10 years, adolescent substance abuse, teen drinking and teen smoking have all been in a steady decline. The only thing that has been resistant to that progress has been prescription drug abuse."
Pasierb put part of the blame on parents. The drugs of choice when they were young tended to be illegal ones: marijuana, heroin, cocaine.
"This idea of purposely abusing prescription drugs didn't go on when they were teenagers themselves," he said.
Part of the Not in My House campaign appeals directly to parents to take action starting with their own medicine cabinets.
"When we get them the message, a light bulb goes off and they are immediately mobilized," Pasierb said. "They go home, they clean out their medicine cabinet ... and they talk with their kids."
Specifically, the Not in My House campaign recommended that parents take an inventory of prescription medications at home, counting pills left in the bottle or package after every use.
Medications should be stored in a safe place that is not readily accessible to everyone in the house.
Finally, leftover or expired prescription pills should be disposed of properly.
Experts cautioned not to flush medications down the toilet where they could harm the water supply but to place drugs in a an opaque container with something unpleasant mixed in, such as cat litter. The bottle should be sealed and placed in the trash.
With the second anniversary of Harrison Neal's death approaching, his father still has a lot of questions and doubts. "Could I have done it better? Could I have done it different? Would the results have been different? You never know the answers to those questions because you never get a second chance.
"I've lamented his death every second since he died and will live with it the rest of my life."