Prescriptions for painkillers - left over from surgeries, orthopedic injuries or dental work - frequently languish unfinished in the family medicine chest.
Antianxiety medications, including the benzodiazepines known by their commercial names Xanax and Ativan, take up shelf space because they are prescribed for episodic use.
And as a growing number of adults are diagnosed with ADHD, their stimulant medication often sits alongside that of their children with attention difficulties.
Unwittingly, parents who leave these medications unsecured and unmonitored are tempting their children - and their children's friends - to try drugs they have heard and read about from schoolmates, in movies and on the Internet. In a teenager's calculation, the price is right and the risks - of scoring the drugs, at least - are low.
For parents, the antidotes to youthful rebellion and the impulse to dangerous experimentation may be complex and elusive. But making it harder for kids to lay hands on drugs with high addiction potential, say experts, is simple: Lock 'em up. The drugs, not the kids.
"In total, nearly half the prescription drugs being abused by teens originate in the homes of passive pusher parents," concluded the National Survey of American Attitudes on Substance Abuse released in August by Columbia University's National Center on Addiction and Substance Abuse.
Experts urge parents to dispose of prescription drugs that remain unused after their purpose has been served. The Office of National Drug Control Policy recommends disposing of them in the garbage bin within a coffee canister or other tightly closed opaque container, or under coffee grounds or cat litter to make exploration or retrieval less appealing.
If prescription medications need to be retained for future use, parents should keep an inventory of the drugs and secure them, either under lock and key or by keeping them where a curious child or teenager won't find them.
The stakes are high not only for teenagers and young adults but for their younger siblings as well.
The U.S. Centers for Disease Control and Prevention reported recently that deaths from drug use among young people age 15 to 24 doubled from 1999 to 2004 with the majority involving prescription painkillers.
Recently, the Annals of Emergency Medicine reported 9,147 cases of accidental ingestion of opiates by children under age 6 - for whom such medications can be lethal even at very small doses - in a 31/2-year period starting January 2003. In eight cases, death was the result.
The authors - a trio of University of Colorado Medical School researchers - believe the "poisoning of young children from prescription opioid occurs regularly," and suggests the number of children who actually found and took pain pills left out is probably much higher, since they only surveyed a portion of U.S. poison control centers to gather their data.
"The word is getting out to teens and their parents that prescription medications are dangerous when used improperly, but plenty of risk remains," says Dr. Linda Lawrence, president of the American College of Emergency Physicians.
"Adults need to monitor closely all medications in the house, and apply the same sense of caution that they would to any potentially dangerous substance."