Many teens think that these drugs are safe because they have legitimate uses and are often found at home in the medicine cabinet… Teenagers generally lack a sense that OTC and prescription medications can be dangerous or addictive… Some teenagers who abuse prescription medications and OTC preparations are sensation seekers, they "use" to get high, or are seeking to self-medicate. [from an article on Medscape, sorry no link]
Remember “Parents are the anti-drug”, but:
Parents may simply not be aware of the consequences of this type of abuse. Despite the increase in parent-teen discussions about the risks for drugs, many parents may not be discussing the risks of abusing prescription and OTC medicines with their children. Only 24% of teens have reported that their parents had talked with them about the dangers of abusing prescription drugs or the use of medications outside of a clinician's supervision, and just 18% of teens have indicated that their parents had discussed the risks of abusing OTC cough medicine [from an article on Medscape, sorry no link]
The key for parents:
The Partnership for a Drug-Free America recommends a 3-step approach: (1) educate [themselves about these and other teen “dangers”]; (2) communicate [with your preteen and teen, factually and repeatedly]; and (3) safeguard [limit access to what you must have in your home and get rid of the rest].