The use of prescription painkillers recreationally is at epidemic levels, according to the Centers for Disease Control and Prevention. What is it about the pills that makes them so dangerously addictive and a potential gateway for heroin?
The surprising answer, at least to many non-medical professionals, is that the common painkillers that doctors and dentists prescribe to patients after injuries and surgeries have the same active ingredient as the drug that alleyway users inject into their arms. And both act in similar ways on the human brain to produce a sense of pleasure that can overwhelm its reasoning functions.
While many who abuse prescription painkillers think of heroin as a low-class drug that will never make its way into their lives, they don’t realize, they’re already addicted to a form of it.
Prescription painkillers of the sort that 12 million Americans used nonmedically in 2010, according to the CDC, are narcotic opioid drugs, more commonly referred to as opiates. They include hydrocodone and oxycodone, also known by the brand names Vicodin and Oxycontin, respectively.
Reward system
According to the National Institute on Drug Abuse, when opiates are consumed, they enter the bloodstream and activate neurotransmitter receptors in the brain’s reward system. Scientists call the link between the drug and the receptor a lock and key relationship, because one specific neurotransmitter activates specific receptor molecules, the same way only one key fits a particular lock.
When the opiates reach the opiate receptors, the latter release the hormone dopamine. The dopamine – which acts as an “excitatory neurotransmitter” – produces feelings of pleasure and satisfaction. It’s this action at the most basic cellular level that provides the foundation for drug addiction.
Although the initial effect of the drug is rewarding and results in a “high,” or feeling of euphoria, the effect is time stamped. When it wears off, the user feels much worse than before having taken the drug.
Addiction psychiatrist Dr. Stuart Gitlow, president of the American Society of Addiction Medicine, compares this phenomenon to alcohol use, saying that people drink for the immediate effect, regardless of the inevitable hangover that will follow.
"The only connection a patient makes is that use of the drug leads to immediate relief -- not the longer-lasting discomfort that follows. Unfortunately, the drug causes both the immediate relief and the following discomfort. As time passes, the discomfort becomes more apparent than the relief and the drug is used merely in an effort to avoid the discomfort that the drug has caused in the first place."
Gitlow explains that humans are not biologically programmed to think about cause and effect in this way. “The only thing a patient connects in their head is with the immediate relief -- not the effect felt days later,” he said.
Also, as with alcohol, the pleasurable effect diminishes over time, he said.
At the cellular level, chronic activation of the opiate receptors eventually saturates them -- requiring higher and higher dosages of the drugs to achieve the same pleasant feeling. It is for this reason that an addict will seek more potent forms of the opioids.
“There are certain medications that invite an escalation to more serious drugs and narcotics and opiates are two of those” said Dr. Nancy Snyderman, NBC News chief medical editor.
The speed with which the different forms of opiates enter the bloodstream and flood receptors depends on the form in which it’s consumed, explains Snyderman. Consuming a pill by mouth can take up to a few hours to have an effect because it has to be digested by the stomach and intestines before it makes its way into the bloodstream. Injection is the second-fastest way to achieve the desired effect, as the drug enters the bloodstream instantly but has to make its way to the brain. Snorting a crushed pill or a powder crosses the blood-brain barrier in a matter of seconds; that’s what makes snorting so addicting and the drug delivery system of choice.
It also means there’s less margin for error if a person has a drug reaction or overdoses, Snyderman said.
In an opiate overdose a person may experience confusion and physical discomfort. In severe cases, a person’s breathing can slow down so much that breathing stops, resulting in a fatal overdose. The CDC estimates that more than 100 people die every day from unintentional drug overdoses -- many of them involving prescription pain killers.
In addition to the immediate effects produced by the drugs, numerous short- and long-term side effects can be associated with opiate use and abuse.
Among the most common side effects reported are constipation, nausea and what’s known as pin-point pupils. As an addict increases consumption, the side effects become more severe and can include extreme sleepiness and slowed respiration and pulse rates.
The most widely known side effect is the physical dependence that occurs with long-term use.
Dr. Joe Gay, director of Health Recovery Services in Ohio, points out that “As tolerance goes up, susceptibility to withdrawal becomes a real factor.” Withdrawal symptoms can be excruciating and including muscle aches, anxiety, sweating and insomnia, to name a few.
Like any addiction, opiate abuse is considered a relapsing brain disease. While you can’t predict whether a given person will become addicted to drugs or not, certain factors can increase a person’s risk, including genetic makeup, environment, socioeconomic status, and others, researchers say.
One example comes out of a new study from the Seattle Children’s Research Institute, in the June issue of the Journal of Adolescent Health. It found that adolescents and young adults with mental health disorders were about 2 ½ times more likely to become long-term opioid (synthetic opiate) users that their peers without such disorders.
Msnbc.com contributor Rita Rubin also contributed to this report.
Read more of NBC's special report:
Crackdown on painkiller abuse fuels new wave of heroin addiction