A drug for all addictions: Can science find the panacea addicts can’t?
As researchers dig to uncover secrets, treatment opportunities emerge
Imagine prescribing a drug that treats addiction, and then following the pharmacokinetics and patient outcomes in a pharmacist-run clinic. The drug would not just treat nicotine or cocaine dependence. In fact, it wouldn’t be substance-specific at all. Rather, it would treat the condition of being addicted. Call it pan-addiction pharmacotherapy.
This scenario isn’t as far off as you might think. Research is now under way to uncover the common denominators of addiction, says Frank Vocci, PhD, director of the Medications Development Division at the National Insti tute on Drug Abuse (NIDA), a branch of the National Institutes of Health (NIH). If scientists can find the key to those commonalities, he says, the development of an all-addiction pharmacotherapy will be possible. The secrets of this all-addiction therapy are locked away in the brain somewhere. So far, therapists know to target specific regions of it to treat addictions to particular substances, much the way other clinicians treat depression.
For now, the drugs being developed counter specific narcotic or prescription pill addictions. And the numbers keep growing. There are proven pharmacotherapies for treating alcoholics, heroin addicts, and smokers. Some are like vaccines, using the elements of the drugs themselves to slowly counteract physical cravings. Others work by blocking the specific brain receptor that induces cravings or signals that it needs more of a specific drug. Methadone for heroin addiction, for example, is a synthetic opiate agonist that mimics the actions of heroin to relieve intense cravings and withdrawal symptoms. LAAM (levo-alpha-acetyl-methadol) is another opiate agonist the U.S. Food and Drug Administra tion approved for the treatment of heroin addiction in 1993.
"Opiates produce a change in the person’s brain, and, eventually, the brain functions better with a narcotic agonist on board, whereas the antagonist drugs can worsen some withdrawal symptoms," says Vocci. "They work even better for highly motivated patients," he adds, pointing out that behavioral changes are needed to kick a drug addiction.
Another potential option for heroin addicts, buprenorphine, is currently under review by the FDA. It is related to morphine but is a partial agonist, meaning there is a limit to how much can be dosed. But the drug has been found to be less likely to cause respiratory depression, a major toxic effect of opioids, making the drug’s safety profile endearing to researchers.
What else is on the horizon? Perhaps a badly needed pharmacotherapy for cocaine addiction. Within the next year, two Phase III studies are planned for the drug selegeline. Two forms will be evaluated: a transdermal patch and an immediate release tablet.
Merging addiction clinics, pharmacies
Of course, the average hospital pharmacist probably has never filled a prescription for LAAM or methadone for heroin dependence, although some may have seen methadone prescriptions for pain. That’s because the current clinic-based distribution system only allows regional AMA-registered doctors and pharmacies associated with addiction clinics to dispense these drugs. But new efforts are under way to change that. This past July, proposed rule changes were presented to the Department of Health and Human Services by agencies like Vocci’s, asking for comments on revising the current treatment system. Vocci says federal oversight of the clinics could be replaced by an accreditation/certification system similar to that of the Joint Commission on the Accreditation of Healthcare Organizations, but on a smaller scale.
"The [addiction] clinic system has isolated the treatment of the patient with a narcotic agonist. It has separated [the patient] from the medical system. Three-fourths of opiate users are not in treatment, partly because they feel stigmatized by going to a clinic," he says.
Vocci says the proposal is comprehensive, with provisions for certification and treatment standards, even program staffing. If there is office-based therapy with methadone and LAAM, hospital pharmacists someday could fill dispensing orders or get involved with clinic operation.
Vocci says the other push in addiction therapies is to be more successful at moving new treatments from research to the clinic or hospital. NIDA is setting out to bridge the gap by showing physicians and pharmacists in the trenches that therapies developed at research institutions will work for them. The agency is setting up a Clinical Trials Network (CTN), which will bring researchers and practitioners together as partners to conduct narcotic addiction treatment studies.
Researchers will write manuals on how to perform new addiction treatments, which practitioners will use and then report their results. In that manner, the "real-world effectiveness" of treatments can be evaluated, and the ones that work best can be incorporated into a clinic’s treatment repertoire. Some of these studies will involve pharmacotherapies. CTN will be in its organizational phase for the next year, then studies will begin.
As new opportunities for clinical pharmacists emerge, patient addiction should be on a hospital pharmacist’s radar screen. Suppose a shipment of Percodan never makes it to your pharmacy. Or the bottle of Xanax you just handed your patient is now being sold in the alley behind your hospital. Perhaps your patient is getting multiple prescriptions for controlled substances from several doctors who don’t know about each other. Maybe you’ve just been handed a forged prescription.
Those situations are examples of pharmaceutical diversion, which the Drug Enforcement Admin istration says accounts for as much as 30% of the drug problem in the United States. It took a while for law enforcement, doctors, and pharmacists to recognize the problem; after all, doctors prescribe medications and pharmacists dispense them properly and warn patients about side effects and contraindications. Everything goes through the correct channels, so how could abuse occur?
Experts say Xanax, Valium, and Librium are among the most abused drugs, as are opioids like morphine and codeine. In some parts of the country, the muscle relaxant Soma is abused because of the way it reacts with alcohol. On the street, some drugs can fetch a price as high as $60 a pill.
There is a difference between abuse and addiction, says Sidney Schnoll, MD, PhD, staff director at the Medical College of Virginia at Virginia Commonwealth University in Richmond. Addic tion occurs when people take more pills than they wanted to when they started, their ability to function decreases, and they have cravings and spend time thinking about how to get the drug, he says. "If you have all those characteristics, plus physical symptoms, you are addicted."
There’s also a difference between addiction and dependency. Dependency is purely physiological. It’s why patients have to taper off some medications rather than stopping cold turkey.
Watching for prescription abuse
Addiction is a disease, marked by the continued use of a drug despite its growing negative effects, says Susan Winckler, RPh, group director of policy and advocacy at the American Pharmaceutical Association (APhA). "Part of the pharmacist’s role in ensuring the proper use of medications is to guard against facilitating an addiction by continuing to provide the drug," she says.
Schnoll says it is difficult to gauge the scope of the problem; that is, to know what percentage of patients prescribed a given medication actually develop problems. Available data suggest the percentage is fairly small. Moreover, those who are identified as abusers or addicts are likely those with the most severe problems. They get caught forging prescriptions, stealing drugs, or selling them on the streets. Sometimes their physicians catch them. But those who have milder problems may never be identified by the system.
To uncover more information about prescription drug abuse, Schnoll says, more post-market studies are needed, but pharmaceutical companies are hesitant to conduct them because of the expense. One possible solution may be to establish "Phase IV centers," which would be funded by corporations and the government, so no one entity would have to bear the entire cost.
Schnoll outlines another complication as well, something he calls "pseudo-addiction." "Doctors sometimes worry about prescribing some medications, so they underprescribe what patients need. So the patient requests more medication, and the doctor may identify them as an addict. But once they get the correct level of medication, the patient no longer indicates drug-seeking behavior."
Winckler agrees: "Because there is so much regulatory oversight of controlled substances, physicians and pharmacists are skittish about these prescriptions. Underuse is as much of a problem as overuse. Pharmacists have been put in a difficult situation where they must sometimes act as cops. So they have to remember, OK, there is under-treatment of pain, and not assume right off that the patient is an addict."
Because the situation is so complex, communication between physician and pharmacist is crucial. The pharmacist should watch out for patients who have prescriptions for controlled substances from several different doctors, or those who come in for early refills. Also, addicted patients may jump around to different pharmacies.
In Arkansas, there is an alert system in place, a rapid communication system pharmacists can use to warn each other about patients with drug problems and forged prescriptions. The system has been in place since the 1980s, says Jan K. Hastings, MD, associate professor at the University of Arkan sas Medical Sciences College of Pharmacy. She says using the system is one option for pharmacists; otherwise, it’s a matter of relying on intuition and experience to decide what to do.
"In my case, I do confront the patient," she says. "I use open-ended questions to get the patients to tell me as much as they can without making them feel threatened. The goal is not to punish them but to help them get treatment. Also, I personally let all the doctors know if the patient is seeing multiple doctors. I ask if they know about each other and if they still want me to fill the prescription."
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