Sunday, July 13, 2008

No Pill for Stimulant Addiction

Meth and cocaine continue to elude researchers.

Despite promising trials of several compounds, methamphetamine addiction remains largely impervious to anti-craving pills and other forms of drug treatment. According to a paper in the June issue of Addiction Science and Clinical Practice, "currently, no medications are approved by the FDA for the treatment of stimulant dependence. However, recent advances in understanding... have allowed researchers to identify several promising candidates."

The paper's author, Dr. Kyle Kampman of the University of Pennsylvania School of Medicine and Treatment Research Center, notes that "the demand for treatment for cocaine dependence remained roughly level from 1992 to 2005, while the demand for treatment for amphetamine dependence increased about eight-fold." (See chart above).

As I wrote earlier ("FDA Puts Coke/Meth Treatment on Fast Track"), the U.S. Food and Drug Administration (FDA) in January gave Fast Track designation to vigabatrin, sold as Sabril by Ovation Pharmaceuticals. Ovation is collaborating with the NIDA on Phase II studies to evaluate the safety of Sabril, with Phase III trials scheduled for the end of this year.

Vigabatrin, an anti-epilepsy drug called Gamma-vinyl-GABA, or GVG for short, showed early promise for use with cocaine addicts in a 60-day study and appears to increase GABA transmission. GABA has an inhibitory effect on dopamine and serotonin release.

Another entry in the vigabatrin sweepstakes, Catalyst Pharmaceuticals, is also testing its version of the drug, dubbed CPP-109, for the treatment of methamphetamine addiction in Phase II double-blind, placebo-controlled studies. Patrick J. McEnany, chief executive officer of Catalyst, commented, "We are excited to follow up on our cocaine trial with the initiation of our second, large-scale U.S. Phase II trial with CPP-109, this time as a potential treatment for methamphetamine addiction. As with cocaine, we believe that CPP-109 may offer the potential to provide patients suffering from methamphetamine addiction, as well as the physicians and clinicians that treat them, with a safe and effective pharmacotherapy option."

What, in essence, are such pills designed to accomplish? The primary avenue of research has centered upon medications that decrease the addict's experience of withdrawal and craving. According to Kampan, "several studies have demonstrated that patients who experience severe cocaine withdrawal symptoms... are twice as likely to drop out of treatment and less likely to attain abstinence in outpatient programs."

However, questions remain about the safety of vigabatrin. Although available abroad, it is not approved for use in the U.S., due to an association with serious visual effects after long-term use. The use of vigabatrin for stimulant addiction, if approved, might require associated eye examinations.

Buproprion, a drug that has shown some promise in the treatment of cocaine addiction, is also a candidate for meth addiction. The drug inhibits the reuptake of dopamine, thus allowing more dopamine to circulate in the brain. In addition, there are plans to test other drugs being investigated for cocaine craving, such as topiramate and modafinil.

According to the 2005 SAMHSA Survey on Drug Use and Health, an estimated 10.4 million people age 12 or older (4.3 percent of the population) have tried methamphetamine at some time in their lives. Approximately 1.3 million reported past-year methamphetamine use, and 512,000 reported current (past-month) use. Approximately 535,000 patients sought treatment for methamphetamine and other stimulant abuse in 2006.

Next post: Drugs for cocaine craving

Photo Credit: National Drug Intelligence Center


kayakotto said...

I agree that stimulant and methamphetamine addiction is at all time highs and could easily be classified as being at epidemic levels. I am a firm advocate of the drug free approach to addiction treatment, getting the issues behind addiction out in the open, effectively dealing with them rather than covering them up with some other drug or medication.

Dirk Hanson said...

It's not clear to me how the use of an effective anti-craving medication during withdrawal can be seen as "covering up" the problem of addiction. Moreover, since "talk therapy" has utterly failed to make a dent in addiction numbers, perhaps it's time for a medical approach?

Anonymous said...

I can never understand why we keep having this argument about which approach is right. surley we should be embracing both 'talk theapy' and the medical approach to work together. I would argue that if both were used together properly and more often, success rates would increase.

Dirk Hanson said...

You are quite right, and studies seem to bear this out: The best approach is a combination of medical and cognitive therapies.

I emphasize the medical side, because kayakotto's attitude above is quite common, and we still have a long ways to go before the wisdom of pharmacological approaches to abstinence are more commonly accepted and understood. After all, it took years (and the battle continues) for people to get used to the idea that a pill, rather than meetings with a disciple of Freud, might work better on their clinical depression.

Peter O'Loughlin said...

Given that Freud at the behest of two seperate drug companies, both of whom are still thriving, wrote two seperate papers advocating and eulogising cocaine as a 'cure' for alcohol and morphine addiction, one is hard pressed to attach much credibility to his views.

On the other hand to suggest that 'talking therapies' has not had a favourable impact on drug addiction is grossly inaccurate as can be witnessed by the well documented evidence regarding the effectiveness of 12 step fellowships.

We need to acknowledge that addiction is an intractable, three dimensional condition, i.e. mental, physical and spiritual, for which science has yet to find a cure. As Carl Jung in an exhchange of correspondence with Bill 'W',the co-founder of AA pointed out, "science has no answer to this problem, psychotherapy alone is useless, what is required is a spiritual experience".

I would also point critics of 'talking therapies' to the peer reviewed highly aclaimed 'transtheoritcal model of Prochaska and Di Clemente, which has withstood considerable critcial examination, and is an invaluable framework within which the process of recovery can be achieved. It also has the added adavantage that each stage in the cycle fits elegantly with the underlying tried and tested principles contained within the 12 steps of recovery

Given that the majority of people start to use drugs in order to change the way they feel, thereby, bringing about an effortless, altered state of consciouness,in itself a 'spiritual experience', Jung's view makes as much good sense now as it did then.

Pharmacotherapy does have a valuable and in many cases, an indespensible role, to play in recovery; however we need to remember the World Health Organisation evidence which concludes that any drug which is effective in addressing addiction, does in itself, have a potential for addiction; methadone is just one example. Long term use of it as is the case here in the UK, is not just a question of swapping one addiction for another, but acquiring a secondary addiction.

We should also aknowledge that many of those on MMT continue to misuse other drugs, thereby escalating their problems. Further notwithstanding claims by the pharmaceutical companies, the latest drugs being pushed for opiate and alcohol dependence, also have an addictive potential.

Perhaps we should tread a little more carefully in being too enthusiastic about 'silver bullets' and pay heed to the urgings of Hippocrates to ' "first do no harm"

Dirk Hanson said...

Thanks for the thoughtful response.

I admit that I was not thinking of AA and 12-Step procedures when I referred to "talk therapies." I had in mind formal psychotherapy, which has not been very useful in curing addictions, in and of itself.

It's a shame that methadone is the early example that tends to typify people's reaction to anti-craving drugs. Any such drug which is itself addictive is a problem--but the majority of compounds being tested today are not addictive drugs.

Carl Jung may have disparaged science as useful in addiction, but Bill W. disagreed. He believed in spiritual conversion, but he also was enthused about early scientific experiments using LSD to cure alcoholics.

First do no harm--hard to beat as a first principle. But the edges are fuzzy. If we do nothing for addicts, we do them serious harm. If we offer them safe but ineffective treatments, we also do them harm.

Most researchers, I think, are well past the "magic bullet" stage, and realize that nothing about pharmacological approaches to addiction treatment is going to be easy.

Thanks again for your thoughtful post.

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