June 19, 2009

Researchers Find Potential Replacement For Common Anxiety Drugs

In Germany, a group of researchers believe they may have discovered a more sophisticated anti-anxiety drug capable of controlling panic attacks without the hefty side effects associated with most currently available treatments.

Diazepam, the active ingredient in the popular drug Valium, has been used for more than 40 years to treat acute anxiety symptoms.  Though highly effective in helping patients manage panic attacks, Valium is frequently accompanied by a number of unpleasant side effects including drowsiness, forgetfulness and clumsiness.  Moreover, patients taking the drug for extended periods of time have demonstrated a high incidence of developing dependency.

According the team of German scientists in Munich however, the new chemical compound "” known for the time being as XBD173 "” seems able to circumvent these side effects by utilizing a different biochemical pathway to switch off the brain's panic response.

Details from the Phase I clinical trials of the breakthrough study were published in Thursday's edition of the renowned journal Science. 

Swiss-based multinational pharmaceutical giant Novartis has provided funding for the project since its inception.  A representative for the company said that clinical development of the new drug has now been handed off to its Japanese partner Dainippon Sumitomo Pharma.

"What is needed right now is a rapid-acting anxiolytic (anxiety drug) that is effective but lacks the side effects of benzodiazepines," said Rainer Rupprecht, the German team's lead researcher at the Ludwig Maximilian University in Munich.

Rupprecht added that his group's work shows promising potential that the development of just such a drug may not be too far away.

In addition to benzodiazepine-derived drugs like Valium, another class of drugs commonly known as SSRI's (or selective serotonin reuptake inhibitors) have become a popular alternative for treating anxiety disorders in recent years.  Drugs such as Prozac have been used with some success for moderating long-term anxiety symptoms but are little avail for patients suffering from sudden, acute panic attacks as the drugs take several weeks to start working. 

In the initial phases of research performed on rats, the new XBD173 was shown to take effect within one hour.

Lab tests involved injecting test subjects with a chemical known as CCK-4 which induces a brief anxiety attack, after which they were given XBD173.  Researchers observed a rapid physiological calming response to the drug with no apparent side effects or withdrawal symptoms.

Like Valium, the new drug works by interacting with an inhibitory neurotransmitter in the brain known as GABA.  The XBD173 compound however operates indirectly by promoting the synthesis of neurosteroids that modify the effects of GABA.

Pharmaceutical companies have struggled for years"”largely in vain"”to find an effective replacement for benzodiazepines with fewer side effects. 

In the 1980's benzodiazepines were responsible for Britain's largest ever class action lawsuit against drug manufacturers, involving some 14,000 patients and 1,800 law firms alleging that the pharmaceutical companies knew of the drug's potential to cause dependence but intentionally withheld this information from doctors.


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