Finding biological 'don't panic button' points to better anxiety drug
Last Updated: Thursday, June 18, 2009 | 6:21 PM ET
CBC News
A compound that counteracts anxiety in mice and humans may treat panic attacks without the side-effects of existing drugs like Valium, a new German study suggests.
Current treatments such as the benzodiazepine Valium, known generically as diazepam, often carry unwanted side-effects such as drowsiness and symptoms of withdrawal after chronic use.
Writing in Thursday's online issue of the journal Science, Rainer Rupprecht of Ludwig Maximilian University in Munich and his colleagues said the new compound, XBD173, immediately targetted a different "don't panic" button in lab rats without causing the animals to build up tolerance or any other side-effects.
No withdrawal symptoms
Initial tests among 70 healthy men who were either given XBD173, an older benzodiazepine, or a placebo showed the compound initiated a fast anti-anxiety response without any withdrawal symptoms.
The subjects were injected with a chemical CCK-4, which triggers a short-lived anxiety attack and raises heart rate and blood pressure.
The researchers said the test compound promotes calming by modulating the effects of a neurotransmitter called GABA.
Benzodiazepines also affect GABA, but in a different way.
Antidepressants known as selective serotonin reuptake inhibitors are also prescribed for anxiety disorders, but since they take several weeks to take effect, they are of no value for acute panic attacks.
Previous attempts by drug companies to create benzodiazepines with fewer side-effects haven't panned out.
