A ligand, or binding molecule, of the translocator protein (18 kDa) seems to quickly counteract anxiety and panic attacks in mice as well as humans—and without the negative side effects associated with other current remedies, researchers say. This finding suggests that this ligand, XBD173, might be a good candidate for use as a safe and fast-acting anti-anxiety agent.
Anxiety disorders are highly prevalent and can be very disabling, frequently turning into chronic clinical conditions. Current treatments like benzodiazepines often have unwanted side effects like sedation, tolerance, or symptoms of withdrawal after chronic use. Anti-depressant drugs are also sometimes administered to treat anxiety, but their beneficial effects only occur after several weeks of treatment.
The new research suggesting a naturally occurring ligand as a candidate for a fast and effective anti-anxiety agent is published in the 19 June 2009 issue of the journal Science.
Dr. Rainer Rupprecht, M.D., from Ludwig Maximilian University and the Max Planck Institute of Psychiatry, along with colleagues from various institutes and universities across Germany and Switzerland, performed a series of experiments with rats and human subjects.
Looking for something new to counteract anxiety, Rainer Rupprecht and colleagues administered XBD173 to laboratory rats and observed that it prevented panic behavior almost immediately—without the rats building tolerance or any other unwanted side effects.
They then performed a study among 70 healthy human men, involving a placebo group, and found that XBD173 initiated a fast anti-anxiety response without any withdrawal symptoms after prolonged use.
"The number of side effects reported with XBD173 was comparable to the incidence in the placebo group," Rupprecht writes in his report. "No serious adverse event occurred during the entire study and there was no need for treatment of withdrawal symptoms... Thus, ligands of the translocator protein (18 kDa) such as XBD173 may represent a pharmacological mechanism to treat anxiety disorders."
These researchers say that XBD173 promotes these calming effects through its modulation of the inhibitory neurotransmitter, GABA, and they recommend the ligand be considered for use in future clinical applications.