Gabapentin is quite popular with physicians for numerous off-label uses. It is considered to be relatively safe to administer (has few side effects and few dangerous interactions with other drugs). Because it mimics the actions of the inhibitory neurotransmitter GABA, it can be used in many situations where other medicines that could potentially have serious side effects might present a potential issue; for example, benzodiazepines might not the best course of action due to their highly addictive nature.
Gabapentin is frequently used in the treatment of anxiety disorders. However, there are no randomized controlled trials on the effectiveness of this medication in generalized anxiety disorder (GAD), and there are only a few case reports. We present a case of a 59-year-old female with a psychiatric history of GAD.
The patient discontinued benzodiazepines after more than 7 years of daily treatment which led to rebound anxiety, benzodiazepine withdrawal symptoms, and suicidal ideation. She was psychiatrically hospitalized and started on gabapentin. Over the next 10 months of outpatient follow-up, she attempted to taper off gabapentin due to personal preference to limit medications. During this time, we observed a clear dose-response pattern of gabapentin on GAD symptoms.
In the absence of controlled studies, these findings may offer important information about the effectiveness of gabapentin in GAD.
While gabapentin is increasingly being used to treat generalized anxiety disorder (GAD), little is known about its effectiveness on GAD symptoms. The patient presented here has a relatively straightforward psychiatric history, with GAD playing a prominent role.
Her repeated attempts to discontinue gabapentin offer a rare opportunity to observe its effect on her symptoms at different doses. A clear pattern of remission or mild anxiety on total daily doses of gabapentin ≥ 900 mg/day and severe anxiety at doses < 600 mg/day was observed.
In the absence of randomized controlled trials, these findings may offer clinically important clues about dosing and effectiveness of gabapentin in GAD.
Several follow-up research studies included one study that looked at gabapentin’s utility in treating social phobia and panic disorder. Gabapentin performed better than a placebo, but worse than standard treatments for social phobia. It was not more efficacious than placebo for panic disorder symptoms, except for very severe symptoms. It was not as effective for panic disorder compared to standard treatments (benzodiazepines and/or selective serotonin reuptake inhibitors).
However, if the drug is not as effective in treating anxiety disorders as standard treatments, these benefits have little clinical utility.
In cases where gabapentin demonstrated some effect in treating anxiety, the effects of gabapentin apparently take a week or more to present, if it results in any anxiety reduction at all. In some cases, the effects may not be apparent until a month after the person is taking gabapentin. Doses used in these studies were relatively high (up to 3600 mg per day).
Research continues to investigate its effectiveness in the treatment of anxiety, and as mentioned in the above initial studies, it appears that gabapentin is not as effective as standard treatments for anxiety disorders. Gabapentin may have more utility as an adjunctive medication to assist standard treatments or to treat the lower-level anxiety that occurs in other types of disorders than it does as a standalone treatment for addressing the severe anxiety that occurs in anxiety disorders.
