Gabapentin is used for the treatment of
hot flashes and
neuropathic pain in
breast cancer survivors, and is commonly used off-label for the treatment of anxiety. Yet, clinical trial evidence to support the use of
gabapentin for anxiety symptoms is lacking. In a randomized, double-blinded controlled trial we compared 300 mg
gabapentin versus 900 mg
gabapentin versus placebo. Subjects were 420
breast cancer patients who had completed all
chemotherapy cycles. Anxiety traits and current (state) anxiety were measured using the Speilberger Strait-Trait Anxiety Inventory at baseline, 4 and 8 weeks.
Pain was measured at baseline using a 10-point scale. Analyses included analysis of covariance and ordinary least squares regression. At 4 weeks, state anxiety change scores were significantly better for
gabapentin 300 and 900 mg (p = 0.005) compared to placebo. The magnitude of improvement was proportional to baseline state anxiety. At 8 weeks, the
anxiolytic effects of
gabapentin compared to placebo persisted (p < 0.005). We found no significant interactions. The lower dose (300 mg) was associated with the best treatment outcomes for all patients except those with the highest baseline anxiety. Given its similar pharmacology, efficacy in the treatment of
hot flashes, and low cost,
gabapentin may provide a low cost and parsimonious alternative treatment choice for
breast cancer survivors presenting in primary care practices with anxiety symptoms.
Gabapentin is effective for
hot flashes, and, therefore, may provide therapeutic benefit for both anxiety and
hot flashes at a
generic drug price. For patients reluctant to take a
controlled substance, such as a
benzodiazepine,
gabapentin may offer an alternative
therapy. Similarly, patients with a history of
substance use may benefit from
gabapentin without risk of addiction or abuse. For cancer survivors experiencing both
hot flashes and anxiety,
gabapentin may provide a single effective treatment for both and is an alternative
therapy for anxiety for patients unwilling to take a
benzodiazepine or those with a history of
substance use.