Lavigne, J.E., Heckler, C., Mathews, J.L., Palesh, O., Kirshner, J.J., Lord, R., . . . Mustian, K. (2012). A randomized, controlled, double-blinded clinical trial of gabapentin 300 versus 900 mg versus placebo for anxiety symptoms in breast cancer survivors. Breast Cancer Research and Treatment, 136, 479–486.

To compare the efficacy of gabapentin 300 mg and 900 mg for controlling anxiety symptoms among breast cancer survivors

Patients were randomly assigned to receive 300 mg or 900 mg of gabapentin or placebo daily. Outcomes were assessed at baseline, four weeks, and eight weeks.

• The study reported on a sample of 420 female patients with breast cancer.
• Mean patient age was 55 years.
• All patients had completed initial therapy.
• More than 75% of patients were married, and about 70% were on tamoxifen.
• All patients had at least two hot flashes per day for seven days prior to enrollment.

• Single site
• Outpatient setting
• Rochester Cancer Center

Patients were undergoing the transition phase of care after initial treatment.

A double-blind, placebo-controlled, randomized controlled trial design was used.

• Strait-Trait Anxiety Inventory
• MD Anderson Symptom Inventory

At four weeks, patients on gabapentin showed significant reduction in anxiety scores (p = 0.005). Patients with the highest baseline anxiety scores had the greatest improvement, and those with low anxiety levels had little change. These patterns were maintained at the eight-week follow-up. The greatest improvement in anxiety was seen in those getting 300 mg of gabapentin. Anxiety scores of those on placebo also declined, but changes were not significant.

 Gabapentin 300 mg daily was effective in reducing symptoms of anxiety in these breast cancer survivors.

• Findings are not generalizable.
• The sample was women who also had hot flash symptoms; the mechanism of action of gabapentin has been associated with mechanisms causing hot flashes, so this may not have the same effect in women who do not have hot flash symptoms.

This study demonstrated that 300 mg of gabapentin daily was effective in controlling anxiety symptoms among breast cancer survivors who had been experiencing hot flashes and had relatively high baseline anxiety. Gabapentin is currently off label in psychiatry to treat anxiety symptoms and commonly used to treat hot flashes and neuropathic pain in breast cancer survivors. As shown in other research, improvement in anxiety symptoms tends to be found in patients who have clinically relevant levels of anxiety to begin with. Nurses can consider and advocate for use of gabapentin to manage anxiety in these patients.