Gabapentin for Hot Flashes

Efficacy Profile

Gabapentin at 900 mg/day reduces hot flash frequency by approximately 45-51% and severity scores by 46-54%, with rapid onset of action within one week, according to the American Society of Clinical Oncology 1, 2
The reduction in hot flash frequency is 45-51% versus 26-31% with placebo, and the reduction in hot flash severity scores is 46-54% versus 31% with placebo 1
Gabapentin is effective across multiple populations, including breast cancer patients, women with chemically/surgically induced menopause, and spontaneous menopause, with reductions of 49%, 54%, and 51%, respectively 1, 2
Significant improvement is seen within the first week of treatment, with sustained efficacy for up to 12 weeks 1, 3

The American College of Obstetricians and Gynecologists recommends starting gabapentin at 300 mg/day and titrating to 900 mg/day over 1-3 weeks for optimal efficacy, with assessment of response at 4 weeks 1, 3, 2

Gabapentin offers several clinical advantages, including no drug interactions, particularly important for patients on tamoxifen, unlike SSRIs which inhibit CYP2D6 and reduce tamoxifen efficacy, according to the National Comprehensive Cancer Network 1, 2
Gabapentin has no sexual dysfunction as a side effect, unlike SSRIs/SNRIs, and no withdrawal syndrome, unlike paroxetine and venlafaxine, as stated by the American College of Clinical Pharmacology 1, 4
Gabapentin has no absolute contraindications and provides additional benefit for neuropathic pain if present concurrently, as recommended by the American Academy of Neurology 1, 4, 3

Side effects occur in up to 20% of patients but are typically transient, improving markedly after the first week and largely resolving by week 4, with common side effects including dizziness, unsteadiness, and drowsiness, according to the American Society of Clinical Oncology 1, 4, 3
Discontinuation rates due to side effects are approximately 10% in clinical trials, lower than clonidine and comparable to SSRIs/SNRIs, as reported by the National Institutes of Health 3

The American College of Clinical Pharmacology recommends using gabapentin as first-line therapy in patients on tamoxifen, patients with sexual dysfunction concerns, patients who failed or cannot tolerate SSRIs/SNRIs, and patients with concurrent neuropathic pain, due to its superior efficacy and tolerability profile 1, 2, 3

Gabapentin shows superior efficacy to both clonidine and most SSRIs/SNRIs, with a mean reduction in daily hot flashes versus placebo of -2.05, compared to -1.13 for SSRIs/SNRIs and -0.95 for clonidine, as stated by the American Society of Clinical Oncology 3
Gabapentin has better tolerability than clonidine, with a 10% discontinuation rate compared to 40% for clonidine, and faster resolution of side effects compared to SSRIs/SNRIs, according to the National Comprehensive Cancer Network 3, 1

For breast cancer patients on tamoxifen, gabapentin is particularly advantageous, with a 49% reduction in hot flashes without drug interactions, as recommended by the American Society of Clinical Oncology 1, 2