Can gabapentin (Gabapentin) be used to manage hot flashes?

Gabapentin for Hot Flashes

Gabapentin at 900 mg/day is an effective first-line treatment for moderate to severe hot flashes, reducing hot flash frequency by approximately 45-51% and severity scores by 46-54%, with rapid onset of action within one week. 1

Efficacy Profile

Gabapentin demonstrates superior efficacy compared to placebo and is the only nonhormonal treatment shown to have equivalent efficacy to estrogen therapy for hot flashes. 1 The evidence shows:

• Reduction in hot flash frequency: 45-51% versus 26-31% with placebo 1, 2
• Reduction in hot flash severity scores: 46-54% versus 31% with placebo 1, 2
• Effective across multiple populations: breast cancer patients (49% reduction), women with chemically/surgically induced menopause (54% reduction), and spontaneous menopause (51% reduction) 1
• Rapid onset: Significant improvement within the first week of treatment 1
• Sustained efficacy: Maintains effectiveness for up to 12 weeks 1, 3

Dosing Algorithm

Start gabapentin at 300 mg/day and titrate to 900 mg/day over 1-3 weeks for optimal efficacy. 1, 4

• Week 1: 300 mg/day (divided doses)
• Week 2: 600 mg/day (divided doses)
• Week 3 onward: 900 mg/day (divided in three doses) 5, 4
• The 300 mg/day dose is NOT effective - only the 900 mg/day dose shows significant benefit over placebo 4
• Assess response at 4 weeks: If no improvement by 4 weeks, treatment is unlikely to be effective and should be discontinued 1

Key Advantages Over Alternatives

Gabapentin offers several clinical advantages that make it particularly suitable for certain patient populations: 1

• No drug interactions - particularly important for patients on tamoxifen, unlike SSRIs (paroxetine, fluoxetine) which inhibit CYP2D6 and reduce tamoxifen efficacy 1
• No sexual dysfunction - unlike SSRIs/SNRIs which commonly cause this side effect 1
• No withdrawal syndrome - unlike paroxetine and venlafaxine 1
• No absolute contraindications 1
• Additional benefit for neuropathic pain if present concurrently 1

Side Effect Profile and Tolerability

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. 1

Common side effects include: 1

• Dizziness
• Unsteadiness
• Drowsiness

Discontinuation rates due to side effects are approximately 10% in clinical trials - lower than clonidine (40%) and comparable to SSRIs/SNRIs (10-20%). 1, 5

Clinical Decision-Making

Use gabapentin as first-line therapy in the following scenarios: 1

1. Patients on tamoxifen - gabapentin has no drug interactions, whereas paroxetine and fluoxetine should be avoided 1
2. Patients with sexual dysfunction concerns - either pre-existing or as a side effect from SSRIs/SNRIs 1
3. Patients who failed or cannot tolerate SSRIs/SNRIs 1
4. Patients with concurrent neuropathic pain - dual benefit 1
5. As an alternative first-line option alongside SSRIs/SNRIs for moderate to severe hot flashes 1

Important caveat: There is no benefit to adding gabapentin to SSRIs/SNRIs - use one or the other, not both. 1

Comparison to Other Nonhormonal Options

Gabapentin shows superior efficacy to both clonidine and most SSRIs/SNRIs: 1

• Mean reduction in daily hot flashes versus placebo: Gabapentin -2.05, SSRIs/SNRIs -1.13, Clonidine -0.95 1
• Better tolerability than clonidine (10% vs 40% discontinuation rate) 1
• Faster resolution of side effects compared to SSRIs/SNRIs 1

Special Populations

For breast cancer patients on tamoxifen: Gabapentin is particularly advantageous as the majority of studied breast cancer patients were taking tamoxifen and still achieved 49% reduction in hot flashes without drug interactions. 1

For men with prostate cancer on androgen deprivation therapy: Gabapentin 900 mg/day shows moderate efficacy with minimal adverse effects for at least 12 weeks. 3