From the Guidelines
Gabapentin is consistently associated with weight gain, affecting approximately 10-15% of patients who take the medication. The weight gain typically ranges from 5-15 pounds, though some patients may experience more significant increases. This side effect tends to develop gradually over the first few months of treatment and may continue throughout therapy. The mechanism behind gabapentin-associated weight gain is not fully understood but likely involves increased appetite, fluid retention, and decreased metabolic rate, as suggested by 1. Patients with certain risk factors, including pre-existing obesity, sedentary lifestyle, or concurrent use of other medications that cause weight gain, may be more susceptible.
To manage this side effect, patients can:
- Monitor their weight regularly
- Maintain a balanced diet
- Engage in regular physical activity
- Discuss concerns with their healthcare provider. If weight gain becomes problematic, dose adjustments or alternative medications might be considered, though patients should never discontinue gabapentin without medical supervision due to the risk of withdrawal symptoms, as noted in 1. It is essential to prioritize the patient's overall health and well-being, considering the potential impact of weight gain on morbidity, mortality, and quality of life.
From the FDA Drug Label
Table 3 lists adverse reactions that occurred in at least 1% of gabapentin-treated patients with postherpetic neuralgia participating in placebo-controlled trials and that were numerically more frequent in the gabapentin group than in the placebo group. ... Metabolic and Nutritional Disorders Peripheral edema 8 2 Weight gain 2 0 ... TABLE 4 Adverse Reactions in Pooled Placebo-Controlled Add-On Trials In Epilepsy Patients >12 years of age ... Body As A Whole Fatigue 11 5 Weight Increase 3 2 ...
Weight Gain Percentage:
- In postherpetic neuralgia patients, 2% of gabapentin-treated patients experienced weight gain, compared to 0% of placebo-treated patients 2.
- In epilepsy patients >12 years of age, 3% of gabapentin-treated patients experienced weight increase, compared to 2% of placebo-treated patients 2.
From the Research
Weight Gain with Gabapentin
- The study 3 found that out of 44 patients treated with gabapentin, 10 patients gained more than 10% of their baseline weight, and 15 patients gained 5% to 10% of their baseline weight.
- This translates to approximately 57% of patients (25 out of 44) experiencing some degree of weight gain.
- The weight gain occurred in patients taking gabapentin in combination with other antiepileptic drugs, as well as in those taking gabapentin as monotherapy.
- The study 4 also found that long-term treatment with gabapentin was associated with little weight gain, with a mean weight change of +0.76 kg over 24 weeks.
Comparison to Other Studies
- The study 5 examined weight change patterns in patients treated with pregabalin, a medication similar to gabapentin, and found that approximately 16% of patients experienced significant weight gain.
- The study 6 noted that gabapentin is not typically associated with significant weight gain, unlike some other antiepileptic drugs such as sodium valproate and pregabalin.
- The study 7 planned to examine the risk of heart failure and edema associated with pregabalin, but did not provide information on weight gain with gabapentin.