Active substances: Gabapentin
Gabapentin is a GABA analogue used in the treatment of epilepsy, neurogenic pain, restless-leg syndrome, essential tremor, bipolar disorder, and migraine prophylaxis; it was first reported for its effects on hot flashes in five women and one man.
The most commonly used dose of gabapentin is 900 mg per day. However, we decided to study a lower dose 300 mg per day also; if this dose could control hot flashes, the patients would benefit overall.
The 8-week study duration was selected on the basis of our previous study of clonidine, 15 to provide internal consistency.
Methods Patients The patients were participants in a multicentre clinical trial at 18 geographically diverse member sites of the University of Rochester Community Clinical Oncology Program. Women aged 18 years or older who had breast cancer and were having an average of two or more hot flashes per day were eligible to take part in the study.
Acceptable non-steroidal contraceptive measures were required. Patients currently receiving chemotherapy were not eligible, although endocrine therapies were allowed.
Most of the patients were taking adjuvant tamoxifen. Patients taking venlafaxine, clonidine, or anticonvulsants were not eligible for the study, but use of other antidepressants including selective serotonin-reuptake inhibitors and serotonin and norepinephrine reuptake inhibitors was allowed.
The other reasons for exclusion were: pregnancy; breastfeeding; use of steroidal contraception; coronary insufficiency; recent history of myocardial infarction, symptomatic cardiac disease, peripheral or cerebrovascular disease, stroke, syncope, or symptomatic hypotension; hepatic dysfunction aspartate aminotransferase concentration above twice the upper limit of normal, or bilirubin concentration above the upper limit of normal, as defined at each institution; renal dysfunction serum creatinine concentration above 1.
The Institutional Review Boards of the University of Rochester and each participating site approved the protocol.
Written informed consent was obtained from each participant. Design and procedures Patients were randomly assigned placebo, gabapentin 100 mg, or gabapentin 300 mg, each to be taken by mouth three times a day, for 8 weeks.
There was a 3-day titration period for all patients because the study was double-blind.
The study drugs were supplied as capsules of similar appearance in bottles. Check your medicine each time you get a refill to make sure you receive the correct form. Important information Some people have thoughts about suicide while taking this medicine.
Stay alert to changes in your mood or symptoms. Report any new or worsening symptoms to your doctor.
Do not stop using Neurontin suddenly, even if you feel fine. Before taking this medicine You should not use Neurontin if you are allergic to gabapentin.
To make sure Neurontin is safe for you, tell your doctor if you have ever had: lung disease, such as chronic obstructive pulmonary disease COPD; kidney disease or if you are on dialysis; diabetes; depression, a mood disorder, or suicidal thoughts or actions; a seizure unless you take gabapentin to treat seizures; liver disease; heart disease; or for patients with RLS if you are a day sleeper or work a night shift.
Some people have thoughts about suicide while taking this medicine.Louis Park, MN Correspondence and reprints requests to: Charles L.
Your doctor should check your progress at regular visits. Your family or other caregivers should also be alert to changes in your mood or symptoms.