Amenorrhea in a patient after treatment with gabapentin for complex regional pain syndrome type II.

A 35-year-old woman suffered a traumatic injury to her right sciatic nerve requiring nerve exploration and external neurolysis. Following the surgery, the patient developed complex regional pain syndrome (CRPS) type II and was treated with gabapentin for pain control. Three months after the initiation of gabapentin therapy (1800 mg/day), the patient reported complete cessation of her menses. Based on hormonal tests, her gynecologist concluded that her amenorrhea was secondary to gabapentin therapy. The patient was weaned off the gabapentin over 6 days with return of her menses 2 weeks later. I conclude that gabapentin has the potential to cause amenorrhea with return of menses occurring after discontinuation of the drug.