Failure to recruit due to polypharmacy

We will attempt to establish whether gabapentin as compared with placebo will reduce the severity of tremors caused by the use of antipsychotic medications. Baseline severity of tremor will be measured using both clinical ratings and ratings obtained with an instrument designed to measure tremor, giving more objective evidence of tremor frequency and severity.

We propose to enroll 40 veterans with antipsychotic induced tremor in this RCT of gabapentin. Baseline measurements will be obtained with the tremor section of the UPDRS, the Simpson-Angus Scale, the ESRS, AIMS, and the Barnes Akathisia SScale. The Tremorometer, an instrument designed to quantatatively measure frequency, amplitude, and tremor power will be used for baseline and subsequent assessments. Demographic data will be collected. Diagnoses will be established with the SCID. Appropriate lab studies with an EKG will be done at baseline and at study end. Patients will be randomized to gabapentin or placebo and assessed on a blinded basis. Effectiveness of the blind will be assessed at study end. Gabapentin will be started at 300 mg/day and tapered up to a maximum of 1800 mg/day. The SF36 will be used to assess quality of life.

Inclusion Criteria:

• Veterans 18 and older with an observable tremor judged to be caused by exposure to antipsychotics

Exclusion Criteria:

• Concomitant use of other anticonvulsants, L-Dopa, cocaine, amphetamines, or other tremorogenic agents excepting SSRIs, TCAs.
• Current suicidality, severe psychosis, inability to sign informed consent or to cooperate with study procedures.
• Current use of gabapentin or exposure to gabapentin in the past 2 years.
• Women who are pregnant, or not using adequate birth control.