Pfizer
Diabetic neuropathic pain, post-herpetic neuralgia, and adjunctive treatment of epilepsy.
Approved for generalized anxiety disorder (GAD) in Europe as of March 2006.
Enhances presynaptic release of GABA; close chemical cousin of Neurontin (gabapentin).
Supplied in 25 mg, 50 mg, 75 mg, 100 mg, 150 mg, 200 mg, 225 mg, and 300 mg capsules.
Dosing recommendations based on controlled trials for GAD: Start at around 100 mg BID and increase as tolerated to a maximum of 300 mg BID.
No dose adjustment required in liver impairment. Reduce dose in patients with renal impairment and in elderly with some degree of renal impairment.
High rates of dizziness (about 30%) and sedation (22%).
Other common side effects: blurred vision, weight gain of about 5 pounds, peripheral edema, and impaired concentration/attention.
Has some limited abuse liability and is a Schedule V controlled substance (in the same category as cough suppressants containing codeine). Can cause a withdrawal syndrome of nausea, insomnia and headache if not gradually tapered.
No drug-drug interactions.
Not metabolized by the liver, is excreted unchanged by the kidney.
Half-life 6 hours.