The use of adjunct gabapentin in the treatment of anxiety-related disorders also has been recently reported. One study evaluated the use of gabapentin in 18 patients who were diagnosed with schizophrenia, schizoaffective disorder, bipolar illness, and generalized anxiety. These patients also had comorbid illnesses, including panic disorder, alcohol dependence, obsessive-compulsiveness, generalized anxiety, drug dependency, and major depression. In 14 of them, gabapentin 200-1800 mg/day (range 100-4400 mg/day) resulted in an undefined positive response in anxiety-related symptoms (insomnia, somatic complaints, generalized anxiety, psychotic anxiety, obsessive-compulsive symptoms). Nine patients discontinued therapy, with the most common side effects being dizziness and drowsiness.
Another study reported the adjunct use of gabapentin in three patients. One patient had a history of panic disorder with limited phobic avoidance, recurrent major depression, past alcohol abuse, and marked irritability. Gabapentin 100 mg 3 times/day was titrated to 1200 mg/day and finally reduced to 400 mg twice/day due to sedation. The patient experienced reductions in panic frequency, irritability, and depressive symptoms that were sustained at 6-month follow-up. A second patient had a history of generalized anxiety disorder and intermittent checking rituals that did not meet criteria for obsessive-compulsive disorder (OCD). Gabapentin 100 mg 3 times/day led to improvement in symptoms of worry that was sustained at 3-month follow-up. No change was noted in checking rituals. The third patient had attention-deficit hyperactivity disorder (ADHD), generalized anxiety, and major depressive disorder, recurrent type. Gabapentin was titrated to 100 mg twice/day. Improvement in anxiety and decreased use of alcohol to self-medicate were reported and continued at 3-month follow-up.
Gabapentin monotherapy was begun in a patient with a 20-year history of panic disorder and alcohol dependence. After failing several therapeutic trials of various drugs, gabapentin 100 mg/day was begun and titrated to 300 mg 3 times/day over 2 weeks. The patient was reported to be panic free at week 5 and at 4-month follow-up.
In contrast, rebound anxiety-related symptoms (anxiety, depression, decreased sleep) developed in five patients with OCD after beginning adjunctive gabapentin therapy. All five patients reported the symptoms to be more severe than before the drug was added to their regimen. Gabapentin was restarted in four of the patients with resolution of the symptoms within a week.
The above information thankfully comes from the medscape.com at the following link.
