Tiagabine
Tiagabine (trade name Gabitril) is an anticonvulsant medication produced by Cephalon that is used in the treatment of epilepsy. The drug is also used off-label in the treatment of anxiety disorders and panic disorder. Tiagabine is approved by U.S. Food and Drug Administration (FDA) as an adjunctive treatment for partial seizures in individuals of age 12 and up. It may also be prescribed off-label by physicians to treat anxiety disorders and panic disorder as well as neuropathic pain (including fibromyalgia). For anxiety and neuropathic pain, tiagabine is used primarily to augment other treatments. Tiagabine may be used alongside selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, or benzodiazepines for anxiety, or antidepressants, gabapentin, other anticonvulsants, or opioids for neuropathic pain. It is effective as monotherapy and combination therapy with other antiepileptic drugs in the treatment of partial seizure. The American Academy of Sleep Medicine's 2017 clinical practice guidelines recommended against the use of tiagabine in the treatment of insomnia due to poor effectiveness and very low quality of evidence. Side effects of tiagabine are dose related. The most common side effect of tiagabine is dizziness. Other side effects that have been observed with a rate of statistical significance relative to placebo include asthenia, somnolence, nervousness, memory impairment, tremor, headache, diarrhea, and depression. Adverse effects such as confusion, aphasia (difficulty speaking clearly)/stuttering, and paresthesia (a tingling sensation in the body's extremities, particularly the hands and fingers) may occur at higher dosages of the drug (e.g., over 8 mg/day). Tiagabine may induce seizures in those without epilepsy, particularly if they are taking another drug which lowers the seizure threshold. There may be an increased risk of psychosis with tiagabine treatment, although data is mixed and inconclusive. Tiagabine can also reportedly interfere with visual color perception.
