brands

Class

• Anticonvulsant; selective GABA reuptake inhibitor (SGRI)

Gabitril commonly prescribed for

(Bold for FDA approved)

How Gabitril works

• Selectively blocks reuptake of gamma-aminobutyric acid (GABA) by presynaptic and glial GABA transporters

How long until Gabitril works

• Should reduce seizures by 2 weeks

• Not clear that it works in anxiety disorders or chronic pain but some patients may respond, and if they do, therapeutic actions can be seen by 2 weeks

Notable Side Effects

• Sedation, dizziness, asthenia, nervousness, difficulty concentrating, speech/language problems, confusion, tremor

• Diarrhea, vomiting, nausea

• Ecchymosis, depression

Life Threatening Side Effects

• Exacerbation of EEG abnormalities in epilepsy

• Status epilepticus in epilepsy (unknown if associated with tiagabine use)

• Sudden unexplained deaths have occurred in epilepsy (unknown if related to tiagabine use)

• New onset seizures and status epilepticus have been reported in patients without epilepsy

• Rare activation of suicidal ideation and behavior (suicidality)

weight gain

unusual

sedation

common

What to do about Gabitril side effects

• Wait

• Wait

• Wait

• Take more of the dose at night or all of the dose at night to reduce daytime sedation

• Lower the dose

• Switch to another agent

usual dosage range

• 32–56 mg/day in 2–4 divided doses for adjunctive treatment of epilepsy

• 2–12 mg/day for adjunctive treatment of chronic pain and anxiety disorders

Dosage Forms

• Tablet 2 mg, 4 mg, 12 mg, 16 mg, 20 mg

long term use

• Safe

habit forming

• No

Renal Impairment

• Although tiagabine is renally excreted, the pharmacokinetics of tiagabine in healthy patients and in those with impaired renal function are similar and no dose adjustment is recommended

Hepatic Impairment

• Clearance is decreased

• May require lower dose

Cardiac Impairment

• No dose adjustment recommended

Elderly

• Some patients may tolerate lower doses better

Children and Adolescents

• Safety and efficacy not established in children under age 12

• Maximum recommended dose generally 32 mg/day in 2–4 divided doses

Pregnancy

• Effective June 30, 2015, the FDA requires changes to the content and format of pregnancy and lactation information in prescription drug labels, including the elimination of the pregnancy letter categories; the Pregnancy and Lactation Labeling Rule (PLLR or final rule) applies only to prescription drugs and will be phased in gradually for drugs approved on or after June 30, 2001

• Controlled studies have not been conducted in pregnant women

• Use in women of childbearing potential requires weighing potential benefits to the mother against the risks to the fetus

• Antiepileptic Drug Pregnancy Registry: 1-888-233-2334, www.aedpregnancyregistry.org

• Taper drug if discontinuing

• Seizures, even mild seizures, may cause harm to the embryo/fetus

• Lack of definitive evidence of efficacy for chronic neuropathic pain or anxiety disorders suggests risk/benefit ratio is in favor of discontinuing tiagabine during pregnancy for those indications

Breast Feeding

• Some drug is found in mother’s breast milk

• Recommended either to discontinue drug or bottle feed

• If drug is continued while breast feeding, infant should be monitored for possible adverse effects

• If infant shows signs of irritability or sedation, drug may need to be discontinued