How Do Other Anticonvulsants Work?

Anticonvulsants are medications used to treat different types of seizures, including convulsions, other neurological disorders that cause nerve pain (neuralgia), and bipolar I disorder. Medications that do not fall into any specific class of anticonvulsants are categorized as other anticonvulsants.

Other anticonvulsants include the following medications which work in different ways:

• Acetazolamide: Acetazolamide is used to treat edema from congestive heart failure, drug-induced edema, glaucoma, altitude sickness, and seizures. Acetazolamide works by inhibiting the activity of carbonic anhydrase, an enzyme that plays a role in the reabsorption of minerals in the kidneys, and the conversion of carbon dioxide in red cells.
  • Acetazolamide increases the excretion of sodium, potassium, bicarbonate, and water in the urine, leading to a decrease in intraocular pressure, intracranial pressure, and blood pressure. Bicarbonate loss increases blood acidity resulting in hyperventilation and an increase in oxygen intake. Carbonic anhydrase inhibition in the brain reduces seizure activity by reducing abnormal firing in the nerve cells (neurons).
• Carbamazepine: Carbamazepine is used in the treatment of neurological conditions such as epilepsy and trigeminal neuralgia and as a mood stabilizer in bipolar I disorder. Carbamazepine reduces abnormal electrical activity in the brain by blocking the sodium channels in the neurons, making them stable and less excitable.
• Cenobamate: The exact mechanism of carbamate in seizure treatment is unclear, it is thought to work by reducing repetitive firing of neurons by inhibiting sodium currents. Studies show that cenobamate also enhances the activity of gamma-aminobutyric acid (GABA) an inhibitory chemical messenger (neurotransmitter) in the brain.
• Divalproex sodium: Divalproex sodium is a stable compound of valproic acid and sodium valproate used in the treatment of seizures and bipolar mania. Divalproex sodium is believed to work by increasing the levels of the neurotransmitter GABA, enhancing its activity in the brain, and also inhibiting sodium and calcium channels in the neurons.
• Eslicarbazepine acetate: Eslicarbazepine acetate is a drug used in the treatment of partial-onset seizures. Eslicarbazepine is thought to inhibit the repetitive firing of neurons by blocking sodium channels and stabilizing the neuronal membranes. Eslicarbazepine may also enhance potassium conductance and modulate activated calcium channels.
• Felbamate: Felbamate is an antiepileptic drug used to treat severe seizures that are not adequately controlled with other medications. Felbamate has effects equivalent to other anticonvulsants, however, its exact mechanism of action is unknown. Studies show that felbamate may reduce seizure spread and increase the seizure threshold.
• Fenfluramine: Fenfluramine is used to treat seizures associated with Dravet syndrome, a severe form of epilepsy. Fenfluramine increases the levels and enhances the activity of serotonin, a neurotransmitter that regulates many vital systems including sleep, digestion, cognition, mood, and behavior.
• Lacosamide: Lacosamide is an antiepileptic drug that slowly inactivates sodium channels, stabilizing the neuronal membrane and inhibiting the repetitive firing of neurons. Lacosamide also has neuroprotective effects and may inhibit repetitive seizures by binding to collapsin response mediator protein-2 (CRMP-2), a phosphoprotein in the nervous system.
• Lamotrigine: Lamotrigine is an antiepileptic drug used in the treatment of seizures and bipolar I disorder. Lamotrigine inhibits the release of glutamate, an excitatory neurotransmitter, and inhibits sodium channels, stabilizing the neuronal membrane and reducing electrical activity.
• Oxcarbazepine: Oxcarbazepine is used in the treatment of partial seizures and works by blocking the voltage-sensitive sodium channels, stabilizing and reducing the excitability of neuronal membranes. This inhibits repetitive firing and propagation of nerve impulses to other parts of the brain. Oxcarbazepine also enhances potassium conductance and modulates activated calcium channels.
• Pregabalin: Pregabalin is used to treat nerve pain (neuralgia) associated with neurological disorders including diabetic neuropathy, postherpetic neuralgia, and fibromyalgia. Pregabalin binds to a subunit of the neuronal calcium channels and modulates the release of excitatory neurotransmitters, reducing pain signal transmission.
• Rufinamide: Rufinamide is used to treat seizures associated with Lennox-Gastaut syndrome, a severe type of epilepsy. Rufinamide modulates the activity of sodium channels, prolonging their inactive state, which inhibits repetitive neuronal firing.
• Stiripentol: Stiripentol is used to treat seizures associated with Dravet syndrome as an adjunct to clobazam, a benzodiazepine class of medication. Possible mechanisms of action are enhancing the activity of gamma-butyric acid (GABA) and inhibiting the enzyme cytochrome P450, which increases the blood levels and bioavailability of clobazam.
• Tiagabine: Tiagabine is used as an adjunctive therapy to treat partial seizures. Tiagabine enhances the levels and activity of gamma-butyric acid, the major inhibitory neurotransmitter in the central nervous system, by blocking its reabsorption (reuptake) by the neurons.
• Topiramate: Topiramate is used to treat seizures and to prevent migraines. Topiramate is believed to be effective in reducing seizures and preventing migraine in multiple ways, including blocking sodium channels, enhancing GABA’s inhibitory activity, reducing glutamate’s excitatory effects, and inhibiting carbonic anhydrase enzyme.
• Valproic acid: Valproic acid is used to treat complex seizures, bipolar mania and as prophylaxis for migraine. Valproic acid is thought to work by increasing the levels of GABA, enhancing or mimicking the action of GABA, and also by inhibiting sodium and calcium levels.
• Vigabatrin: Vigabatrin is used to treat refractory complex partial seizures that are not adequately controlled with less toxic medications. Vigabatrin increases the brain concentrations of the inhibitory neurotransmitter GABA by inhibiting GABA transaminase, an enzyme that breaks down GABA.
• Zonisamide: Zonisamide is used to treat partial seizures and is more effective for the tonic (rigidity) phase than the clonic (convulsion) phase of the seizure. Zonisamide is believed to work by stabilizing the neuronal membranes by acting on the sodium and calcium channels. Zonisamide does not affect the neurotransmitters GABA or glutamate. 

Other anticonvulsants may be administered as:

• Oral: Tablets, chewable tablets, capsules, suspensions, and syrups
• Injections: Intravenous (IV) injection into the vein

Other anticonvulsants may be used in the treatment of conditions that include:

• Acetazolamide:
  • Glaucoma (progressive eye disease with increased intraocular pressure that damages the optic nerve)
  • Acute altitude sickness
  • Congestive heart failure-associated edema
  • Seizure
  • Drug-induced edema
  • Epilepsy
• Carbamazepine:
  • Epilepsy
  • Trigeminal neuralgia (a condition that causes intense nerve pain in the face due to irritation of the trigeminal nerve, a facial nerve)
  • Acute manic or mixed episodes of bipolar I disorder
  • Postherpetic neuralgia (residual nerve pain after shingles attack)
  • Restless legs syndrome (off-label)
  • Schizophrenia (off-label)
• Cenobamate:
  • Partial onset seizures
• Divalproex sodium:
  • Manic episodes associated with bipolar I disorder
  • Epileptic seizures include:
    • Complex partial seizures
    • Simple and complex absence seizures
  • Migraine prophylaxis
• Eslicarbazepine acetate:
  • Partial onset seizures
• Felbamate:
  • Seizures inadequately controlled by other medications
  • Lennox-Gastaut syndrome (a severe type of epilepsy) adjunctive therapy in children above two years
• Fenfluramine:
  • Seizures associated with Dravet syndrome, rare drug-resistant epilepsy, in patients over two years of age
• Lacosamide:
  • Partial onset seizures
  • Primary generalized tonic-clonic seizures
• Lamotrigine:
  • Partial seizures
  • Primary generalized tonic-clonic seizures
  • Generalized seizures of Lennox-Gastaut syndrome
  • Maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes in patients treated with standard therapy
• Oxcarbazepine:
  • Partial onset seizures
  • Off-label uses include:
  • Bipolar I disorder
  • Diabetic neuropathy
  • Neuralgia/neuropathy
• Pregabalin:
  • Diabetic peripheral neuropathic pain
  • Postherpetic neuralgia
  • Fibromyalgia
  • Partial onset seizures
  • Neuropathic pain with spinal cord injuries
• Rufinamide:
  • Seizures associated with Lennox-Gastaut syndrome
• Stiripentol:
  • Seizures associated with Dravet syndrome in patients of two years and older, as an adjunct to clobazam
• Tiagabine:
  • Partial seizures, as an adjunctive therapy
• Topiramate:
  • Partial onset or primary generalized tonic-clonic seizures
  • Seizures associated with Lennox-Gastaut syndrome
  • Prophylaxis for migraine headache
  • Cluster headache (off-label)
  • Alcoholism (off-label)
• Valproic acid:
  • Complex partial seizures
  • Simple and complex absence seizures
  • Prophylaxis of migraine
  • Manic episodes of bipolar I disorder
  • Orphan designations include:
    • Fragile X syndrome (genetic disorder that causes learning disabilities and cognitive impairment)
    • Familial adenomatous polyposis (an inherited disorder that causes colon polyps which can develop into cancer)
    • Diffuse large B-cell lymphoma (a cancer of white blood cells)
    • Wolfram syndrome (an inherited disorder that affects multiple systems)
• Vigabatrin:
  • Adjunct therapy for complex partial seizures in patients with inadequate response to several seizure treatments and for whom the potential benefits outweigh the risk of vision loss
  • Infantile spasms in babies from age one month to two years, for whom the potential benefits outweigh the risk of vision loss
• Zonisamide:
  • Partial seizures, as an adjunct therapy in adults
  • Weight loss (off-label)

Side effects of other anticonvulsants vary with each drug. A few of the most common side effects may include:

• Acetazolamide:
  • Confusion
  • Convulsions
  • Drowsiness
  • Flaccid paralysis
  • Malaise
  • Paresthesia (abnormal skin sensation)
• Carbamazepine:
  • Ataxia (impaired balance, coordination, and speech)
  • Dizziness
  • Drowsiness
  • Nausea and vomiting
  • Dry mouth
  • Skin reactions such as Stevens-Johnson syndrome
• Cenobamate:
  • Somnolence (drowsiness)
  • Dizziness
  • Fatigue
  • Diplopia (double vision)
  • Headache
  • Increased blood potassium levels 
• Divalproex sodium:
  • Nausea and vomiting
  • Headache
  • Asthenia (weakness)
  • Somnolence
  • Tremor
  • Dizziness
  • Abdominal pain and diarrhea
• Eslicarbazepine acetate:
  • Dizziness
  • Headache
  • Somnolence
  • Nausea and vomiting
  • Diplopia
  • Blurred vision
• Felbamate:
  • Anorexia (loss of appetite)
  • Nausea and vomiting
  • Somnolence
  • Upper respiratory tract infection
  • Nervousness
  • Insomnia
• Fenfluramine:
  • Decreased appetite
  • Diarrhea
  • Fatigue, malaise, asthenia (weakness)
  • Somnolence, sedation, lethargy
  • Abnormal echocardiogram
  • Pyrexia (fever)
• Lacosamide:
  • Dizziness
  • Diplopia (double vision)
  • Blurred vision
  • Nausea and vomiting
  • Fatigue
  • Ataxia (impaired balance, coordination, and speech)
  • Nystagmus (uncontrolled eye movements)
• Lamotrigine:
  • Dizziness
  • Diplopia
  • Headache
  • Ataxia
  • Blurred vision
  • Rhinitis (inflammation of the nasal passage)
  • Somnolence
• Oxcarbazepine:
  • Dizziness
  • Diplopia
  • Headache
  • Nausea and vomiting
  • Nystagmus
  • Somnolence
  • Ataxia
• Pregabalin:
  • Dizziness
  • Somnolence/lethargy
  • Peripheral edema
  • Ataxia
  • Fatigue
  • Xerostomia (dry mouth)
  • Weight gain
• Rufinamide:
  • Diplopia
  • Dizziness
  • Fatigue
  • Headache
  • Somnolence
  • Nausea and vomiting
  • Stevens-Johnson syndrome
• Stiripentol:
  • Somnolence
  • Decrease in appetite
  • Decrease in weight
  • Ataxia
  • Agitation
  • Hypotonia (low muscle tone)
  • Tremor
• Tiagabine:
  • Dizziness
  • Asthenia
  • Somnolence
  • Nausea and vomiting
  • Abdominal pain
  • Diarrhea
  • Pharyngitis (throat inflammation)
• Topiramate:
  • Decrease in serum bicarbonate
  • Dizziness
  • Fatigue
  • Nervousness
  • Psychomotor slowing
  • Abnormal vision
  • Anorexia
• Valproic acid:
  • Nausea
  • Headache
  • Increased bleeding time
  • Thrombocytopenia (low platelet count in the blood)
  • Tremor
  • Alopecia (hair loss)
  • Asthenia
• Vigabatrin:
  • Weight gain
  • Permanent bilateral concentric visual field constriction
  • Fatigue
  • Somnolence
  • Headache
  • Dizziness
  • Hyperactivity in children
• Zonisamide:
  • Somnolence
  • Anorexia
  • Dizziness
  • Headache
  • Nausea
  • Agitation
  • Abdominal pain

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these products do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of some of the other anticonvulsants include:

• acetazolamide
• Aptiom
• Banzel
• carbamazepine
• Carbamazepine Chewtabs
• Carbamazepine CR
• Carbatrol
• Carnexiv
• cenobamate
• Depacon
• Depakene
• Depakote
• Depakote ER
• Depakote Sprinkles
• Diacomit
• Diamox Sequels (DSC)
• divalproex sodium
• Epitol
• Equetro
• eslicarbazepine acetate
• felbamate
• Felbatol
• fenfluramine
• Fintepla
• Gabitril
• lacosamide
• Lamictal
• Lamictal ODT
• Lamictal XR
• lamotrigine
• Lyrica
• Lyrica CR
• oxcarbazepine
• Oxtellar XR
• pregabalin
• Qudexy XR
• rufinamide
• Sabril
• Stavzor
• stiripentol
• Tegretol
• Tegretol XR
• Teril
• tiagabine
• Topamax
• topiramate
• Trileptal
• Trokendi XR
• valproic acid
• vigabatrin
• Vigadrone
• Vimpat
• Xcopri
• Zonegran
• zonisamide