Anticonvulsants [Neurosurgery Wiki]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== Anticonvulsants ======

Anticonvulsants (also known as antiepileptic drugs, AEDs) are medications used primarily to prevent and control seizures. Many also have indications in neuropathic pain, mood stabilization, and other neurologic or psychiatric conditions.

===== Classification =====
  * **Drug class:** Antiepileptic / anticonvulsant agents
  * **ATC code:** N03A
  * **Mechanisms of action (varies by drug):**
    * Sodium channel blockers (e.g., phenytoin, carbamazepine)
    * Calcium channel blockers (e.g., ethosuximide)
    * GABA enhancers (e.g., phenobarbital, gabapentin)
    * Glutamate inhibitors (e.g., perampanel)
    * Synaptic vesicle protein modulators (e.g., levetiracetam)

===== Clinical Indications =====
  * **Epilepsy** (partial and generalized seizures)
  * **Status epilepticus**
  * **Neuropathic pain** (e.g., postherpetic neuralgia, diabetic neuropathy)
  * **Bipolar disorder** (e.g., valproate, lamotrigine)
  * **Migraine prophylaxis** (e.g., topiramate)
  * **Off-label**: tinnitus, fibromyalgia, anxiety disorders

===== Common Anticonvulsants =====
^ Drug ^ Main Indication ^ Notes ^
| **Phenytoin** | Focal seizures | Nonlinear kinetics; gingival hyperplasia |
| **Valproic acid** | Generalized seizures, bipolar disorder | Teratogenic; hepatotoxicity risk |
| **Carbamazepine** | Focal seizures, trigeminal neuralgia | Risk of hyponatremia, agranulocytosis |
| **Lamotrigine** | Broad-spectrum, bipolar disorder | Rash, risk of Stevens-Johnson syndrome |
| **Levetiracetam** | Broad-spectrum | Behavioral side effects |
| **Topiramate** | Epilepsy, migraine | Weight loss, cognitive slowing |
| **Gabapentin / Pregabalin** | Neuropathic pain, seizures | Renally excreted, well tolerated |

===== Adverse Effects =====
  * **Common:** Drowsiness, dizziness, ataxia, GI upset
  * **Serious:** Stevens-Johnson syndrome, hepatotoxicity, blood dyscrasias, teratogenicity
  * **Neuropsychiatric:** Mood changes, suicidal ideation (monitor closely)

===== Drug Interactions =====
  * Many are **CYP450 inducers or inhibitors** (especially older agents)
  * Monitor plasma levels if narrow therapeutic index (e.g., phenytoin, valproate)
  * Avoid combinations that lower seizure threshold (e.g., certain antibiotics, antidepressants)

===== Monitoring =====
  * Liver function tests (e.g., valproate, carbamazepine)
  * CBC (e.g., carbamazepine, ethosuximide)
  * Serum drug levels when indicated
  * Mood and behavior (especially in adolescents)

===== Special Considerations =====
  * Choose based on **seizure type**, **comorbidities**, **age**, and **pregnancy status**
  * Some agents have **off-label uses** beyond epilepsy
  * **Teratogenicity** is a major concern — avoid valproate in women of childbearing age unless no alternatives

===== Synonyms =====
  * Antiepileptic drugs (AEDs)
  * Antiseizure medications (ASMs)

===== Related Topics =====
  * [[epilepsy|Epilepsy]]
  * [[neuropathic_pain|Neuropathic pain]]
  * [[GABA|GABAergic system]]
  * [[mood_stabilizers|Mood stabilizers]]