Adjunct drugs for partial seizures - 14 drugs
Clorazepate Felbamate Gabapentin Lamotrigine Topiramate Tiagabine Levetiracetam Zonizamide Pregabalin Vigabatrin Lacosamide Ezogabine Rufinamide Clobazam
Clorazepate - MOA
Enhances GABA-mediated chloride influx
Clorazepate - indications
Anxiety disorders.
Partial seizures.
Clorazepate - Adverse effects
Confusion
Drowsiness
Drug tolerance
Lethargy
Clorazepate - interactions
Decreased met by: Cimetidine and disulfiram.
Increased met by: rifampin.
Clonazepam increases CNS depression with alcohol
Felbamate - MOA
Blocks glycine coactivation of NMDA receptors, inhibits the initiation of seizures.
Felbamate - Indications
Limited to partial seizures that are refractory to other drugs.
Felbamate - contraindications
Bone marrow depression, hepatic disease, hypersensitivity
Felbamate - adverse effects
Aplastic anemia (fatal), fatigue, GI reactions, headache, hepatic toxicity and acute failure, insomnia
Felbamate - interactions
Increased met by: Carbamazepine, phenytoin. Increased CNS depression with alcohol
Gabapentin - MOA
Increases GABA release
Gabapentin - indications
Partial seizures.
Postherpetic neuralgia.
Restless leg syndrome.
Gabapentin - adverse effects
(usually minimal)
Ataxia, dizziness, drowsiness, nystagmus, tremor
Lamotrigine - MOA
Blocks voltage-sensitive Na+ channels, interfering with neuronal membrane conduction and release of excitatory neurotransmitters
Lamotrigine - Clinical use
Partial seizures.
Generalized tonic-clonic, atonic and absence seizures.
Lennox-Gastaut syndrome.
Manic phase of bipolar disorder.
Lamotrigine - contraindications
Hypersensitivity. Use cautiously in pts who are taking valproate or have hepatic/renal disease
Lamotrigine - adverse effects
Ataxia, diplopia, dizziness, drowsiness, headache, nausea, rash, Steven-Johnson syndrome. Risk of aseptic meningitis
Lamotrigine - interactions
Decreased met by: valproate. Increased met by: Carbamazepine, phenobarbital and phenytoin. Decreases levels of valproate.
Which drugs can be used in LGS?
Lamotrigine
Rufinamide (only this indication)
Clobazam
Rufinamide - MOA
Modulates activity of Na+ channels, and prolongs the inactive state of the channel
Clobazam - MOA
Increase inhibition by GABA at GABAa receptors
Clorazepate, felbamate, gabapentin and lamotrigine - safety in pregnancy
All are category C.
Lamotrigine may decrease folate levels.
