1.2 Meq/L (the commonest first symptom of toxicity is coarse tremors & level above 1.8 Meq/L is the indication for hemodialysis) Valproate is a rapidly acting MS. (DOC for rapid cyclers - > 4 episodes per year) with multiple mechanisms (blockade of voltage-gated sodium channels, inhibition of GABA transaminase). It causes hemorrhagic pancreatitis, hepatic necrosis, hyperammonemia, midline defects (teratogenic). Carbamazepine is known to cause agranulocytosis, Steven-Johnson's syndrome, SIADH and often aggravates absence seizures & juvenile myoclonic epilepsy. Gabapentin is useful in "pain syndromes" & adjuvant to treat anxiety disorders.">