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Bipolar disorder - Management
What are the drug interactions of valproate?
- Valproate is highly protein bound (up to 94%), and other drugs that are also highly protein bound (e.g. aspirin) may displace valproate from albumin and precipitate toxicity.
- Other less strongly protein-bound drugs (e.g. warfarin) can be displaced by valproate; this may lead to higher free levels and increased therapeutic effect or toxicity of the concomitant drug.
- Valproate is metabolized by the liver, so drugs that inhibit cytochrome P450 enzymes (e.g. erythromycin, fluoxetine, and cimetidine) can increase valproate levels.
- Valproate can increase the plasma levels of some drugs, possibly by inhibition of their metabolism (e.g. tricyclic antidepressants, particularly clomipramine).
[Taylor et al, 2007]
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