Dopa decarboxylase inhibitor

An aromatic L-amino acid decarboxylase inhibitor (synonyms: DOPA decarboxylase inhibitor, DDCI and AAADI) is a drug which inhibits the synthesis of dopamine by the enzyme aromatic L-amino acid decarboxylase (AADC, AAAD, or DOPA decarboxylase).

Peripheral DDCIs incapable of crossing the protective blood-brain-barrier (BBB) are used in augmentation of L-DOPA (levodopa) in the treatment of Parkinson's disease (PD) to block the peripheral conversion of L-DOPA into dopamine for the purpose of reducing adverse side effects. Combined l-dopa and DDCI therapy does not inherently decrease peripheral cardiovascular side effects of l-dopa administration; however, combined therapy potentiates the central effects of l-dopa by decreasing the dose-dependency 4-5 fold, therein allowing for effective Parkinson's Disease treatment without cardiovascular risk associated with high peripheral dopamine.

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