Aromatic L-amino acid decarboxylase inhibitor


"DDCI" redirects here. For the software company, see DDC-I. For the Deputy Director of the CIA, see Deputy Director of the Central Intelligence Agency.
Peripheral inhibitors of DOPA decarboxylase (AADC) block one of two ways levodopa can be inactivated before it reaches the central nervous system and is activated to dopamine. (Dopamine in the periphery only causes side effects, no antiparkinson effect.) COMT inhibitors block the second way.[1]

An aromatic L-amino acid decarboxylase inhibitor (synonyms: DOPA decarboxylase inhibitor, extracerebral decarboxylase inhibitor, DDCI and AAADI) is a medication of type enzyme inhibitor which inhibits the synthesis of dopamine by the enzyme aromatic L-amino acid decarboxylase (AADC, AAAD, or DOPA decarboxylase). It is used to inhibit the decarboxylation of L-DOPA to dopamine outside the brain, i.e. in the blood. This is primarily co-administered with L-DOPA to combat Parkinson's disease. Administration can prevent common side-effects, such as nausea and vomiting, as a result of interaction with D2 receptors in the vomiting center (or cheomoreceptor trigger zone) located outside the blood–brain barrier.[2]

Examples of extracerebral decarboxylase inhibitors include carbidopa and benserazide.

  1. ^ Mutschler, Ernst; Schäfer-Korting, Monika (2001). Arzneimittelwirkungen (in German) (8 ed.). Stuttgart: Wissenschaftliche Verlagsgesellschaft. pp. 313–316. ISBN 3-8047-1763-2.
  2. ^ Calne, D. B.; Reid, J. L.; Vakil, S. D.; Rao, S.; Petrie, A.; Pallis, C. A.; Gawler, J.; Thomas, P. K.; Hilson, A. (1971). "Idiopathic Parkinsonism treated with an extracerebral decarboxylase inhibitor in combination with levodopa". British Medical Journal. 3 (5777): 729–732. doi:10.1136/bmj.3.5777.729. PMC 1798919. PMID 4938431.