Benserazide

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Benserazide
Systematic (IUPAC) name
2-amino-3-hydroxy-N'-[(2,3,4-trihydroxyphenyl) methyl]propanehydrazide
Identifiers
CAS number	14919-77-8
ATC code	?
PubChem	2327
Chemical data
Formula	C10H15N3O5
Mol. mass	293.71 g/mol
Pharmacokinetic data
Bioavailability	?
Metabolism	?
Half life	?
Excretion	Renal and fecal
Therapeutic considerations
Pregnancy cat.	B3(AU)
Legal status	POM(UK) (with levodopa)
Routes	?

Benserazide (also called Serazide or Ro 4-4602) is a DOPA decarboxylase inhibitor which is unable to cross the blood-brain barrier. It is used in the management of Parkinson's disease in combination with L-DOPA (levodopa) as Co-Beneldopa (BAN), under the brand names Madopar in the UK and Prolopa in Canada, both made by Roche. Benserazide is not approved for use in the US; carbidopa is used instead for the same purpose. These combinations are also used for Restless Legs Syndrome^[1].

[edit] Function

Levodopa is a dopamine precursor which is administered to increase levels of dopamine in the Central Nervous System. However, most levodopa is decarboxylated to dopamine before it reaches the brain, and dopamine is unable to cross the blood-brain barrier. This means less dopamine is available to the CNS, and excess dopamine is circulated in extracerebral tissues, causing major adverse effects.

Benserazide inhibits this decarboxylation, allowing the levodopa to enter the brain instead. Because benserazide does not enter the CNS, DOPA decarboxylase is uninhibited there and metabolizes the levadopa into useful dopamine. Adverse effects caused by extracerebral dopamine, such as nausea and arrhythmia, are minimized. However, benserazide cannot reduce the CNS-mediated side effects of levodopa, particularly dyskinesia.

Benserazide has little therapeutic effect on its own, and is only administered in combination with levodopa.

[edit] References