Levomed Mechanism of Action

LEVOMED is a combination of Carbidopa, an aromatic amino acid decarboxylase inhibitor, and Levodopa, the metabolic precursor of dopamine, for the treatment of Parkinson's disease and syndrome.
Levodopa relieves the symptoms of Parkinson's disease presumably by being decarboxylated to dopamine in the brain. Carbidopa, which does not cross the blood-brain barrier, inhibits only the extracerebral decarboxylation of Levodopa, making more Levodopa available for transport to the brain and subsequent conversion to dopamine; This obviates the necessity for large doses of Levodopa at frequent intervals. The lower dosage reduces or eliminates many adverse reactions some of which are attributable to dopamine being formed in extracerebral tissues.
When used as recommended, LEVOMED improves overall therapeutic response as compared to Levodopa.
LEVOMED provides effective long-lasting Levodopa plasma levels at doses that are approximately 80 percent lower than those needed with Levodopa alone.
While pyridoxine hydrochloride (Vitamin B6) is known to accelerate the peripheral metabolism of Levodopa to dopamine, Carbidopa prevents this action. In a study in which patients received 100 to 500mg of pyridoxine a day while being treated with Carbidopa and Levodopa in combination, there was no reversal of antiparkinsonian effect.
Clinical Advantages: LEVOMED usually reduces and in some patients eliminates certain side effects found most frequently in patients on Levodopa: anorexia, nausea, vomiting, cardiac arrhythmia, postural hypotension and dizziness.
By reducing certain of the dose-limiting side effects produced by Levodopa alone, LEVOMED permits more patients to obtain adequate relief of the symptoms of Parkinson's disease.
LEVOMED offers prompt therapeutic response. Response to LEVOMED has been observed in one day; sometimes after one dose.
LEVOMED minimizes the slow individual dosage titrations which were needed with Levodopa therapy.
Fully effective doses are usually reached within seven days compared to weeks or months with Levodopa.
Following administration of LEVOMED, plasma levels of Levodopa were increased approximately five times over those found when the same dosage of Levodopa was given alone.
Levodopa-responders can be transferred to LEVOMED.
LEVOMED reduces the fluctuations of patient response often seen with Levodopa.
LEVOMED may be used with other standard antiparkinsonian drugs, where needed.
LEVOMED may be given to patients taking multivitamin preparations that include pyridoxine (Vitamin B6).