Melevodopa/carbidopa

Melevodopa/Carbidopa

Chemical structure of Melevodopa

Melevodopa/carbidopa is a combination medication used in the treatment of Parkinson's disease. It consists of two active ingredients: melevodopa, a prodrug of levodopa, and carbidopa, a peripheral decarboxylase inhibitor. This combination is designed to enhance the delivery of levodopa to the brain while minimizing peripheral side effects.

Mechanism of Action

Melevodopa is a methyl ester of levodopa, which is a precursor to the neurotransmitter dopamine. In patients with Parkinson's disease, dopamine levels in the brain are significantly reduced due to the degeneration of dopaminergic neurons in the substantia nigra. Levodopa is converted to dopamine in the brain, helping to replenish the diminished levels and alleviate symptoms such as bradykinesia, rigidity, and tremor.

Carbidopa works by inhibiting the enzyme aromatic L-amino acid decarboxylase (AADC) in the periphery. This enzyme is responsible for the conversion of levodopa to dopamine outside the central nervous system. By inhibiting this conversion, carbidopa increases the availability of levodopa to cross the blood-brain barrier and reduces peripheral side effects such as nausea and vomiting.

Pharmacokinetics

Melevodopa is rapidly absorbed from the gastrointestinal tract and is converted to levodopa in the bloodstream. The presence of carbidopa enhances the bioavailability of levodopa by preventing its premature conversion to dopamine in the periphery. This allows for a greater proportion of levodopa to reach the brain, where it can exert its therapeutic effects.

Clinical Use

Melevodopa/carbidopa is primarily used in the management of Parkinson's disease. It is particularly beneficial in patients who experience "wearing-off" effects with standard levodopa/carbidopa therapy. The combination may provide a more stable plasma concentration of levodopa, leading to improved motor control and reduced fluctuations in symptom severity.

Side Effects

Common side effects of melevodopa/carbidopa include:

• Nausea
• Dizziness
• Orthostatic hypotension
• Dyskinesia

Less common but more serious side effects can include:

• Hallucinations
• Confusion
• Impulse control disorders

Administration

Melevodopa/carbidopa is typically administered orally. The dosage and frequency depend on the individual patient's needs and response to therapy. It is important for patients to follow their healthcare provider's instructions closely to optimize treatment outcomes.

==

Chemical structure of Carbidopa

Related Pages

• Parkinson's disease
• Levodopa
• Dopamine
• Substantia nigra
• Blood-brain barrier