Levodopa / Carbidopa / Entacapone

What it is and how it works

Mechanism of Action Levodopa Current evidence indicates that symptoms of Parkinson’s disease are related to depletion of dopamine in the corpus striatum. Administration of dopamine is ineffective in the treatment of Parkinson’s disease because it does not cross the blood-brain barrier. However, levodopa the metabolic precursor of dopamine, does cross the blood-brain barrier, and is presumably converted to dopamine in the brain. This is thought to be the mechanism whereby levodopa relieves the symptoms of Parkinson’s disease.

Mechanism class: Catechol O-Methyltransferase Inhibitors · DOPA Decarboxylase Inhibitors

Indications

Carbidopa, levodopa and entacapone tablets, are indicated for the treatment of Parkinson’s disease. Carbidopa, levodopa and entacapone tablets can be used: To substitute (with equivalent strengths of each of the three components) carbidopa/levodopa and entacapone previously administered as individual products. To replace carbidopa/levodopa therapy (without entacapone) when patients experience the signs and symptoms of end-of-dose “wearing-off” and when they have been taking a total daily dose of levodopa of 600 mg or less and have not been experiencing dyskinesias. Carbidopa, levodopa and entacapone tablets, a combination drug consisting of levodopa (aromatic amino acid), carbidopa (aromatic amino acid decarboxylation inhibitor), and entacapone (catechol-O-methyltransferase (COMT) inhibitor) is indicated for the treatment of Parkinson’s disease.

Dosage and administration (summary)

Carbidopa, levodopa and entacapone tablets should be used as a substitute for patients already stabilized on equivalent doses of carbidopa/levodopa and entacapone. However, some patients who have been stabilized on a given dose of carbidopa/levodopa may be treated with carbidopa, levodopa and entacapone tablets if a decision has been made to add entacapone (see below). Therapy should be individualized and adjusted according to the desired therapeutic response. Evaluate vitamin B6 levels prior to starting treatment with carbidopa/levodopa therapies.

Contraindications

Carbidopa, levodopa and entacapone tablets are contraindicated in patients: Taking nonselective monoamine oxidase (MAO) inhibitors (e.g., phenelzine and tranylcypromine). These nonselective MAO inhibitors must be discontinued at least two weeks prior to initiating therapy with carbidopa, levodopa and entacapone tablets. With narrow-angle glaucoma. Concomitant use of nonselective monoamine oxidase (MAO) inhibitors Narrow-angle glaucoma

Warnings and precautions

The following adverse reactions described in this section are related to at least one of the components of carbidopa, levodopa and entacapone tablets (i.e., levodopa, carbidopa, and/or entacapone) based upon the safety experience in clinical trials (especially pivotal trials) or in postmarketing reports.

Pregnancy

Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of carbidopa, levodopa and entacapone tablets in pregnant women. In animals, administration of carbidopa-levodopa or entacapone during pregnancy was associated with developmental toxicity, including increased incidences of fetal malformations (see Da…

Storage and supply

Carbidopa, levodopa and entacapone tablets are supplied as film-coated tablets for oral administration in the following six strengths: Carbidopa, levodopa and entacapone film-coated tablets 12.5 mg/50 mg/200 mg containing 12.5 mg of carbidopa, 50 mg of levodopa and 200 mg of entacapone.

Source: Carbidopa, Levodopa And Entacapone (Carbidopa, Levodopa And Entacapone) — US FDA prescribing information, 2026-04-08, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.