A fixed-dose combination antiparkinsonian agent. Levodopa is a dopamine precursor that crosses the blood-brain barrier and is converted to dopamine in the basal ganglia. Benserazide is a peripheral dopa-decarboxylase inhibitor that prevents the peripheral conversion of levodopa to dopamine, thereby increasing its central bioavailability and reducing peripheral side effects like nausea and vomiting. This combination is a cornerstone therapy for Parkinson's disease in India.
Adult: Initial: 1/2 tablet (Levodopa 100mg + Benserazide 25mg) once or twice daily. Titrate slowly by 1/2 tablet every 3-4 days based on response and tolerance. Usual maintenance: 3-8 tablets (Levodopa 600-1600mg + Benserazide 150-400mg) per day in 3-5 divided doses. Individualize therapy.
Note: Take on an empty stomach, 30-60 minutes before meals or 1-2 hours after meals to enhance absorption. If nausea occurs, may take with a small, low-protein snack (e.g., crackers). Swallow whole with water. Do not crush or chew. If a dose is missed, take it as soon as remembered unless it's almost time for the next dose. Do not double the dose.
Levodopa, the metabolic precursor of dopamine, crosses the blood-brain barrier via the large neutral amino acid (LNAA) transporter. Inside the nigrostriatal neurons, it is decarboxylated by aromatic L-amino acid decarboxylase (AADC) to form dopamine, replenishing the depleted striatal dopamine levels characteristic of Parkinson's disease. Benserazide, a peripheral AADC inhibitor, does not cross the BBB. It inhibits the conversion of levodopa to dopamine in peripheral tissues, allowing more levodopa to reach the brain and reducing peripheral dopamine-mediated adverse effects.
Pregnancy: Category C (US FDA). Animal studies show teratogenicity. Use only if potential benefit justifies potential fetal risk. Adequate human data lacking.
Driving: May cause dizziness, syncope, and sudden episodes of somnolence. Patients should be cautioned against driving or operating machinery until their individual response is known.
| Non-selective MAO Inhibitors (e.g., Phenelzine, Tranylcypromine) | Risk of hypertensive crisis, hyperpyrexia | Contraindicated |
| Antipsychotics (Typical: Haloperidol, Chlorpromazine; Atypical: Risperidone) | Antagonize dopaminergic effect, worsening parkinsonism | Major |
| Antihypertensives | Additive hypotensive effect | Moderate |
| Ferrous Sulfate/Iron Supplements | Reduces absorption and bioavailability of levodopa | Moderate |
| Metoclopramide | Antagonizes central dopaminergic effect | Major |
| Pyridoxine (Vitamin B6) in high doses (>10mg) | Reverses the effect of peripheral decarboxylase inhibitor, reducing efficacy | Moderate |
| Protein-rich foods / Dietary Amino Acids | Competes for absorption, reduces efficacy | Moderate |
| Dopamine D2 receptor antagonists (e.g., Metoclopramide) | Decreased efficacy of levodopa | Major |
| Anticholinergics (e.g., Trihexyphenidyl) | May improve tremor but can worsen confusion/delirium | Moderate |
| COMT Inhibitors (e.g., Entacapone) | Increases and prolongs levodopa effect, increases dyskinesia risk | Moderate (requires dose adjustment) |
Same composition (Levodopa (200mg) + Benserazide (50mg)), different brands: