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# Levodopa + benserazide

The other levodopa combination, common outside the US. Benserazide plays the same role as carbidopa: it stops levodopa being wasted outside the brain.

Updated 2026-11-01

- Class: [Dopaminergic antiparkinson agents (levodopa and amantadine)](https://durgical.com/en/pharmacology/classes/dopaminergic-antiparkinson-agents/)
- Enzyme: Aromatic L-amino acid decarboxylase (DOPA decarboxylase)
- ATC code: N04BA02

Also called: Co-beneldopa

✂**Aromatic L-amino acid decarboxylase (DOPA decarboxylase)**Levodopa + benserazide

ⓘ The figure shows carbidopa, which acts like benserazide, bound to pig DOPA decarboxylase; both inhibitors block this enzyme outside the brain.

**Target in 3D:** Aromatic L-amino acid decarboxylase (DOPA decarboxylase). PDB structure 1JS3 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/1JS3) · Drag to rotate · pinch to zoom

## Mechanism of action

As with carbidopa, benserazide inhibits aromatic L-amino acid decarboxylase in the periphery without entering the brain. More levodopa crosses into the brain and is converted to dopamine in the striatum, with less nausea and hypotension from dopamine made in the blood.

- Benserazide blocks DOPA decarboxylase outside the brain
- More levodopa crosses the blood-brain barrier
- Striatal dopamine is restored; movement improves

## Pharmacokinetics

**Absorption**
Capsules, slow-release capsules and dispersible tablets; protein, iron and antacids can reduce absorption

**Onset and duration**
Effect begins after the first dose; full effect can take a few weeks

## Indications

- Motor symptoms of Parkinson disease (tremor, slowness, stiffness) [Parkinson disease →](https://durgical.com/en/conditions/parkinson-disease/)

## Adverse effects

### Common

- Nausea, vomiting and loss of appetite
- Dizziness on standing
- Insomnia and taste change
- Dyskinesias, more with long use or high doses
- Discoloured urine, saliva or teeth (harmless)

### Serious (rare, important)

- Hallucinations, delusions and mood changes
- Impulse-control disorders and dopamine dysregulation syndrome (craving extra doses)
- Sudden sleep during the day
- Gastrointestinal bleeding; blood disorders (infections, bruising)

## Contraindications

- Hypersensitivity to levodopa or benserazide
- Not usually given to people under 25
- Caution: glaucoma, melanoma, psychosis, heart disease, peptic ulcer, liver or kidney disease

## Key interactions

**Nonselective MAO inhibitors (tranylcypromine, phenelzine, isocarboxazid)**
Dangerous rise in blood pressure; avoided, including within two weeks

**Antipsychotics (haloperidol, risperidone) and antiemetics (metoclopramide, prochlorperazine)**
Block dopamine and reduce the effect

**Iron supplements and antacids**
Change absorption

**Antihypertensives**
More dizziness on standing

## What is monitored

- Motor response, dyskinesias and off periods
- Mood, hallucinations, impulse control and daytime sleep
- Blood pressure lying and standing
- Skin checks for melanoma

## Administration and safety

- Given at the same times each day
- Never stopped suddenly; the team plans how to continue it around surgery
- Standard, slow-release and dispersible forms are not interchangeable

## Nursing care

- Give doses on time in hospital: missed doses cause off periods
- Check orthostatic blood pressure and falls
- Ask about gambling, shopping, eating or sexual changes and craving for extra doses
- Explain that coloured urine or saliva is harmless

## Pregnancy and breastfeeding

Rarely used in pregnancy because information is limited; it may be used when benefits outweigh risks.

## Memory aid

«Benserazide = carbidopa's twin»: same job, different country.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the role of benserazide in levodopa + benserazide?

It inhibits peripheral DOPA decarboxylase, like carbidopa, so more levodopa reaches the brain.

## Which antiemetics should be avoided with levodopa + benserazide?

Dopamine blockers such as metoclopramide and prochlorperazine.

## What is dopamine dysregulation syndrome?

Compulsive craving for more levodopa than is needed to control symptoms.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/levodopa-benserazide/)

## Related drugs

- [Levodopa + carbidopa](https://durgical.com/en/pharmacology/levodopa-carbidopa/)
- [Entacapone](https://durgical.com/en/pharmacology/entacapone/)

## Related conditions

- [Parkinson disease](https://durgical.com/en/conditions/parkinson-disease/)

[← Back to the class: Dopaminergic antiparkinson agents (levodopa and amantadine)](https://durgical.com/en/pharmacology/classes/dopaminergic-antiparkinson-agents/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [About co-beneldopa](https://www.nhs.uk/medicines/co-beneldopa/about-co-beneldopa/) (NHS, 2025); [Side effects of co-beneldopa](https://www.nhs.uk/medicines/co-beneldopa/side-effects-of-co-beneldopa/) (NHS, 2025); [Who can and cannot take co-beneldopa](https://www.nhs.uk/medicines/co-beneldopa/who-can-and-cannot-take-co-beneldopa/) (NHS, 2025); [Taking co-beneldopa with other medicines and herbal supplements](https://www.nhs.uk/medicines/co-beneldopa/taking-co-beneldopa-with-other-medicines-and-herbal-supplements/) (NHS, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/levodopa-benserazide/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/levodopa-benserazide/