Branched-chain Amino Acids (bcaa) - Benserazide, Levodopa Interaction
Herbal: Branched-chain Amino Acids (bcaa)
Drug: Benserazide, Levodopa
Brand names:
Prolopa, Madopar

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
Benserazide, Levodopa is classified as belonging to the following category: Levodopa
BCAAs in large doses can reduce the effects of levodopa.
BCAAs may compete with levodopa for transport systems in the intestine and brain and decrease the effectiveness of levodopa. Small clinical studies how that concomitant ingestion of protein or high doses of leucine or isoleucine (100 mg/kg) and levodopa can exacerbate tremor, rigidity, and the "on-off" syndrome in patients with Parkinson disease.
Interaction Rating
Likelihood of Occurrence
ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
References
- Rosen HM, Yoshimura N, Hodgman JM, Fischer JE. Plasma amino acid patterns in hepatic encephalopathy of differing etiology. Gastroenterology 1977;72:483-7.
- DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
- Nutt JG, Woodward WR, Hammerstad JP, et al. The "on-off" phenomenon in Parkinson's disease. Relation to levodopa absorption and transport. N Engl J Med 1984;310:483-8.
- Baruzzi A, Contin M, Riva R, et al. Influence of meal ingestion time on pharmacokinetics of orally administered levodopa in parkinsonian patients. Clin Neuropharmacol 1987;10:527-37.
- Juncos JL, Fabbrini G, Mouradian MM, et al. Dietary influences on the antiparkinsonian response to levodopa. Arch Neurol 1987;44:1003-5.
- Eriksson T, Granerus AK, Linde A, et al. "On-off" phenomenon in Parkinson's disease: relationship between dopa and other large neutral amino acids in plasma. Neurology 1988;38:1245-8.
Branched-chain Amino Acids (bcaa) - More Interactions
Branched-chain Amino Acids (bcaa) interacts with 89 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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