Interaction Details

There were no interactions found between Carbidopa, Levodopa and Passion Flower. This does not mean the potential for an interaction does not exist, however. There is often a lack of studies and data surrounding traditional medicine, especially concerning drug interactions, so it is important to always consult your provider before making any changes to your medication regimen.


Still looking for more information about combining Carbidopa, Levodopa and Passion Flower? Ask Dr. Brian Staiger about it by contacting him directly.

Pharmacist Analysis

Passionflower is not known to have many clinically significant drug interactions.

Nevertheless, it has been shown to have sedative effects, which can be additive when used in conjunction with sedative medications (e.g., Benadryl, benzodiazepines, opioids, etc...).

Therefore, we do list interactions between Passionflower and CNS (central nervous system) depressants or other drugs with strong sedative effects.

Additionally, certain constituents of Passionflower (such as apigenin and vitexin) may inhibit certain drug transports, specifically OATP2B1 and OATP1A2.

These are responsible for the uptake of certain drugs and other compounds into the body.

As Passionflower can inhibit these transports, it is possible that it might reduce the bioavailability of drugs that are substrates for these transporters but studies are far from conclusive on the matter.

There is no known drug interaction between Passionflower and the drug in question here, however.

As always, be sure to speak with your doctor before making any changes to your medication regimen.

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Passion Flower Overview

Passion Flower Passionflower (Passiflora incarnata) is a climbing vine with fragrant white and purple flowers that is native to the Americas. It is purported to have a number of potential health benefits, including reducing anxiety and improving sleep. It is thought to work by increasing the levels of GABA (gamma-aminobutyric acid), a neurotransmitter in the brain that helps regulate mood and anxiety. Passionflower may also have mild sedative and muscle-relaxing effects and may be helpful in the treatment of muscle spasms and other muscle disorders. Dietary supplements containing passionflower are generally standardized to contain no less than 1.5% of the flavanoid vitexin.
See More Information Regarding Passion Flower

Carbidopa, Levodopa Overview

  • The combination of levodopa and carbidopa is used to treat the symptoms of Parkinson's disease and Parkinson's-like symptoms that may develop after encephalitis (swelling of the brain) or injury to the nervous system caused by carbon monoxide poisoning or manganese poisoning. Parkinson's symptoms, including tremors (shaking), stiffness, and slowness of movement, are caused by a lack of dopamine, a natural substance usually found in the brain. Levodopa is in a class of medications called central nervous system agents. It works by being converted to dopamine in the brain. Carbidopa is in a class of medications called decarboxylase inhibitors. It works by preventing levodopa from being broken down before it reaches the brain. This allows for a lower dose of levodopa, which causes less nausea and vomiting.

See More Information Regarding Levodopa and Carbidopa

Passion Flower - More Interactions

Passion Flower interacts with 814 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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Parts of this content are provided by the Therapeutic Research Center, LLC.

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.

© 2021 Therapeutic Research Center, LLC

Drug descriptions are provided by MedlinePlus.

Ask A Pharmacist About Your Herbal Questions!

Dr. Brian Staiger, PharmD

In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!

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