For anyone taking medications, it’s important to know possible food-drug interactions.
While there are a multitude of possible drug-drug interactions among Parkinson’s medications, the main food-drug interactions that we need to be aware of are:
- Carbidopa/levodopa with protein
- Bromocriptine (Parlodel®), ropinirole (Requip®), benztropine mesylate (Cogentin®) and amantadine (Symmetrel®) with alcohol
- MAO-B inhibitors (rasagiline, selegiline) with diets or meals very high in tyramine.
Carbidopa/levodopa
Trade names: Sinemet®, Parcopa®, Stalevo®, Rytary™, Duopa™
Among the most common medications for Parkinson’s patients is L-dopa (levodopa), which is often given as a combination with carbidopa. L-dopa is a dopamine precursor that is able to cross the blood-brain barrier (something dopamine itself cannot do). Once it reaches neurons within the brain, it is converted into dopamine by specific enzymes. Carbidopa prevents L-dopa from being converted to dopamine in areas other than the brain. This increases the dose of dopamine you get, and also decreases adverse side effects.
For carbidopa/levodopa to work, it needs to be absorbed by the small intestine. This is where protein can have an adverse effect. L-dopa is an amino acid. Chains of amino acids are what create proteins. While L-dopa itself is not used in proteins, it relies on the same transport machinery as other amino acids to get from the small intestine into your blood stream. Thus, if you have a lot of amino acids while taking L-dopa, much of the L-dopa will remain in your small intestine, and travel through your GI system, never getting to your brain.
To prevent this interaction, take L-dopa 30 minutes before eating, or 2 hours after eating. This gives your small intestine sufficient time to either absorb L-dopa before seeing other amino acids (if taken before eating), or time to absorb the other amino acids prior to seeing L-dopa (if taken after eating)
Bromocriptine, ropinirole, benztropine mesylate, and amantadine
Trade names: Parlodel®, Requip®, Cogentin®, Symmetrel®
For all of these medications, alcohol consumption can increase nervous system side effects. These include dizziness, drowsiness, difficulty concentrating, and impaired thinking and judgement. To limit these side effects, reduce or avoid alcohol consumption completely.
MAO-B inhibitors: Rasagiline, Selegiline
Trade names: Azilect®, Eldepryl®, Carbex®, Zelapar®
Tyramine is a substance found in a multitude of protein-containing foods. Excess quantities of tyramine are normally broken down by MAO-B (an enzyme). When taking an MAO-B inhibitor, ingestion of high levels of tyramine can quickly lead to dangerously high levels of tyramine which can cause a spike in blood pressure requiring prompt medical treatment.
Low levels of tyramine do not have this same effect, so while it’s incredibly important to make sure you do not consume huge amounts of tyramine, you do not have to cut the following foods out completely. Like everything else in life, it’s about moderation.
It’s important to note that as foods which contain tyramine age, the amount of tyramine increases. In addition, tyramine levels can vary among foods based on processing, storage, and preparation. However, cooking will not alter the amount of tyramine in food.
Here’s a (non-comprehensive) list of foods high in tyramine:
- Aged & strong cheeses
- Cured, smoked, and processed meats
- Pickled or fermented foods (e.g. sauerkraut, tofu, pickles)
- Soybeans
- Snow peas, fava beans
- Dried or overripe fruits
- Meat tenderizers
- Yeast extract
- Beer, red wine, sherry, liqueurs
- Some sauces (e.g. soy, shrimp, fish, miso, teriyaki)
If you are taking an MAO-B inhibitor and are unsure of a particular food’s tyramine levels, check before you consume it! In general, fresh foods are low in tyramine.
For more information, look at:
Parkinson Prescription Meds (Parkinson's Disease Foundation)