Also indexed as: Dopar, L-dopa, Larodopa
Levodopa is the precursor required by the brain to produce dopamine, a neurotransmitter
(chemical messenger in the nervous system). People with Parkinson’s disease have depleted levels of
dopamine. Levodopa is used to increase dopamine in the brain, which reduces the symptoms of
Parkinson’s disease. Levodopa is broken down by the body before it reaches the brain. To
avoid this, levodopa is used with carbidopa, a
drug that protects levodopa from breakdown. Levodopa is available alone or in a combination
product.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
 May Be Beneficial: Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them. |
Vitamin B6
|
| Side effect reduction/prevention |
None known
|
| Supportive interaction |
None known
|
| Reduced drug
absorption/bioavailability |
None known
|
| Adverse interaction |
None known
|
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
evidence.
Interactions with Dietary Supplements
Vitamin
B6
Levodopa is broken down in the body by a process requiring vitamin B6. Breakdown may deplete
available vitamin B6. Carbidopa blocks
levodopa breakdown and prevents vitamin B6 depletion. People taking levodopa/carbidopa (Sinemet®), or levodopa plus
carbidopa (Lodosyn®) have no risk for levodopa-induced vitamin B6 deficiency; it is not a
problem for people to supplement vitamin B6 while taking Sinemet.
For people taking levodopa alone, small amounts of vitamin B6 (5–10 mg per day) may
prevent levodopa-induced vitamin B6 deficiency.1 Amounts of vitamin B6 slightly
higher than those required to replace depleted levels, may reduce the effectiveness of
levodopa therapy and should not be taken.2
Interactions with Foods and Other Compounds
Food
Food, especially foods high in protein, compete with levodopa for absorption. However,
levodopa may be taken with food to avoid stomach upset.3 It is important to take
levodopa at the same time every day, always with or always without food. People with questions
about levodopa and food should ask their prescribing doctor or pharmacist. Taking
sustained-release Sinemet® CR with food
may increase blood levels of levodopa.4 It is important to take Sinemet® CR at
the same time every day, always with or always without food. People with questions about
Sinemet® CR and food should ask their prescribing doctor or pharmacist.
References:1. Long JW. The Essential Guide to Prescription Drugs 1992. New
York: Harper Perennial, 1991.
2. Trovato A et al. Drug-nutrient interactions. Am Family Phys
1991;44:1651–8.
3. Threlkeld DS, ed. Central Nervous System Drugs, Antiparkinson Agents,
Levodopa. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Sep 1991, 289p–290a.
4. Threlkeld DS, ed. Central Nervous System Drugs, Antiparkinson Agents,
Levodopa. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Sep 1991, 289p–290a.