The fluctuations in response to
levodopa experienced by some patients may be due to the timing of their meals and the type of diet, particularly the protein content. The effects of
levodopa can be reduced by the amino acid methionine, and the blood levels of
levodopa can be reduced by the amino acid tryptophan.
If problems occur, a change in the pattern of drug and food
administration on a trial-and-error basis may be helpful. Multiple small doses of
levodopa and spreading out the intake of
proteins may also diminish the effects of these interactions. Diets that conform to the recommended daily allowance of protein (said to be 800 mg/kg in one report) are reported to reduce this adverse drug-food interaction.