Why Aren’t My Parkinson’s Medications Working? Could It Be What I’m Eating?

One of my students said he heard at a conference that eating protein interferes with Sinemet, and that this made him confused. “I’ve been on this drug for months and no one ever told me about this. I was told to take Sinemet with food so it doesn’t upset my stomach, so I’ve been eating it with a beef sandwich.” Then another student said, “I have heard three different time frames regarding when to eat protein.”

So I decided to call around and see what pharmacists had to say. While I received several different versions of the rules, there was an underlying reasoning which was consistent.

Levodopa/Carbidopa or Benserazide (also known as Sinemet, Madopar, and other names) is a common medication used to treat the symptoms of Parkinson’s disease. However, there are some barriers to absorption of regular (quick-release) Sinemet/Madopar by the body, and here’s why:

• If you take Sinemet with a meal, or just after, it may take a long time for the drug to be absorbed. Your stomach empties in 1-3 hours, and if Sinemet is mixed with food, it takes the same amount of time to clear the stomach as the food does. High fat meals take longer to empty the stomach.
• Protein in food must be broken down into amino acids then travel across the intestinal wall to get into the blood. Then they must cross the blood-brain barrier to enter the brain.
• Sinemet must also travel across the intestinal wall and the blood-brain barrier using exactly the same “carrier system” as the amino acids.
• When you eat protein, the amino acids use up all the “carriers”, so the Sinemet must wait until the carriers are free again to cross over into the bloodstream. The same thing happens when Sinemet tries to get to the brain. Again, the amino acids clog all the “carriers” and the Sinemet can’t get through to the brain. Therefore, a meal high in protein combined with Sinemet can seriously interfere with your medication’s absorption, particularly at the level of the brain receptors.
• It’s best to take Sinemet 30 to 60 minutes before eating a meal. This allows the Sinemet to be quickly absorbed before the food can interfere. You should then wait 2 hours after eating to take your pill again.
• Many people experience nausea with Sinemet, especially at first. The solution: Take the Sinemet along with foods that don’t contain protein or high fat. Ginger tea or ginger ale is a good choice for many people, because it “settles the stomach.” Crackers are very low protein and can help too.
• For many people dairy blocks levodopa to a greater extent than other protein-rich foods. To get better results from your Sinemet, use high-protein foods moderately, along with large helpings of fruits, vegetables, and grains. Eat a small portion (3-4 ounces) of meat, poultry, fish, or eggs, accompanied by fruit, vegetables, and grains.

Resources:

Parkinson’s Foundation
Web MD