Monday, January 4, 2010

How different is Stalevo from Sinemet?

Sinemet is actually a combination of levodopa and carbidopa. Levodopa is the active ingredient that enters the brain and gets converted to dopamine once it arrives at its destination. When levodopa was marketed alone (without the carbidopa) a lot of the patients had significant nausea and vomiting. This is because the levodopa that was not absorbed in the gut and was converted to dopamine. In the gut, dopamine cannot be absorbed and therefore it cannot enter the brain beyond its “iron curtain” (called the blood brain barier) (it can only enter if it is in levodopa form). Unfortunately, when outside the brain, dopamine is an irritant. It causes nausea and the vomiting. This is because the one area of the brain (called area postrema) is exposed and stimulated as it is not situated behind the brain’s ‘iron curtain’. Carbidopa blocks the enzyme that coverts levodopa to dopamine in the gut so that more of it gets absorbed and less of it stays in the gut as dopamine. Since carbidopa has been automatically incorporated with levodopa, there has been less nausea experienced by patients. Sin-emet is in fact derived from the latin words, sin (meaning “without”) and emet (meaning “to vomit”). Sinemet therefore means, “without vomiting”. Of course this is not always the case, and some patients actually need extra doses of carbidopa than the one that is built in the sinemet tablet.

It gets even better. Stalevo combines three ingredients: levodopa, carbidopa, plus entcapone. Entacapone blocks another enzyme that breaks down levodopa in the gut. The net result is more levodopa getting absorbed and entering the brain. It is therefore a good drug for those with wearing off as it prolongs the life of levodopa (Hauser 2004).

A double-blind clinical trial known as STRIDE-PD (STalevo Reduction in Dyskinesia Evaluation) to determine if Stalevo is effective in delaying the start of dyskinesias was recently concluded. Unfortunately, it showed that patients who started on stalevo did not have lesser dyskinesias than those who started on sinemet. So for now, unless one is experiencing wearing off symptoms, it might be better to simply use sinemet.
Hubert H. Fernandez

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Posted: Mon Dec 21, 2009 2:40 pm Post subject: Parkinson's symptoms and Nausea


My Mother is not able to walk, bathe, or dress herself due to her Parkinson's. She has been taking 5 doses of Stalevo (125mg) 5 times a day with extra Carbidoba and a Sinemet CR before bedtime. She has a big problem with nausea which we fight continuously. We are staggering the meds/food now, but it does not seem to help too much. Is there a combination of meds that we can try to help alleviate both Parkinson's and the nausea.
Any help is appreciated.

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Dr. Fernandez

Joined: 20 Jan 2007
Posts: 90

Posted: Mon Dec 21, 2009 9:47 pm Post subject:


Actually, i would recommend NOT to stagger food and meds. She should take it with food if she has a lot of nausea.

If this does not work, i would double the dose of carbidopa.

See if those work first, before we do anything else. Talk to her doctor of course.

Hubert H. Fernandez

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