When carbidopa-levodopa is to be given to patients who are being treated with levodopa, levodopa must be discontinued at least eight hours before therapy with Sinemet is started. In order to reduce adverse reactions, it is necessary to individualize therapy. Carbidopa, an inhibitor of aromatic amino acid decarboxylation, is a white, crystalline compound , slightly soluble in water, with a molecular weight of 244.3. Tablet content is expressed in terms of anhydrous carbidopa, which has a molecular weight of 226.3. Levodopa, an aromatic amino acid , is a white, crystalline compound, slightly soluble in water with a molecular weight of 197.2.
Inactive ingredients are cellulose , magnesium stearate and starch.
The Sinemet CR tablet is a polymeric-based drug delivery system that controls the release of carbidopa and levodopa as it slowly erodes.