levodopa magnesium oxide
Applies to: Dopar (levodopa), magnesium oxide

Antacids and some oral aluminum, calcium, or magnesium containing preparations may increase the absorption of levodopa. The mechanisms may be related to increased gastric pH and/or decreased gastric emptying time, resulting in less gastric degradation of levodopa and more levodopa absorption from the small intestine. This effect may be beneficial in some patients, but also difficult to predict and monitor. For most patients, this interaction is not clinically significant and no specific intervention would be required. Dosing intervals could be spaced by at least 2 hours if it is preferred to avoid this interaction.

References
Rivera-Calimlin L, Dujovne CA, Morgan JP, Lasagna L, Bianchine JR (1970) “L-dopa treatment failure: explanation and correction.” Br Med J, 4, p. 93-4
Rivera-Calimlim L, Dujovne CA, Morgan JP, Lasagna L, Bianchine JR (1971) “Absorption and metabolism of L-dopa by the human stomach.” Eur J Clin Invest, 1, p. 313-20
Fermaglich J, O’Dougherty DS (1972) “Effect of gastric motility on levodopa.” Dis Nerv Syst, 33, p. 624-5