Carbidopa/levodopa

Carbidopa/levodopa, also known as levocarb and co-careldopa, is the combination of the two medications carbidopa and levodopa.^[6] It is primarily used to manage the symptoms of Parkinson's disease, but it does not slow down the disease or stop it from getting worse.^[6] It is taken by mouth.^[6] It can take two to three weeks of treatment before benefits are seen.^[7] Each dose then begins working in about ten minutes to two hours with a duration of effect of about five hours.^[7][8][9]

Common side effects include movement problems and nausea.^[6] More serious side effects include depression, low blood pressure with standing, sudden onset of sleepiness, psychosis, and increased risk-taking behavior.^[6][10] Carbidopa prevents the breakdown of levodopa outside the brain.^[10] In the brain, levodopa is broken down into dopamine, its active form.^[10] Carbidopa also helps prevent some of the nausea which levodopa causes.^[11]

It is on the World Health Organization's List of Essential Medicines.^[12] It is available as a generic medication.^[10] In 2022, it was the 278th most commonly prescribed medication in the United States, with more than 700,000 prescriptions.^[13][14]