Switching from levodopa to an extended release levodopa for patients with fluctuating Parkinson’s disease

This study investigated the effectiveness and the dosing of switching from standard levodopa to the new carbidopa/levodopa extended release capsule (C/L ERC; Rytary) to treat Parkinson’s disease. Researchers suggested that C/L ERC was generally well tolerated and preferred by many patients.

Parkinson’s disease (PD) is the second most common age-related disorder. This disease affects the brain cells responsible for body movement and function. The standard treatment for PD is levodopa-based therapy which is associated with negative side effects if used for a long period.

Over time, patients start to experience changes in their symptoms, which is called fluctuating disease. These symptoms may be coming back in the period between taking medication. Prior studies showed that C/L ERC is associated with improved treatment of fluctuating PD. However, levodopa dosing in C/L ERC is very different from the conventional treatment and no adequate dosage is known.

The study included information about 80 patients with PD treated with levodopa preparations. All patients were given C/L ERC. Results in terms of effectiveness, toxicity, and dosing were analyzed.

After an average follow-up of 119 days, 68 patients took at least one dose, of which 43 remained on C/L ERC. The average C/L ERC dose used during the whole study was 308-387 milligrams, 3-5 times a day.

Improved outcomes were seen in 27 (39.7%) patients. Dyskinesia (uncontrollable body movements) was also improved. Side effects included hallucinations, dyskinesia, increased dreams, and nausea.

This study showed that C/L ERC was generally well tolerated and preferred by many patients. The levodopa daily dosage conversion ratio is from 2 to 1.

This study did not separate the patients who stopped the treatment due to drug cost.