Half Sinemet CR is a controlled release version - the effect is spread out more evenly and over a longer period of time.
Sinemet Plus is NOT a controlled version. It has effect more quickly and for a shorter period of time.
Even they probably don't know why they swap the 100/25 and 25/100 around !
The following is an up to date summary of the medical literature we previously prepared :
Pharmacology : Sinemet CR is a sustained release version of Sinemet. Sinemet CR is intendedd to release the medicine slowly and continuously over several hours in order to help provide steady blood levels of L-dopa throughout the day. The capsules must be swallowed whole and not broken or chewed in order to avoid damaging the modified release action. Treatment with Sinemet CR instead of Sinemet or L-dopa resulted in a significant increase in total L-dopa dose.
Efficacy : Of those people that changed from L-dopa to Sinemet CR, there was significant improvement in symptoms. Most people changing from Sinemet to Sinemet CR improved their symptoms. However, after 5 years, Sinemet and Sinemet CR had similar effects. Sinemet CR was preferred to Sinemet and L-dopa by a clear majority of patients. Sinemet CR and Madopar CR differed little in their effect. Patients improved gradually whilst taking Sinemet CR, usually taking over a week to achieve maximum response. After ceasing chronic use of Sinemet CR it took about a week for the beneficial effects to wear off.
Adverse effects : Of those people that changed from L-dopa to Sinemet CR, two thirds experienced motor complications and one third had a stable motor response. Adverse effects were usually mild or moderate. The number of drug-related adverse events was similar in the two groups. Some people ceased the use of Sinemet CR because of adverse events. The severity of dyskinesia increased when changing from L-dopa. The most common drug-related effect of Sinemet CR was nausea. Other drug related effects were dizziness, insomnia, abdominal pain, dyskinesia, headache and depression. Drug related withdrawals were less than 10% of all patients, primarily due to nervous or psychiatric complaints. The number of drug related adverse experiences were similar with Sinemet and Sinemet CR.