In a statement from Merck Canada Inc., manufacturer of SINEMET^®, the following was noted regarding the production of SINEMET^® CR (controlled release):

"For SINEMET^® CR Merck Canada regrets to announce that after having unsuccessfully pursued alternative supply options, the difficult decision was made to cease the manufacturing, distribution and supply of the product once all current inventories have been exhausted."

Merck Canada Inc. reported ongoing production issues with their current supplier, forcing them to look for an alternate supplier. The company exercised every option to find another supplier who was able to produce the drug based on Health Canada regulations, but were unsuccessful. As a result, SINEMET^® CR will be discontinued in Canada and the U.S..

Please be advised that there are generic forms of SINEMET^® CR on the market. If you are taking SINEMET^® CR and have a prescription, a pharmacist can substitute a generic form for you. Otherwise, it is recommended that you speak with your doctor about alternative options.

The following is the current availability of SINEMET^® CR in the Canadian marketplace:

• SINEMET^® CR 100/25mg - No resupply. Expected remaining inventory to last until September 2019 based on current demand.
• SINEMET^® CR 200/50mg - No resupply. Inventory has already been depleted.

SINEMET^® 

The regular formulation of SINEMET^® is an immediate-release tablet. 

As we previously reported, there have been issues with the production of this formulation as well. Ongoing challenges with their third-party supplier are forcing Merck Canada Inc. to search for an alternate. As a result, shortages of SINEMET^® are still being reported.

The following is the current availability of SINEMET^® (regular formulation) in the Canadian marketplace:

• SINEMET^® 100/25mg - Stock depleted with anticipated resupply date of July 2020.
• SINEMET^® 250/25mg - Stock expected to deplete by December 2019 with the anticipated resupply date of July 2020.

If you are taking carbidopa-levodopa to manage your Parkinson’s symptoms, it is advised that you check your current prescription. If you have been prescribed a SINEMET^® product that is in shortage or discontinued, your neurologist or prescriber is in the best position to recommend alternatives and/or adjustments to your current medication regimen.

For more information, view the statement from Merck Canada Inc. 

Update (Thursday, April 18, 2019):
This article has been updated to reflect recent information obtained from representatives of Merck Canada Inc. We had previously misreported that Merck Canada Inc. had located a new supplier for the regular formulation of SINEMET^®, and had applied to Health Canada for approval to use this supplier. There is, in fact, no such application on file with Health Canada, and Merck Canada Inc. continues to search for a new supplier to mitigate shortages.

Additionally, we reported that the regular, immediate release formulation of SINEMET^® was more commonly used than SINEMET^® CR (controlled release). This information was generalized from reports gathered from our community, which may not be representative of all individuals using these drugs. Based on their distribution data, Merck Canada Inc. claims that SINEMET^® CR is, in fact, more commonly used than the regular formulation.

We apologize for any confusion this may have caused. For further information on anticipated drug shortages, and expected resupply or supply depletion dates, please visit drugshortagescanada.ca.