The Parkinson’s Association of Ireland (PAI) and Move4Parkinson’s have been made aware by Merck Sharp & Dohme Limited (MSD) that there is currently a supply issue with some of their Sinemet products in Ireland and other countries.

MSD has informed us that this has been caused by current manufacturing capacity constraints, and that the following Sinemet products will be unavailable in Ireland:

* Sinemet Plus® (25/100) 10X10 tablet

* Sinemet®25/250 10X10 tablets

Sinemet plus 25/100mg tablets and Sinemet 25/250mg tablets are now unavailable from wholesale providers, although some pharmacists still hold supplies (as of 01 October 2018). It is expected that the supply issues will continue until the first quarter (January to March) of next year.

We are aware this is a constantly changing situation. We are in regular contact with MSD and will update you immediately if any change happens.


If you are currently taking Sinemet, there is a chance that your Pharmacist will be unable to give you your prescription. It may be possible for you to take an alternative combination of Sinemet tablets to meet your needs – however this should be done under the guidance of your GP or pharmacist. There are also generic versions of Co-careldopa, the active ingredient in Sinemet, available in a range of strengths. Your GP or Pharmacist will discuss these with you and should be able to offer you a suitable alternative.

If you have any questions or concerns regarding your medication or if you are unable to obtain Sinemet products, you can discuss this with your GP, Consultant, Pharmacist or Parkinson’s nurse. You can also contact the PAI helpline on Freephone 1800 359 359

You can also check for updates from MSD on the availability of Sinemet in Ireland here -

Frequently Asked Questions

We have compiled the FAQ below to assist those affected in understanding the impacts of the Sinemet shortages and we will continue to update these moving forward. Should you have concerns regarding this issue we recommend speaking directly with your GP, alternatively you can contact the PAI helpline on Freephone 1800 359 359

When will the medicines shortage start? How long will it last?

The shortage of Sinemet 25/250mg and Sinemet plus 25/100mg tablets has already impacted wholesale providers, any pharmacies which do not have stocks of this tablet will be unable to secure further supplies until the first quarter of next year.

Information supplied by MSD suggests a normal return to medicines availability in Quarter 1 (between January and March) 2019.

Should I do anything different when filling my prescription?

We recommend that over the next few months you fill your Sinemet® prescription at least a week before it runs out to allow a satisfactory alternative to be sourced. Please be aware that you may need to speak to your GP to change your prescription for an alternative - you should allow enough time to do this rather than waiting until you are low on medication supplies.

What alternatives are available?

As things currently stand, the medication substitution options for patients established on Sinemet products are:

* Multiple dosings of Sinemet® 12.5/50 for Sinemet® 25/100

* Substituting Sinemet® 10/100 for Sinemet® 25/100(the ‘10’ rather than ‘25’ of carbidopa may cause some nausea in some patients)

* Substituting Sinemet® CR 50/200 for Sinemet®25/250

* Generic co-careldopa at equivalent levodopa dose

* Madopar® – co-beneldopa – capsules at equivalent levodopa dose

* Stalevo® – likely at equivalent levodopa dose or ‘consider small dose reduction’

Note that switching to any of the above will require you to consult with your GP and/ or pharmacist – you should not adjust your medications without consulting your GP, pharmacist or Parkinson’s nurse.

Will I notice any difference on the new medication?

The basic active agent in Sinemet® and the alternatives above is levodopa so you should be optimistic that your Parkinson’s can be controlled close to current levels with the Sinemet® alternatives. In the event that your PD control worsens then other therapy options can be explored directly with your prescriber/specialist.

How do I get more information?

Your local pharmacist can help around what alternatives are readily available and to ensure that they don’t interact with other medications you may be on.

Your GP can help with the prescription of alternatives.

Your Parkinson’s Nurse specialist and PD doctor can also advise on alternatives.

You can also contact the PAI helpline on Freephone 1800 359 359

Finally, you can check for updates from MSD on the availability of Sinemet in Ireland here -

I have heard about shortages of other doses of Sinemet in the UK and other countries – is Ireland affected by those?

Each country is experiencing different shortages of Sinemet products, so you should be guided by the information on shortages provided by MSD Ireland on their website (, which we will also replicate on the PAI and Move4Parkinson’s websites.

The shortages in each country will be different – and we will keep you updated on the Ireland specific issues

Will other doses of Sinemet be affected?

At this point MSD are unable to provide confirmation of whether other doses of Sinemet will be affected. They have however committed to regularly updating our organisations on the status of shortages in any doses of Sinemet.

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