Sinemet Plus and other Drugs - Does it matter to you who makes it?

My local Boots usually dispense the yellow oval Sinemet Plus 100/25 produced by Quadrant (in Bolton) I've had no issues with them other than the central label on the foil packaging hinders removal of the tablets, when I'm OFF.

Boots have occasionally issued the pale round tablets from Merck Sharp & Dohme. I find these are much easier to get out of the foil pack.

I had read somewhere on the forum that PwP have varying reactions to who produces their Sinemet Plus so I decided to try a week using only these to test this out. I also wanted a more robust reason for asking Boots to supply the MSD ones, other than being easier to get out of the foil.

After just four days (20 tablets in all) it was like I hadn't taken any Sinemet.

I switched back to the yellow ovals and I'm back on track again.

Anyone else found who produces their Sinemet Plus affects how effective it is and potentially which side effects you get?

Also wondering if this applies to other drugs and whether in some (maybe not so small) way contributes to the variety and complexity of our prescriptions.  Are prescription changes being triggered by who produces the drugs rather than just the progression of our underlying PD symptoms?


Good question.

I don't know what the situation is in the UK, but in the US the FDA set the rules for generic drugs. For a brief explanation see [1].

Generic drugs do NOT need to be literal copies of brand drugs. They do not need to be tested for effectiveness.  They are required to show "bioequivalence". This is based on pharmacokinetic properties such as CMAX (maximum concentration) and AUC (area under curve). For levodopa this involves test subjects taking the drug and then having blood samples taken at regular intervals over a few hours.

Now for the interesting bit. The 90% confidence interval for the AUC is only required to be within 80% and 125% of the original drug. (Note: this is not the same as saying that the dose may vary from 80% to 125% of the reference dose. The rule which deals with confidence intervals is more strict than that. But, it could, for instance, allow something that was 10% more or 10% less.)

A generic pill can have different fillers and binders, which may affect people differently.

Add in a bit of placebo effect, and the sensitivity of PD to the actual dose, as opposed to the nominal dose, and you can get large variations in symptom control.





I have been taking the oval sinimet plus and like you very hard to get out packaging without breaking.Now today pharmacy has given me round ones and all day being off. Dont know if it is to do with tablet.But feel as though I have not had my medicaion.

Joint Thank you for the detail. Added to the varying dosage there's also the coating to get it absorbed after the stomach. I suspect the round tablets require different timings red food to stop it being swamped by protein. Glasgow girl That was my experience as well but being a stubborn oldish got I stuck at it for four days before I could take no more. The effect of going back to the oval was like a switch being flicked after an hour. I have picked off the central label and found that helps with getting them ou..

I have said this so many times on this forum. Generic pills may not be as effective as they may contain the original medication BUT also goodness know what else as a filler.See my posts on Requip V Ropinirole.

Even my mediation for IBS, the  film coated  tablet does not work as well as the  uncoated one.  My thyroid tablets are from all and sundry providers and I CAN tell the  difference in effectiveness.

Generic tablets are a copy and not the original drug which involved huge expense to the pharmacuetical company  to develop. Once the licence on that drug has expired, any T, D or Harry can copy it, more and more from countries in Europe and beyond, I have found.




I have also experienced the generic drugs, my usual brand of Ropinirole was replaced by  another brand i.e.from Ralnea to Eppinex, I was told this change would not effect me, but it sure did!! I was on the phone to GP straight away virtually demanding my original brand of meds back again, so we don't have to accept second class drugs!


Hi Sheila


was lovely to meet you and Brian. Enjoyed your company.

I spoke to my pharmacy  at my local chemist about the different types of sinimet plus and she said they have to make it the exact i said i had felt a difference,And she said it must just  be my imagination.


Hope you got home ok. Speak soon. Xx  The meet up was great  and emotional thanks for making it happen. Xxx

babswood - Just found this old posting from May '17 and wish we could do York trip all over again…:thinking::disappointed:

Take care - Sheila