Will a COMT inhibitor help my motor fluctuations?

Question

Hi, Doctor.

I am a 58-year-old male with early-stage Parkinson’s disease. I have been taking Levodopa-Carbidopa for the last two years but recently noticed that I am getting wearing-off symptoms before my next dose. My neurologist mentioned adding a Catechol-O-methyltransferase (COMT) inhibitor.

Can adding a COMT inhibitor help smooth out my motor fluctuations?
And are there any major side effects I should know about?

Kindly help.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and can understand your concern.

What you are describing as “wearing off” is a very common phenomenon after a few years of Levodopa-Carbidopa use. This means that the benefit from each dose wears off more quickly and symptoms such as tremor, stiffness or slowness return.

COMT inhibitors (catechol-o-methyltransferase inhibitors) such as Entacapone, Opicapone or Tolcapone slow the breakdown of Levodopa in the body, which means that more Levodopa can reach the brain and that the effect of each dose lasts longer. This may help to smooth out the motor fluctuations and reduce the “off” periods between doses.

COMT inhibitors are usually taken with every dose of levodopa, except for Opicapone, which is taken once a day. This often helps to control symptoms without greatly increasing the total levodopa dose.

Side effects include mild diarrhea or nausea, particularly at the beginning of treatment, and harmless orange urine. Sometimes when levodopa starts to work too well, you might have more vivid dreams or dyskinesias (involuntary movements). Your neurologist can adjust the dose of levodopa as needed to find that sweet spot.

There is a rare potential for tolcapone to affect the liver and so needs regular monitoring of liver function. In this respect, Entacapone and Opicapone are generally considered safer.

I hope this helps.

Thank you and take care.

Regards.