My thanks go to Benjamin Stecher on PRIG who has pointed us to an important paper that has been published in the NEJM. It attempts to answer the question of whether PwP (People with Parkinson's) should be prescribed levodopa soon after diagnosis or whether its use should be delayed, being saved for later when it is really needed. (Levodopa is the main component in Sinemet, Madopar and Stalevo.)

446 PwP were in the trial. They were placed in one of two cohorts: one took levodopa from the beginning through to 80 weeks; the other took placebo up to 40 weeks and were then moved onto levodopa for the final 40 weeks.

As you might expect, in the first half the levodopa group did better than the placebo group, but in the second half, when both groups were on the same amount of levodopa, there was no statistically significant difference between the two groups.

My take on the result is that it tips the balance to slightly higher doses. If you spend much of the day "off" and if you don't have dyskinesia, you should discuss with your doctor whether more medication is required.

Reference:

[1] "Randomized Delayed-Start Trial of Levodopa in Parkinson’s Disease
Constant V.M. Verschuur, M.D., Sven R. Suwijn, M.D., Judith A. Boel, Ph.D., Bart Post, M.D., Ph.D., et al., for the LEAP Study Group
N Engl J Med 2019; 380:315-324
https://www.nejm.org/doi/full/10.105...kYb_bdtJoa3EQA

John