I wonder whether there is agreement amongst us in the forum on how best to medicate for the motor symptoms of PD.

When it comes to Parkinson's, it is common to say that we are all different. This is true. But what strikes me is how similar are the dosing regimes that people have. At its simplest, it seems to me that dopamine replacement therapy (DRT) comes down to these principles:

1. Many PwP have health needs in addition to motor problems, e.g. anxiety. Medications for these needs are not covered here.

2. DRT is not the only therapy to deal with motor problems: exercise and DBS can have good results, but usually they are not enough in themselves to avoid DRT all together. These approaches are not considered here.

3. Even late into the disease PwP are continuing to produce and store some of the dopamine they require. These factors should be estimated.

4. The aim of DRT is to keep PwP mobile for as long as possible.

5. There is no conclusive evidence that presently available drugs can slow the progression of the disease. So, DRT is for symptom relief only.

6. There is no benefit from undermedicating, except in order to avoid overmedicating.

7. Overmedicating should be avoided. It can lead to dyskinesia, impulse control problems, psychosis.

8. The underlying cause of the disease affects a person in many ways, but as far as DRT is concerned it leaves us with an inability to produce enough dopamine AND/OR a reduced ability to store it.

9. The disease is progressive, so dosing will typically increase with time.

10. DRT dugs, even when of a different type have an additive effect. (An exception is rasagiline where beyond 1mg it usually has no improved effect.)

11. To estimate the combined effect of two or more doses, three factors are required for each dose: the levodopa equivalent dose (LED), the time it is taken and the duration of its effectiveness.

12. The reason for taking different combinations of DRT drugs is two-fold. First, some PwP are unable to stomach some DRT drugs. Second, is to make use of the differing properties of the drugs so as to smooth out the graph of combined LEDs over time. A DRT based on immediate release levodopa is, unless advanced control features are introduced, likely to lead to large variations during the day, Whereas a DRT based exclusively on drugs which are long lasting, such as rasagiline or ropinirole controlled release, is unlikely to match changing needs during the day.

13. The time it takes a dose taken by mouth to take effect is contingent on protein in the diet, constipation and gastric emptying. In bad cases a whole dose can be "lost".

14. Doses should not be increased rapidly. They should be increased over a period of a few weeks until optimum levels are found.

15. Doses should not be reduced rapidly because of the danger of neuroleptic malignant syndrome.

John