The only side effect that I have had with Carbidopa/Levodopa (C/L) is if I take it on an empty stomach. Then I will feel nauseous and also dizzy. It is best to take it with carbohydrates rather than protein. My understanding is that protein interferes with the medication's effectiveness.

I have had nothing but good results with the medication. Here is a link from drugs.com listing many of the medications used to treat PD, https://www.drugs.com/condition/parkinson-s-disease.html. I have personally had good success with Stalevo, which is a combination of C/L plus entacapone. With this medication the amount of C/L is lower and the entacapone helps the medication to last longer.

Regarding the dizziness problem, Vestibular Therapy, is something that has been quite helpful to me. Here is a link from the Cleveland Clinic website with more information about this, https://my.clevelandclinic.org/health/treatments/15298-vestibular-rehabilitation.

Finally, I would highly recommend that your wife be seen by a movement disorder specialist. This is a neurologist with special training and experience in movement disorders such as PD.

If you would like to learn more about PD, I suggest that you explore the Davis Phinney Foundation website. They have numerous videos and information about PD. Here is a link to the website, https://davisphinneyfoundation.org/.

I look forward to hearing from you again and hearing how your wife is doing. Will you continue to post with any questions or concerns?