For many people with a diagnosis of PSP, the journey to a diagnosis was long and confusing. It is common to have initially received a diagnosis of Parkinson’s disease because of the similarities in early symptoms
Carbidopa/levodopa: This is the main medication given to people with Parkinson's, and supplies dopamine to a part of the brain called the substantia nigra, which uses the medication to signal movement in the body. While the movement issues in Parkinson’s are mostly explained by damage in the substantia nigra, that area is only one of many affected areas in PSP. So, while the treatment works well for people with Parkinson’s, its benefit in PSP is unpredictable, usually modest and wears off after only a few years if there is any benefit.
When taking carbidopa/levodopa for PSP, it is recommended to take a standard form of the drug, rather than the controlled- or extended-release version. People with PSP might need a high dose of the drug and should be closely monitored by the healthcare team to watch for signs of cognitive issues or dizziness. People with PSP should be started on a low dose and gradually increase it to test tolerance and effectiveness. If there is no change in symptoms in two weeks, the maximum dose has been reached or there are any negative reactions to the medication, the medication can be tapered off and discontinued.
The most common side effects can include nausea and sleepiness and issues with low blood pressure.
Other Parkinson’s medications and their possible effect on PSP symptoms:
Amantadine: This might have some benefit with gait issues, even if carbidopa/levodopa did not. Its benefit does not usually last more than a few months but can be useful for a short period. For people with PSP the dosage should not exceed 200mg per day because of potential cognitive side effects.
Entacapone (Stalevo): Taken in conjunction with carbidopa/levodopa, entacapone slows down the rate at which dopamine is broken down. This will only have an effect for people whose symptoms show a clear response to carbidopa/levodopa and have a distinct medication wear off between doses.
Dopamine receptor agonists: These drugs have no benefit in PSP beyond what carbidopa/levodopa can do. They are more likely to cause hallucinations, confusion, dizziness and nausea.
Cholinesterase inhibitors: This class of medications has some benefit for cognitive loss in people with Parkinson’s or Alzheimer’s disease. With the possible exception of rivastigmine (Exelon), they have no benefit for people with PSP.
Anticholinergic medications: Pure anticholinergic medications such as amitriptyline, trihexyphenidyl and benztropine might worsen gait and should be avoided in PSP.
Medications that are not commonly used to treat Parkinson's disease, but may help with the Parkinsonism symptoms of PSP are:
Donepezil: A common medication used to help treat the cognitive issues in Alzheimer’s, like memory and confusion. This medication has been found to help with the cognitive function in PSP but does worsen motor symptoms. The medication should be avoided in people with PSP because of increased fall risk and other side effects.
Coenzyme Q-10 (CoQ10): This is an antioxidant that might be showing promise to help with gait and balance. If taken in a non-liposomal formula, the dosage should be between 1,200 – 2,400 mg per day. If taken in a liposomal formulation, about 300mg should be used per day. CoQ10 is not a prescription drug and therefore is not covered by insurance. Always discuss this option with a neurologist before starting the medication.