Is It Safe To Take Ashwagandha With Carbidopa/Levodopa?

Answer

Thanks for reaching out! I am more than happy to provide some insight for you.

It looks like you have two questions in your submission to us that I will answer separately:

• Is ashwagandha safe to take with carbidopa/levodopa (generic for Sinemet)?
• Why would your doctor prescribe IR and ER carbidopa to be taken at the same time?

Ashwagandha With Carbidopa/Levodopa

I can understand wanting to use ashwagandha to help with the anxiety symptoms your mother is experiencing as there have been several studies showing it may be beneficial in this regard. The good news here is that there no known interaction between ashwagandha and carbidopa/levodopa. 

Ashwagandha is not known to affect any aspect of how carbidopa/levodopa is absorbed, metabolized, or functions in the body.

Now, it must be noted that there have been no studies that have specifically tested ashwagandha for interactions with carbidopa/levodopa, so we could just be missing some data, but there is no evidence to suggest an interaction either.

In fact, very small clinical studies have shown that some products that contain ashwagandha may improve some symptoms of Parkinson's Disease, but more research is definitely needed in this area.

It is important to let your doctor (or your mother's in this case) know about all the medications you are taking, including ashwagandha if that is added, so you can be appropriately monitored.

Carbidopa/Levodopa Immediate-Release & Extended-Release At The Same Time?

The mainstay of Parkinson's disease treatment is the use of carbidopa and levodopa.

Levodopa, sometimes referred to as L-dopa, is a metabolic precursor to dopamine. Levodopa enters the CNS (central nervous system) where it is converted to the neurotransmitter dopamine, which is what helps control many of the symptoms of Parkinson's Disease. Levodopa is used in medication as opposed to dopamine because levodopa can cross the 'blood-brain barrier' and enter the CNS while dopamine cannot.

Carbidopa is a 'decarboxylase inhibitor' that blocks the systemic conversion of levodopa to dopamine before it reaches the CNS. This increases how much levodopa can enter the central nervous system and substantially lowers the dose of levodopa needed to produce a clinical effect.

All of this put more simply, levodopa is a medication used to help control the symptoms of Parkinson's disease and converts into dopamine in the brain. Carbidopa is a medication that helps levodopa work better by preventing its breakdown before it reaches the brain, this way it needs less dosage.

Carbidopa/levodopa is available in many different forms, including immediate-release formulations and extended-release formulations.

As a general rule of thumb, immediate-release formulations are preferred in many medical guidelines as studies have not definitively shown that extended-release formulations provide any additional benefit. In fact, extended-release (sometimes referred to as 'controlled-release') may have some more negatives with it, including less predictable absorption and effects.

Clinical guidelines for Parkinson's Disease, published by AAFP (American Academy of Family Physicians), state the following:

Sustained-release preparations add no benefit for motor complications compared with immediate-release preparations

Another clinical guideline, published in the journal 'Neurology', has a similar statement:

Although there is no evidence to support superiority of one formulation of levodopa over another, there are other reasons to favor initiating treatment with IR levodopa. CR levodopa has lower bioavailability and less predictable symptom relief compared to IR levodopa, which may necessitate treatment discontinuation in later stages of the disease due to dose failures. Whereas levodopa/carbidopa/entacapone can be helpful for patients who experience end-of-dose wearing-off, this is not a usual clinical feature in early PD. IR levodopa is less costly than other levodopa formulations

In regard to taking immediate and extended-release carbidopa/levodopa at the same time, as your question asks, no clinical guidelines for treating Parkinson's disease touch on this that I could find. Nevertheless, I have certainly seen this being done before and there is actually a carbidopa/levodopa product that contains both IR and ER forms of carbidopa/levodopa in a single capsule.

The thought process behind combining immediate-release and extended-release carbidopa/levodopa is that the combination could lead to symptoms being better controlled overall in the form of reduced 'off' time over the course of a day and an immediate-release formulation can still be taken throughout the day (typically low doses, such as 1/2 tablet) at 4 to 8 hours intervals if more levodopa is needed.

As mentioned, there is a drug that contains both IR and ER carbidopa/levodopa and that drug is Rytary, so it seems like the doctor here is essentially trying to recreate it.

There certainly could be benefits to dosing how your doctor is recommending versus using Rytary, such as more flexibility in dosing, and the fact that Rytary is only available as a brand-name medication, and is very expensive.

Final Words

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