carbidopa
Carbidopa (Lodosyn) is taken with Sinemet (carbidopa / levodopa) or levodopa alone to treat adults with symptoms of Parkinson's disease (PD), like shakiness and slowed movement. The medication belongs to the decarboxylase inhibitor class and it works by helping levodopa better travel into your brain so it can relieve your symptoms. This might allow some people to take a lower dose of levodopa, which can lower some of its side effects. Side effects include fatigue, a drop in blood pressure, changes in urination, and weight changes.
What is Carbidopa (Lodosyn)?
What is Carbidopa (Lodosyn) used for?
When taken together with levodopa or Sinemet (carbidopa / levodopa):
How Carbidopa (Lodosyn) works
Carbidopa (Lodosyn) is a decarboxylase inhibitor. It works by helping more levodopa reach your brain. There, levodopa turns into dopamine, a chemical that eases symptoms of Parkinson's disease (PD).
Without carbidopa (Lodosyn), much of levodopa breaks down before reaching your brain, requiring a higher dose of levodopa which can cause more side effects. Carbidopa (Lodosyn) prevents this breakdown, allowing a lower dose of levodopa with fewer side effects. But it doesn't work when taken alone.
Drug Facts
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What are the side effects of Carbidopa (Lodosyn)?
Common Side Effects
- Involuntary movements (dyskinesia or dystonia)
- Nausea
Other Side Effects
- Psychotic behavior (e.g., delusions, hallucinations, paranoia)
- Depression with or without suicidal behavior
- Dementia
- Seizures
- Dark-colored saliva, sweat, or urine
Serious Side Effects
- Neuroleptic malignant syndrome (NMS): Confusion, very high fevers, irregular pulse, sweating, muscle stiffness, changes in blood pressure
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Falling asleep during daily activities
- Mood and behavior changes—anxiety, nervousness, confusion, hallucinations, irritability, hostility, thoughts of suicide or self-harm, worsening mood, feelings of depression
- New or worsening uncontrolled and repetitive movements of the face, mouth, or upper body
- Sudden eye pain or change in vision such as blurry vision, seeing halos around lights, vision loss
- Urges to engage in impulsive behaviors such as gambling, binge eating, sexual activity, or shopping in ways that are unusual for you
Pros and cons of Carbidopa (Lodosyn)
Pros
Helps levodopa relieve your Parkinson's symptoms
Might allow some people to take a lower dose of levodopa, which can ease side effects like nausea and vomiting
Can split the tablet in half as needed
Available in a lower-cost generic form
Cons
Doesn't work when used alone and must be taken with levodopa
Might need to be taken multiple times per day
Can cause psychotic behavior and strong urges
Can make you fall asleep suddenly with or without warning
Pharmacist tips for Carbidopa (Lodosyn)
Carbidopa (Lodosyn) doesn't work when it's taken by itself. It should be taken with other Parkinson's medications that contain levodopa (e.g., Sinemet (carbidopa / levodopa)).
Carbidopa (Lodosyn) can be taken with food to lower the risk of stomach upset. Avoid eating protein-rich foods, such as meat, milk, cheese, or nuts, with the medication, because they can affect how fast and how much levodopa gets into your body. This can affect how well the medication works.
Carbidopa (Lodosyn) can make you very sleepy or it can make you fall asleep suddenly with or without warning. Don't drive or do anything that requires concentration until you know how the medication makes you feel.
Although it's harmless, carbidopa (Lodosyn) can make your saliva, sweat, and urine darken in color (e.g., red, brown, black). These dark-colored bodily fluids can stain your clothing.
You might have more difficulty controlling your body's movements (dyskinesia) after starting carbidopa (Lodosyn). If this becomes bothersome, let your provider know, so they can prescribe a lower dose of levodopa.
Iron and other medications, vitamins, and supplements containing iron can interfere with carbidopa (Lodosyn) and affect how much of the medication gets into your body. Avoid taking carbidopa (Lodosyn) at the same time as iron.
Frequently asked questions about Carbidopa (Lodosyn)
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What are the risks and warnings for Carbidopa (Lodosyn)?
Carbidopa (Lodosyn) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Sleepiness or falling asleep during activities
Risk factors: History of drowsiness | History of sleep problems | Taking sedatives or medications that make you drowsy
Carbidopa (Lodosyn), medications containing carbidopa and levodopa, and medications that raise your dopamine levels can make you fall asleep out of nowhere, even if you don't feel sleepy. Because of this risk, avoid driving or doing things that require you to focus until you know how this medication affects you, especially if you normally feel sleepy or if you've fallen asleep suddenly in the past. Let your provider know if you experience any problems with sleepiness, they might have you stop the medication.
High fevers and confusion (from levodopa)
Although rare, stopping or lowering your dose of levodopa too quickly can cause side effects similar to those of neuroleptic malignant syndrome (NMS). Because carbidopa (Lodosyn) is often taken with levodopa or Sinemet (carbidopa / levodopa), you'll need to be aware of this side effect.
NMS is a life-threatening condition caused by certain mental health medications. It can cause very high fevers, confusion, irregular pulse, sweating, muscle stiffness, and changes in blood pressure. But luckily NMS is treatable if it's recognized early. Don't stop taking or lower the dose of any medication containing levodopa without talking to your provider, so they can instruct you on how to stop the medication safely.
Impulsive behavior
Carbidopa (Lodosyn) and other Parkinson's disease medications can cause changes in people's behavior, including strong sexual or gambling urges, urges to spend a lot of money, and binge eating. These medications can also make it hard to control these urges. If these urges start to have a negative impact on your life, let your provider know. You might not know you have these urges while taking carbidopa (Lodosyn), so your provider might ask you if you've recently had these behaviors at your next visit. Lowering your dose or stopping the medication might stop these urges.
Hallucinations and changes in behavior and thoughts
Risk factors: History of certain mental health conditions
Carbidopa (Lodosyn) and medications that raise your dopamine levels can cause hallucinations and changes in behavior and thinking, such as paranoia, delusions, confusion, aggressive behavior, and less awareness of your surroundings. Generally, these symptoms occur shortly after you start taking these medications and they can stop once your dose of levodopa is lowered. Certain mental health medications can worsen your Parkinson's disease and might affect how well carbidopa (Lodosyn) works.
Depression and suicidal thoughts and behavior
Risk factors: History of depression
People taking Carbidopa (Lodosyn) and other carbidopa/levodopa medications have developed depression, sometimes with suicidal thoughts and behavior. If you or anyone around you notices any signs of depression or suicidal thoughts or behavior, get medical help right away.
Skin cancer
People with Parkinson's disease have a higher risk of skin cancer. It's important to regularly check if you have any new or unusual growths on your skin or a change in one of your moles. Let your provider know if you notice any of these changes on your skin. Your provider might recommend occasional skin examinations.
Carbidopa (Lodosyn) dosage forms
| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 25mg | 90 tablets | $71.42 | $0.79 |
Typical dosing for Carbidopa (Lodosyn)
Carbidopa (Lodosyn) should be taken together with medications that contain levodopa, such as levodopa alone or Sinemet (carbidopa / levodopa).
The dose depends on how much carbidopa/levodopa you're taking and what your response to carbidopa (Lodosyn) is.
People already taking Sinemet (carbidopa / levodopa): The typical dose of additional carbidopa (Lodosyn) is 25 mg by mouth with your first dose of carbidopa/levodopa of the day. If needed, you can take an additional 12.5 mg to 25 mg with each of your following doses of carbidopa/levodopa.
People taking carbidopa and levodopa separately: The typical dose of carbidopa (Lodosyn) is 25 mg by mouth 3 or 4 times a day with each dose of your levodopa.
Don't take more than a total of 200 mg of carbidopa per day (from both carbidopa (Lodosyn) and carbidopa/levodopa medications).
How much does Carbidopa (Lodosyn) cost?
Carbidopa (Lodosyn) contraindications
Don't take levodopa or any medications containing carbidopa/levodopa if these situations apply:
Take mental health medications called nonselective monoamine oxidase inhibitors (MAOIs)
Narrow-angle glaucoma
What are alternatives to Carbidopa (Lodosyn)?
When taken together with levodopa or Sinemet (carbidopa / levodopa):
Parkinson's disease (PD)
Parkinsonism (conditions that cause people to have signs and symptoms of PD, including slowness, stiffness, shakiness, and imbalance)
Carbidopa (Lodosyn) images
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References
Best studies we foundGhandi, K. R., et al. (2023). Levodopa (L-dopa). StatPearls.
Parkinson’s Foundation. (n.d.). Dyskinesia.
Parkinson’s Foundation. (n.d.). Dystonia.
Parkinson’s Foundation. (n.d.). Understanding Parkinsonism.
Zydus Pharmaceuticals USA Inc. (2023). Carbidopa tablet [package insert]. DailyMed.
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