carbidopa / levodopa
Sinemet (carbidopa / levodopa) is a combination medication made up of carbidopa and levodopa. It's one of the first-choice options for Parkinson's disease (PD) to relieve symptoms, such as shakiness and slowed movement. The medication comes in many forms and strengths, but it must be taken multiple times per day in order to relieve your PD symptoms.
What is Sinemet (carbidopa / levodopa)?
What is Sinemet (carbidopa / levodopa) used for?
Parkinson's disease (PD)
Parkinsonism (conditions that cause people to have signs and symptoms of PD, including slowness, stiffness, shakiness, and imbalance)
How Sinemet (carbidopa / levodopa) works
Sinemet (carbidopa / levodopa) is a combination of two medications: carbidopa and levodopa. By working together, these medications help relieve symptoms of Parkinson's disease (PD), which occur due to low dopamine levels in the brain.
Levodopa is a dopamine replacement. Levodopa travels into your brain, where it's converted into dopamine. It helps relieve PD symptoms by restoring dopamine in your brain.
Carbidopa is a dopa decarboxylase inhibitor. Dopa decarboxylase is a protein in your body that breaks down levodopa before it can travel into your brain. By blocking this protein, carbidopa prevents levodopa from breaking down. This raises the level of levodopa in your body and allows more levodopa to travel into your brain to be converted into dopamine. Levodopa and dopamine can then reach and remain at higher levels in your brain, which enhances levodopa's ability to relieve PD symptoms.
Drug Facts
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What are the side effects of Sinemet (carbidopa / levodopa)?
Other Side Effects
- Hallucinations
- Confusion
- Headache
- Dizziness
- Depression
- Unusual dreams
- Vomiting
- Common cold
- Shortness of breath
- Urinary tract infection (UTI)
- Dark-colored saliva, sweat, or urine
Serious Side Effects
- Neuroleptic malignant syndrome (NMS): very high fevers, confusion, 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
- Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
- Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision
- 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
- Stomach bleeding—bloody or black, tar-like stools, vomiting blood or brown material that looks like coffee grounds
- 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
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
- Dark red or black saliva, sweat, or urine
- Dizziness
- Drowsiness
- Headache
- Nausea
Pros and cons of Sinemet (carbidopa / levodopa)
Pros
First-choice option for treating PD symptoms
Available in many forms: immediate-release tablets, extended-release tablets, and orally disintegrating tablets
Available in multiple strengths, so your provider can prescribe a higher dose if needed
Available in a lower-cost generic form
Cons
Usually needs to be taken multiple times per day to control PD symptoms
Can make you very sleepy and cause you to fall asleep suddenly
Can darken the color of your saliva, sweat, and urine
Might not work as well if your PD symptoms worsen
Pharmacist tips for Sinemet (carbidopa / levodopa)
If you were previously taking levodopa, stop taking levodopa at least 12 hours before you start taking the combination medication to lower your risk of side effects. For example, you can take your last dose of levodopa before bedtime and start taking Sinemet (carbidopa / levodopa) in the morning.
You might start to notice an improvement in your PD symptoms in about 30 minutes after a dose. But it might take several months before you feel the maximum benefit of Sinemet (carbidopa / levodopa). Keep in mind that your healthcare team might need to make changes to your dose to help you find one that works best.
Sinemet (carbidopa / levodopa) 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.
You can take Sinemet (carbidopa / levodopa) with food to lower the risk of stomach upset. Avoid taking the medication with food that's high in protein, such as meat, milk, cheese, or nuts. They can affect how fast and how much medication is absorbed by your body, which can affect how well the medication works.
You might have more difficulty controlling your body's movements (dyskinesia) after starting Sinemet (carbidopa / levodopa). This side effect is more common for people who've been taking this medication for a while (years). If this becomes bothersome, let your provider know, so they can prescribe a lower dose of medication.
If you're taking the orally disintegrating tablets, don't remove the tablets from the bottle until it's time for your dose. Carefully remove the tablet from the bottle with dry hands, and place it on your tongue. The tablets will dissolve on your tongue, so you don’t need to take it with water.
Iron and medications, vitamins, and supplements containing iron can interfere with Sinemet (carbidopa / levodopa) and affect how much of the medication is absorbed into your body. Avoid taking Sinemet (carbidopa / levodopa) at the same time as iron, and spread them out as far as you possibly can.
Frequently asked questions about Sinemet (carbidopa / levodopa)
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What are the risks and warnings for Sinemet (carbidopa / levodopa)?
Sinemet (carbidopa / levodopa) 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
Sinemet (carbidopa / levodopa), 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. Also avoid taking medications that make you sleepy while taking Sinemet (carbidopa / levodopa), since this can make you feel even sleepier. Let your provider know if you feel very sleepy during the daytime or if you fall asleep during activities where you need to concentrate.
High fevers and confusion
Although rare, stopping Sinemet (carbidopa / levodopa) or lowering your dose can cause side effects similar to those of neuroleptic malignant syndrome (NMS). This is a life-threatening condition that's caused by certain mental health medications. It can cause very high fevers, confusion, irregular pulse, sweating, muscle stiffness, and changes in blood pressure. NMS is treatable if it's recognized early. Don't stop taking Sinemet (carbidopa / levodopa) or lower your dose without talking to your provider, so they can instruct you on how to stop the medication safely.
Hallucinations and changes in behavior and thoughts
Risk factors: History of certain mental health conditions
Sinemet (carbidopa / levodopa) and medications that raise your dopamine levels can cause hallucinations and changes in behavior and thinking, such as paranoia, delusions, confusion, aggressive behavior, uneasiness, trouble sleeping, lots of dreaming, and less awareness of your surroundings. Generally, these symptoms can occur shortly after you start taking these medications and they might go away once you stop taking this medication or if your dose is lowered. Because of this risk, you shouldn't take Sinemet (carbidopa / levodopa) if you have certain mental health conditions. Certain mental health medications, such as haloperidol (Haldol) or perphenazine, can worsen your Parkinson's disease and might affect how well Sinemet (carbidopa / levodopa) works.
Difficulty controlling impulsive behavior
Sinemet (carbidopa / levodopa) and other Parkinson's disease medications can cause changes in people's behavior, including strong sexual or gambling urges, urges to spend a lot 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 Sinemet (carbidopa / levodopa), so your provider might ask you if you've recently had these behaviors at your next visit.
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. Tell your healthcare provider if you notice any of these changes on your skin. Your provider might recommend occasional skin examinations.
Sinemet (carbidopa / levodopa) dosage forms
Typical dosing for Sinemet (carbidopa / levodopa)
Sinemet (carbidopa / levodopa) comes in three different forms: immediate-release tablets, extended-release tablets, and orally disintegrating tablets. The dose will depend on how you respond to the medication. Your healthcare provider will slowly raise your dose until your symptoms of PD are relieved.
Immediate-release tablets and orally disintegrating tablets: The typical starting dose is 25 mg/100 mg (carbidopa/levodopa) by mouth 3 times per day.
Extended-release (ER) tablets: The typical starting dose is 50 mg/200 mg (carbidopa/levodopa) by mouth 2 times per day at least 6 hours apart.
How much does Sinemet (carbidopa / levodopa) cost?
Sinemet (carbidopa / levodopa) contraindications
Take mental health medications called nonselective monoamine oxidase inhibitors (MAOIs)
Narrow-angle glaucoma
What are alternatives to 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)
Parkinson's disease (PD)
Parkinsonism (conditions that cause people to have symptoms of PD, including tremors, slowness, and stiffness)
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