This combination medication is used to treat symptoms of Parkinson's disease or Parkinson-like symptoms (such as shakiness, stiffness, difficulty moving). Parkinson's disease is thought to be caused by too little of a naturally occurring substance (dopamine) in the brain. Levodopa changes into dopamine in the brain, helping to control movement. Carbidopa prevents the breakdown of levodopa in the bloodstream so more levodopa can enter the brain. Carbidopa can also reduce some of levodopa's side effects such as nausea and vomiting.

Take this medication by mouth with or without food as directed by your doctor, usually 2 to 3 times a day. Doses are usually taken 4 to 8 hours apart while awake.

Do not crush or chew this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split the tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing.

Taking this medication with food may help to decrease nausea. It is best to avoid a high-protein diet (it decreases the amount of levodopa that your body takes in) during treatment, unless directed otherwise by your doctor. Separate your dose of this medication by as many hours as possible from any iron supplements or products containing iron (such as multivitamins with minerals) you may take. Iron can reduce the amount of this medication absorbed by the body. Consult your doctor or pharmacist for more details.

The dosage is based on your medical condition and response to treatment. If you are switching from immediate-release levodopa/carbidopa to this product, your doctor may slightly increase your dose of this medication to get the same response. This medication may take a little longer to work in the morning than the immediate-release medication because it is absorbed more slowly. Let your doctor know if this becomes a problem.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Your doctor may also prescribe immediate-release carbidopa/levodopa or carbidopa alone to be taken with this medication. Make sure you understand your dosing schedule and follow it closely.

Some patients may experience a "wearing-off" (worsening of symptoms) before the next dose is due. An "on-off" effect might also occur, in which sudden short periods of stiffness occur. If these effects occur, contact your doctor for possible dose adjustments that may help to lessen this effect.

Do not stop taking this medication without consulting your doctor. Some conditions may become worse when this medication is suddenly stopped. Also, if you suddenly stop using this medication, you may have withdrawal symptoms (such as anxiety, depression, confusion, fever, muscle stiffness). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used this medication for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal.

Tell your doctor if your condition does not get better or if it gets worse.

Dizziness, lightheadedness, nausea, vomiting, loss of appetite, trouble sleeping, unusual dreams, or headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

This medication may cause saliva, urine, or sweat to turn a dark color. This effect is harmless, but your clothes may be stained.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Some people taking this medication have fallen asleep suddenly during their usual daily activities (such as talking on the phone, driving). In some cases, sleep occurred without any feelings of drowsiness beforehand. This sleep effect may occur anytime during treatment with this medication even if you have used this medication for a long time. If you experience increased sleepiness or fall asleep during the day, do not drive or do other possibly dangerous activities until you have discussed this effect with your doctor. Your risk of this sleep effect is increased by using alcohol or other medications that can make you drowsy. See also Precautions section.

Tell your doctor right away if you have any serious side effects, including:

• new/worsening movements you can't control/spasms
• greatly increased eye blinking/twitching
• vision changes (such as blurred vision, double vision)
• eye pain
• severe stomach/abdominal pain
• black/tarry stools
• vomit that looks like coffee grounds
• mental/mood changes (such as confusion, agitation, hallucinations)
• signs of infection (such as sore throat that doesn't go away)
• easy bleeding/bruising
• unusual tiredness
• tingling of the hands/feet
• unusual strong urges (such as increased gambling, increased sexual urges)

Get medical help right away if you have any very serious side effects, including:

• chest pain
• fainting

Abruptly stopping or reducing the dose of this medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms:

• fever
• unusual muscle stiffness
• severe confusion
• sweating
• fast/irregular heartbeat

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking this medication, tell your doctor or pharmacist if you are allergic to carbidopa or levodopa; or to foscarbidopa or foslevodopa; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver disease
• glaucoma
• breathing problems (such as asthma)
• heart disease (such as heart attack, irregular heartbeat)
• kidney disease
• stomach/intestinal ulcer
• mental/mood disorders (such as depression, schizophrenia)
• blood disorders
• seizures
• sleep disorders

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). See also Side Effects section.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

Levodopa passes into breast milk. It is unknown if carbidopa passes into breast milk. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. However, certain MAO inhibitors (rasagiline, safinamide, selegiline) may be used with careful monitoring by your doctor. Ask your doctor when to start or stop taking this medication.

This medication may interfere with certain lab tests (such as urine catecholamine/glucose/ketone tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: severe dizziness, irregular heartbeat, mental/mood changes (such as agitation).

Do not share this medication with others.

Lab and/or medical tests (such as complete blood count, heart/kidney/liver function, blood pressure) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.