Comtan contains the active ingredient entacapone, which is an inhibitor of catechol-O-methyltransferase and is available in 200 mg tablet form. It is designed to be used as an adjunct treatment in Parkinson's disease alongside levodopa and carbidopa therapy. The tablets include inactive ingredients such as corn starch, croscarmellose sodium, hypromellose, and iron oxides, among others.

How should I use this medication?

Take this medication by mouth with a glass of water at the same time you take your levodopa-carbidopa. Take it as directed on the prescription label. You can take it with or without food. If it upsets your stomach, take it with food. Keep taking it unless your care team tells you to stop.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store between 15 and 30 degrees C (59 and 86 degrees F). Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

• Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
• If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put in the trash, pour the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

What side effects may I notice from receiving this medication?

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
• Hallucinations
• Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
• Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision
• Muscle injury—unusual weakness or fatigue, muscle pain, dark yellow or brown urine, decrease in amount of urine
• New or worsening uncontrolled and repetitive movements of the face, mouth, or upper body
• Severe or prolonged diarrhea
• 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 yellow or brown urine
• Diarrhea
• Dry mouth
• Nausea
• Stomach pain
• Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

• Liver disease
• Mental health condition
• Narcolepsy
• Sleep apnea
• An unusual or allergic reaction to entacapone, other medications, foods, dyes, or preservatives
• Pregnant or trying to get pregnant
• Breast-feeding

What may interact with this medication?

Do not take this medication with any of the following:

• MAOIs, such as Marplan, Nardil, and Parnate

This medication may also interact with the following:

• Alcohol
• Ampicillin
• Apomorphine
• Bitolterol
• Certain medications for sleep or anxiety
• Chloramphenicol
• Dobutamine
• Dopamine
• Epinephrine
• Erythromycin
• Iron supplements
• Isoproterenol
• Linezolid
• Methyldopa
• Narcotic medications for pain
• Norepinephrine
• Probenecid
• Rifampin
• Warfarin

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse.

This medication may affect your coordination, reaction time, or judgment. Do not drive or operate machinery until you know how this medication affects you. Sit up or stand slowly to reduce the risk of dizzy or fainting spells. Drinking alcohol with this medication can increase the risk of these side effects.

When taking this medication, you may fall asleep without notice. You may be doing activities, such as driving a car, talking, or eating. You may not feel drowsy before it happens. Contact your care team right away if this happens to you.

There have been reports of increased sexual urges or other strong urges, such as gambling while taking this medication. If you experience any of these while taking this medication, you should report this to your care team as soon as possible.

This medication may cause urine to look dark yellow to orange or brown. This is normal and is not cause for concern.

You should check your skin often for changes to moles and new growths while taking this medication. Call your care team if you notice any of these changes.