SIDE EFFECTS: Nausea, vomiting, diarrhea, unwanted/uncontrolled movements, increased sweating, drowsiness, tiredness, dry mouth, gas, and abdominal pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Lightheadedness or dizziness upon standing may also occur, especially during the first few weeks of treatment. To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication may develop serious side effects, but with frequent visits to your doctor, this risk can be minimized. Some people taking entacapone 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 entacapone 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 take part in 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. Your urine may turn brownish-orange. This effect is harmless. Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as confusion, hallucinations), unusual strong urges (such as increased gambling, increased sexual urges), fever, muscle stiffness, persistent diarrhea, easy bleeding/bruising, sore/painful muscles, muscle weakness, trouble breathing, pain with breathing. 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.

PRECAUTIONS: Before taking entacapone, tell your doctor or pharmacist if you are allergic to it; 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: alcoholism, liver problems, low blood pressure, mental/mood disorders (such as depression, schizophrenia), sleep disorders. This drug may make you dizzy or drowsy. Alcohol or marijuana 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. 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). Older adults may be more sensitive to the side effects of this drug, especially drowsiness and confusion. During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: 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. Some of the products that may interact with this drug include: certain MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, tranylcypromine). Other MAO inhibitors (safinamide, selegiline, rasagiline) may be used cautiously with close monitoring by your doctor. If you are taking rasagiline or selegiline for Parkinson's disease, ask your doctor if you should continue taking it. Entacapone can slow down the removal of other drugs from your body, thereby affecting how they work. These affected drugs include apomorphine, dobutamine, and methyldopa. This is not a complete list. Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

OVERDOSE: 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 their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include severe drowsiness, coma, confusion, agitation.