SIDE EFFECTS: See also Warning section. Nausea/vomiting, unwanted/uncontrolled movements, diarrhea, headache, drowsiness, trouble sleeping, increased number of dreams, increased sweating, dry mouth, gas, and abdominal pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. To avoid 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 tolcapone 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 tolcapone 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 change color (such as increased yellow color). This effect is harmless. Tell your doctor right away if you have any serious side effects, including: easy bleeding/bruising, chest pain, fast/irregular heartbeat, fever, mental/mood changes (such as agitation, confusion, hallucinations), unusual strong urges (such as increased gambling, increased sexual urges), muscle pain/soreness/stiffness/weakness, pain/trouble with breathing. A very serious allergic reaction to this drug is rare. However, seek immediate medical attention 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: See also Warning section. Before taking tolcapone, 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, low blood pressure, Parkinson's with severe movement problems, liver problems, mental/mood disorders (such as psychosis, schizophrenia), history of a certain muscle problem (rhabdomyolysis), fever and confusion caused by any drug. 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, confusion, and hallucinations. During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. It is not known if this medication passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: The effects of some drugs can change if you take other drugs or herbal products at the same time. This can increase your risk for serious side effects or may cause your medications not to work correctly. These drug interactions are possible, but do not always occur. Your doctor or pharmacist can often prevent or manage interactions by changing how you use your medications or by close monitoring. To help your doctor or pharmacist give you the best care, be sure to tell your doctor or pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products) before starting treatment with this product. While using this product, do not start, stop, or change the dosage of any other medicines you are using 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. Tolcapone 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. This document does not contain all possible interactions. Keep a list of all the products you use. Share this list with your doctor and pharmacist to lessen your risk for serious medication problems.

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.