Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of Entacapone with your doctor.

The following side effects have been reported by at least 1% of people taking Entacapone. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of Heart Attack (e.g., sudden chest pain or pain radiating to back, down arm, or jaw; sensation of fullness of the chest; nausea; vomiting; sweating; anxiety)
• signs of neuroleptic malignant syndrome (e.g., agitation; anxiety; confusion; fast, irregular, or pounding heartbeat; increased body temperature; muscle rigidity)
• signs of a severe skin reaction (i.e., blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)
• signs of a serious allergic reaction (i.e., abdominal cramps, difficulty breathing, rash, Hives, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Entacapone.

Each light brown, biconvex, ellipse-shaped, film-coated tablet, embossed "E200" on one side, plain on the other side contains entacapone 200 mg. Nonmedicinal ingredients: magnesium stearate, microcrystalline cellulose, povidone, and pregelatinized starch. Coating: iron oxide red, lecithin, polyethylene glycol, polyvinyl alcohol, talc, titanium dioxide, and yellow iron oxide.

Do not take entacapone if you:

• are allergic to entacapone or any ingredients of the medication
• are taking or have taken a non-selective monoamine oxidase inhibitor (MAOI) within the last 2 weeks (e.g., Moclobemide, Phenelzine, Tranylcypromine)
• have a previous history of neuroleptic malignant syndrome or rhabdomyolysis
• have liver impairment
• have pheochromocytoma (a tumour in the adrenal glands)
• have active heart, lung, kidney, blood, or hormonal disease
• have narrow-angle Glaucoma
• have or have had skin lesions that may be Melanoma
• have any condition where Epinephrine, norepinephrine, isoprenaline or dopamine should not be given

There may be an interaction between entacapone and any of the following:

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.

Behavioural and mood changes: Entacapone may cause mood and psychiatric changes, including hallucinations, hypersexuality, pathological gambling, and increased libido. Tell your doctor as soon as possible if you notice any unusual changes in your behaviour, have thoughts of harming yourself, or feel depressed.

If you have depression or a history of depression, discuss with your doctor how Entacapone may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Entacapone, and whether any special monitoring is needed. If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking Entacapone contact your doctor as soon as possible.

Diarrhea: Diarrhea is a common side effect of Entacapone. It may appear as early as the first week of starting treatment or many months after starting treatment. For some people, the diarrhea causes weight loss. If you notice any weight loss or have excessive diarrhea, contact your doctor.

Dizziness/reduced alertness: Entacapone may cause low blood pressure or dizziness and lightheadedness when rising from a lying or sitting position. People taking medications that can cause dizziness should rise slowly from sitting or lying down to reduce the possibility of severe dizziness or fainting. Do not drive, operate machinery, or perform other hazardous tasks until you have determined how Entacapone affects you.

Fructose intolerance: Entacapone contains fructose. If you have fructose intolerance, glucose-galactose malabsorption, or sucrase-isomaltase insufficiency, you should not take Entacapone. Talk to your doctor.

Heart disease: Entacapone may cause an increase in the risk of heart attack or heart disease. If you have a history of heart disease, discuss with your doctor how Entacapone may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Entacapone to build up in the body, causing side effects. Entacapone is not recommended for people with liver problems.

Melanoma: People with Parkinson's disease may be at increased risk of developing melanoma (a type of Skin Cancer). It is not known if this increased risk is due to Parkinson's disease or to the medications used to treat Parkinson's disease. Your doctor will monitor you for skin cancer while you are taking Entacapone. Talk to your doctor if you have any concerns.

Neuroleptic malignant syndrome (NMS): Entacapone may cause a potentially fatal reaction called neuroleptic malignant syndrome (NMS). If you develop symptoms of NMS, such as muscle stiffness, fever, confusion, sweating, or irregular heartbeat, stop taking Entacapone and seek immediate medical attention.

Prostate Cancer: A recent study has shown an increase in the number of cases of prostate cancer among men who have taken levodopa/carbidopa with or without entacapone for approximately 3 years. Although it is not clear whether this increased risk of prostate cancer is due to the medication or something else, it is important to have regular prostate examinations while taking medications for Parkinson's Disease.

Rhabdomyolysis (muscle breakdown): Occasionally, Entacapone may cause rapid breakdown of muscle tissue. If you notice signs of muscle weakness or pain, high body temperature, unexpected bruising, confusion, or difficulty passing urine, contact your doctor immediately.

Stopping Entacapone: Stopping Entacapone too quickly can cause potentially life-threatening side effects. Before stopping this medication, discuss the risks and benefits with your doctor. Do not stop taking Entacapone until you have spoken with your doctor first.

Sudden onset of sleep: There are reports of people who take this combination medication treatment (entacapone with levodopa - carbidopa) falling asleep without prior warning or drowsiness. If you have a sleep disorder, discuss this with your doctor. If you experience drowsiness while taking this medication, avoid driving or using machinery.

Pregnancy: Entacapone should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast feeding: It is not known if entacapone passes into breast milk. If you are a breast-feeding mother and are using Entacapone, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Entacapone have not been established for children less than 18 years of age.

Entacapone belongs to a group of medications called catechol-O-methyl transferase (COMT) inhibitors. It is used along with levodopa-carbidopa or levodopa-benserazide to treat Parkinson's Disease.

By inhibiting COMT enzymes that normally break down levodopa in the body, entacapone increases the amount of levodopa reaching the brain. This reduces the end-of-dose "wearing off" effect that some people taking levodopa may experience, thereby minimizing fluctuations in symptoms of Parkinson's disease. When taken on its own, entacapone has no effect on symptoms of Parkinson's disease.

Entacapone may be available under multiple brand names and/or in several different forms. Any specific brand name of Entacapone may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of Entacapone may not be used for all of the conditions discussed here.

Your doctor may have suggested Entacapone for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking Entacapone, speak to your doctor. Do not stop taking Entacapone without consulting your doctor.

Do not give Entacapone to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take Entacapone if their doctor has not prescribed it.