Note: This document contains side effect information about entacapone. Some dosage forms listed on this page may not apply to the brand name Comtan.
Summary
Common side effects of Comtan include: urine discoloration. Continue reading for a comprehensive list of adverse effects.
Applies to entacapone: oral tablets.
Side effects include:
Dyskinesia, nausea, hyperkinesia, diarrhea, urine discoloration, hypokinesia, dizziness, abdominal pain, constipation, fatigue.
For Healthcare Professionals
Applies to entacapone: oral tablet.
Nervous system
There were no cases of neuroleptic malignant syndrome during clinical trials. Since market introduction, there have been isolated cases, especially following abrupt reduction or discontinuation of this drug and other concomitant dopaminergic drugs.[Ref]
Very common (10% or more): Dyskinesia (up to 27%), hyperkinesia (10%)
Common (1% to 10%): Hypokinesia, dizziness, somnolence, taste perversion, aggravated parkinsonism, dystonia, headache, tremor
Frequency not reported: Falling asleep during activities of daily living
Postmarketing reports: Neuroleptic malignant syndrome[Ref]
Gastrointestinal
Very common (10% or more): Nausea (up to 14%), diarrhea (up to 11%)
Common (1% to 10%): Abdominal pain, constipation, vomiting, dry mouth, dyspepsia, flatulence, gastritis, gastrointestinal disorders
Very rare (less than 0.01%): Anorexia
Postmarketing reports: Colitis[Ref]
In clinical trials, diarrhea occurred in approximately 10% of patients. It was generally mild to moderate, but in 1.3% of people it was severe. Upon discontinuation, diarrhea generally resolved. There have been postmarketing reports of drug-induced microscopic colitis, primarily lymphocytic colitis.[Ref]
Genitourinary
Very common (10% or more): Urine discoloration (10%)[Ref]
General
The most commonly reported adverse reactions included dyskinesia, urine discoloration, diarrhea, nausea, hyperkinesia, abdominal pain, vomiting, and dry mouth.[Ref]
Respiratory
Common (1% to 10%): Dyspnea
Frequency not reported: Pulmonary fibrosis[Ref]
Dermatologic
Common (1% to 10%): Increased sweating
Rare (less than 0.1%): Erythematous, maculopapular rash
Very rare (less than 0.01%): Urticaria
Frequency not reported: Skin hair, beard, and nail discolorations[Ref]
Musculoskeletal
Isolated cases of rhabdomyolysis have occurred in patients treated with this drug. The complicated nature of these cases makes it difficult to determine the role this drug may have had. Rhabdomyolysis has been reported secondary to severe dyskinesias or neuroleptic malignant syndrome (NMS) in patients with Parkinson's disease.[Ref]
Common (1% to 10%): Back pain, falls, leg cramps
Postmarketing reports: Rhabdomyolysis[Ref]
Psychiatric
Common (1% to 10%): Anxiety, insomnia, hallucinations, confusion, paranoia
Uncommon (0.1% to 1%): Agitation
Frequency not reported: Impulse control disorders including pathological gambling, increased libido, hypersexuality, compulsive spending or buying, binge eating and compulsive eating[Ref]
Hematologic
Common (1% to 10%): Purpura, decreased hemoglobin[Ref]
A clinically significant decrease in hemoglobin has been observed in 1.8% of patients. The underlying mechanism may involve decreased absorption of iron from the gastrointestinal tract.[Ref]
Other
Common (1% to 10%): Fatigue, asthenia, pain, vertigo[Ref]
Cardiovascular
The incidence of myocardial infarction and other ischemic heart disease events was 0.43% and 1.54%, respectively, in an analysis of 13 double-blind studies involving 2082 patients.[Ref]
Common (1% to 10%): Ischemic heart disease events other than myocardial infarction (e.g., angina pectoris, postural hypotension
Uncommon (0.1% to 1%): Myocardial infarction[Ref]
Hepatic
Rare (less than 0.1%): Abnormal liver function tests
Postmarketing reports: Hepatitis with mainly cholestatic features[Ref]