Classifications: catecholamine o-methyltransferase (comt) inhibitor; antiparkinson agent; Therapeutic: antiparkinson agent
Pregnancy Category: C
200 mg tablets
Selective inhibitor of catecholamine O-methyltransferase (COMT). COMT is responsible for metabolizing levodopa to an intermediate
compound 3-O-methyldopa, a chemical which interferes with the availability of levodopa to the brain. Therefore, it increases
availability of levodopa in CNS.
Taken with levodopa, it decreases the formation of 3-O-methyldopa, thus increasing the duration of the motor response of the
brain to levodopa in Parkinson's disease. Effectiveness is indicated by diminished Parkinson's manifestations.
Adjunct to levodopa/carbidopa to treat Parkinson's disease.
Hypersensitivity to entacapone; concurrent MAO inhibitors; children; pregnancy (category D).
Hepatic impairment; biliary obstruction; concomitant administration with CNS depressants; drugs metabolized by COMT (e.g.,
isoproterenol, epinephrine, etc.); history of hypotension or syncope; lactation.
Route & Dosage
Adult: PO 200 mg administered with each dose of levodopa/carbidopa up to 8 times/d
- Give simultaneously with each levodopa/carbidopa dose.
- Must be tapered if discontinued. Never discontinue abruptly.
- Do not administer to patients receiving nonselective MAO inhibitors.
- Store at 15°30° C (59°86° F).
Adverse Effects (≥1%)Body as a Whole:
Back pain, fatigue
, asthenia. CNS: Dyskinesia, hyperkinesia,
hypokinesia, dizziness, anxiety, somnolence, agitation. GI:
Taste perversion, nausea, diarrhea,
abdominal pain, constipation
, vomiting, dry mouth, dyspepsia, flatulence, gastritis
. Respiratory: Dyspnea
Increased sweating. Other: Urine discoloration,
Extreme caution must be used if administered with a nonselective maoi
; bitolterol, dobutamine, dopamine, epinephrine, isoetharine, isoproterenol, methyldopa, norepinephrine
may increase heart rates, possibly cause arrhythmias, excessive changes in BP.
Rapidly absorbed, 35% bioavailable. Peak:
1 h. Distribution:
Highly protein bound. Metabolism:
Extensively metabolized in plasma
Primarily in feces. Half-Life:
2.4 h (terminal).
Assessment & Drug Effects
- Monitor carefully for hyperpyrexia, confusion, or emergence of Parkinson's S&S during drug withdrawal.
- Monitor for orthostatic hypotension & worsening of dyskinesia or hyperkinesia.
- Lab tests: Hgb and serum ferritin levels with prolonged therapy.
Patient & Family Education
- Take with levodopa/carbidopa; not effective alone.
- Do not discontinue abruptly; gradually reduce dosage.
- Exercise caution when rising from a sitting or lying position because faintness/dizziness can occur.
- Exercise caution with hazardous activities until reaction to the drug is known.
- Harmless brownish-orange discoloration of urine is possible.
- Report unusual adverse effects (e.g., hallucinations/unexplained diarrhea).