Entacapone

INTRODUCTION

Indications

With levodopa/carbidopa to treat idiopathic Parkinson's disease when signs and symptoms of end-of-dose “wearing-off” (so-called fluctuating patients) occur.

Action

Acts as a selective and reversible inhibitor of the enzyme catechol-O-methyltransferase (COMT). Inhibition of this enzyme prevents the breakdown of levodopa, increasing availability to the CNS. Therapeutic Effects: Prolongs duration of response to levodopa with end-of-dose motor fluctuations. Decreased signs and symptoms of Parkinson's disease.

Adverse Reactions/Side Effects

CNS: NEUROLEPTIC MALIGNANT SYNDROME, dizziness, hallucinations, syncope. Resp: pulmonary infiltrates, pleural effusion, pleural thickening. CV: hypotension. GI: abdominal pain, diarrhea, nausea (during initiation), retroperitoneal fibrosis. GU: brownish orange discoloration of urine. MS: RHABDOMYOLYSIS. Neuro: dyskinesia.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for signs of neuroleptic malignant syndrome, including hyperthermia, diaphoresis, generalized muscle rigidity, hallucinations, altered mental status, tachycardia, changes in blood pressure (BP), and incontinence. Symptoms typically occur within 4–14 days after initiation of drug therapy, but can occur at any time during drug use. Report these signs to the physician immediately.

• Assess any muscle pain, tenderness, or weakness, especially if accompanied by fever, malaise, and dark-colored urine. Advise patient that these symptoms may represent drug-induced myopathy, and that myopathy can progress to severe muscle damage (rhabdomyolysis). Report any unexplained musculoskeletal symptoms to the physician immediately.

• Assess gait and motor function to help determine antiparkinson effects, especially when starting drug therapy or during dosing changes or addition of other antiparkinson drugs. Motor function should be assessed at different times of the day, such as when drugs are reaching peak therapeutic levels (i.e., 30–60 min after oral dose), as well as when drug effects are minimal (just before the next dose).

• Document increased side effects such as involuntary movements (dyskinesias) or fluctuations in response (on-off phenomenon, end-of-dose akinesia). Notify physician because increased side effects might require dose adjustment or a change in medication regimen.

• Assess BP periodically and compare to normal values (See Appendix F). Report low BP (hypotension), especially if patient experiences increased dizziness, fainting, or other symptoms.

• Monitor respiratory function at rest and during exercise. Notify physician if patient experiences signs of pulmonary infiltrates or pleural effusion, including cough, shortness of breath, chest pain, or labored breathing.

• Assess dizziness and syncope that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Implement therapeutic exercises (coordination exercises, gait training, cardiovascular conditioning) to complement the effects of drug therapy and help achieve optimal function.

• Guard against falls and trauma (hip fractures, head injury, and ...