tolcapone

tolcapone /tol·ca·pone/ (tōl´kah-pōn″) an antidyskinetic used as an adjunct to levodopa and carbidopa in the treatment of Parkinson's disease.

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tolcapone,

an antiparkinson agent.

indication It is used in the treatment of parkinsonism.

contraindication Known hypersensitivity to this drug prohibits its use.

adverse effects Life-threatening effects include hemolytic anemia, leukopenia, and agranulocytosis. Other adverse reactions include dystonia, dyskinesia, dreaming, psychosis, hallucinations, dizziness, chest pain, hypotension, cataract, eye inflammation, diarrhea, constipation, urinary tract infection, urine discoloration, uterine tumor, micturition disorder, sweating, and alopecia. Common side effects include fatigue, headache, confusion, orthostatic hypotension, nausea, vomiting, anorexia, and abdominal distress.

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tolcapone

Tasmar

Pharmacologic class: Catecholamine inhibitor

Therapeutic class: Antiparkinsonian

Pregnancy risk category C

FDA Boxed Warning

• Before prescribing or administering drug, make sure you're thoroughly familiar with prescribing information.
• Don't administer until prescriber has discussed risks with patient and patient has provided written acknowledgment that risks have been explained.
• Due to risk of hepatocellular injury (including potentially fatal, acute fulminant liver failure), drug ordinarily should be used in patients with Parkinson's disease who are receiving L-dopa/carbidopa, experiencing symptom fluctuations, and not responding satisfactorily to or not appropriate candidates for other adjunctive therapies. Withdraw therapy if patient doesn't show substantial benefit within 3 weeks of starting drug.
• Don't initiate therapy if patient has clinical evidence of hepatic disease. Don't restart therapy if patient developed hepatocellular injury while receiving drug and was withdrawn from therapy for any reason.
• Before and during therapy, obtain appropriate tests to exclude liver disease. Discontinue drug if alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels exceed two times the upper limit of normal or if clinical signs and symptoms suggest onset of hepatic dysfunction.

Action

Unknown. When given with levodopa-carbidopa, thought to reversibly inhibit catechol O-methyltranferase, leading to increased levodopa bioavailability and stimulation in brain.

Availability

Tablets: 100 mg, 200 mg

⊘Indications and dosages

➣ Adjunct to levodopa-carbidopa in idiopathic Parkinson's disease

Adults: Initially, 100 mg P.O. t.i.d. given with levodopa-carbidopa. If beneficial, may increase dosage to 200 mg P.O. t.i.d.; maximum dosage is 600 mg daily. If response inadequate after 3 weeks, stop therapy.

Contraindications

• Hypersensitivity to drug
• Nontraumatic rhabdomyolysis
• Drug-related hyperpyrexia or confusion
• Hepatic disease, alanine aminotransferase or aspartate aminotransferase elevation
• History of tolcapone-induced hepatocellular injury

Precautions

Use cautiously in:
• renal or cardiac disease, hypertension, asthma
• concurrent use of nonselective MAO inhibitor (such as phenelzine, tranylcypromine)
• pregnant or breastfeeding patients.

Administration

☞ Before giving first dose, obtain patient's written informed consent for drug therapy.
• Check liver function tests before starting drug.
☞ Don't stop drug abruptly, because this may cause a syndrome similar to neuroleptic malignant syndrome.
• Know that levodopa-carbidopa dosage may be decreased to minimize dyskinesia.

Route	Onset	Peak	Duration
P.O.	Unknown	2 hr	Unknown

Adverse reactions

CNS: dizziness, asthenia, headache, fatigue, hypokinesia, mental deficiency, agitation, tremor, hyperactivity, paresthesia, irritability, syncope, depression, speech disorder, confusion, sleep disorder, excessive dreaming, hallucinations, drowsiness, hypertonia, imbalance, falling, hyperkinesias, dystonia, dyskinesia

CV: hypotension, chest discomfort or pain, orthostatic hypotension, palpitations

EENT: tinnitus, sinus congestion, pharyngitis

GI: nausea, vomiting, diarrhea, constipation, dyspepsia, abdominal pain, flatulence, dry mouth, anorexia

GU: hematuria, urinary tract infection (UTI), urinary incontinence, urine discoloration, urinary disorder, erectile dysfunction

Hepatic: jaundice, severe hepatocellular injury (including fulminant hepatic failure, death)

Musculoskeletal: neck pain, arthritis, muscle cramps, stiffness, rhabdomyolysis

Respiratory: upper respiratory infection, dyspnea, bronchitis

Skin: rash, dermal bleeding, diaphoresis

Other: fever, influenza

Interactions

Drug-drug. Desipramine: increased risk of adverse tolcapone reactions

Nonselective MAO inhibitors (such as phenelzine, tranylcypromine): inhibition of principal pathways of tolcapone metabolism

Warfarin: increased warfarin blood level

Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase: increased levels

Patient monitoring

• Monitor parkinsonian symptoms during first 3 weeks of therapy. Report improvement (or lack thereof) to help determine if therapy should continue.
• Assess neurologic status closely.
☞ Monitor liver function tests. Watch closely for signs and symptoms of hepatic impairment.
• Closely monitor temperature. Stay alert for fever and other indications of infection (particularly upper respiratory infection, influenza, and UTI).

Patient teaching

• Tell patient to take drug with first levodopa-carbidopa dose of day.
☞ Advise patient to immediately report signs or symptoms of liver problems (persistent nausea, fatigue, appetite loss, dark urine, itching, tenderness on right side of abdomen, and yellowing of skin or eyes).
• Instruct patient to promptly report signs and symptoms of infection.
☞ Advise female patient to immediately report suspected pregnancy. Caution her not to breastfeed.
• Tell patient drug may cause involuntary movements, hallucinations, light-headedness, and other significant reactions. Urge him to use safety measures as needed.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Advise patient to move slowly when sitting up or standing, to avoid dizziness from sudden blood pressure decrease.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

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tolcapone

Tasmar^® Neurology A COMT inhibitor used with levodopa/carbidopa to treat Parkinson's disease Adverse effects Liver toxicity