tolcapone

Acts as a selective and reversible inhibitor of the enzyme catechol-O-methyltransferase.
Inhibition of this enzyme prevents the breakdown of levodopa, greatly increasing its availability to the CNS.

Therapeutic effects:

Prolongs duration of response to levodopa without end-of-dose motor fluctuations.
Decreased signs and symptoms of Parkinson’s disease.

Pharmacokinetics ⬆ ⬇

Absorption: Rapidly absorbed following oral administration with 65% bioavailability.

Distribution: Unknown.

Protein Binding: >99% bound to plasma proteins.

Metabolism/Excretion: Mostly metabolized by the liver; <0.5% excreted unchanged in urine.

Half-Life: 2–3 hr.

Time/Action Profile ⬆ ⬇

(blood levels)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	1.7 hr	8 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Concurrent MAO inhibitor therapy;
Clinical evidence of liver disease.

Use Cautiously in:

Severe renal impairment (safety not established if CCr <25 mL/min);
OB: Lactation: Safety not established.

Adv. Reactions/Side Effects ⬆ ⬇

CV: orthostatic hypotension

Derm: ↑sweating, melanoma

GI: constipation, diarrhea, ↑liver enzymes, anorexia, HEPATOTOXICITY, nausea, vomiting

GU: hematuria, yellow discoloration of urine

Neuro: dyskinesia, dystonia, headache, sleep disorder, hallucinations, syncope, urges (gambling, sexual)

Interactions ⬆ ⬇

Drug-drug:

Concurrent use with MAO inhibitors is not recommended; both agents inhibit the metabolic pathways of catecholamines.
May ↑ the effects of apomorphine, dobutamine, or isoproterenol; dose reduction may be necessary.
↑the bioavailability of levodopa by two-fold; this is a desired effect.

Route/Dosage ⬆ ⬇

PO (Adults ): 100 mg 3 times daily; may cautiously ↑ to 200 mg 3 times daily if benefit is justified.

Availability ⬆ ⬇

(Generic available)

Tablets: 100 mg

Assessment ⬆ ⬇

Assess patient for signs and symptoms of Parkinson’s disease (tremor, muscle weakness and rigidity, ataxic gait) prior to and throughout therapy.
Assess BP periodically during therapy.
Monitor for signs and symptoms of liver dysfunction (persistent nausea, fatigue, lethargy, anorexia, jaundice, dark urine, pruritus, right upper quadrant tenderness) periodically during therapy.

Lab Test Considerations:

Monitor liver function tests before every 2–4 wk for the first 6 mo following initiation or dose increase and periodically thereafter. Discontinue tolcapone if liver function tests reach two times the upper limit of normal or if jaundice occurs; do not reinstate.

Implementation ⬆ ⬇

PO: Administer 1st dose of the day of tolcapone together with carbidopa/levodopa. Administer subsequent doses 6 and 12 hr later.
- May be administered without regard to food.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed. Caution patient not to discontinue tolcapone without consulting health care professional. Abrupt discontinuation or rapid dose reduction may result in neuroleptic malignant syndrome (↑ temperature, muscular rigidity, altered consciousness).
Caution patient to make position changes slowly to minimize orthostatic hypotension, especially at the beginning of therapy.
May affect mental and/or motor performance. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Advise patient to avoid taking alcohol or other CNS depressants concurrently with tolcapone.
Inform patient and caregiver that hallucinations, nausea, dyskinesia, or dystonia may occur during tolcapone therapy.
Instruct patient to notify health care professional if persistent diarrhea occurs.
Advise patient to notify health care professional if symptoms of liver failure (clay-colored stools, jaundice, fatigue, loss of appetite, lethargy), suspicious or unusual skin changes, hallucinations, or new or increased gambling, sexual, or other intense urges occur.
Advise patient to notify health care professional if pregnancy is planned or suspected.
Emphasize the importance of routine follow-up exams.

Evaluation/Desired Outcomes ⬆ ⬇

Decrease in signs and symptoms of Parkinson’s disease.

US Brand Names ⬆ ⬇

Code ⬆

NDC Code

0187- Bausch Health US LLC
- 0187-0938- Tasmar
  - 0187-0938-01- 90 TABLET, FILM COATED in 1 BOTTLE (0187-0938-01)

17511- COHANCE LIFESCIENCES LIMITED
- 17511-119-
  - 17511-119-06- 1 kg in 1 DRUM (17511-119-06)

50742- Ingenus Pharmaceuticals, LLC
- 50742-193- TOLCAPONE
  - 50742-193-90- 90 TABLET in 1 BOTTLE (50742-193-90)

65085- Piramal Pharma Limited
- 65085-0032-
  - 65085-0032-1- 25 kg in 1 DRUM (65085-0032-1)

65085- Piramal Pharma Limited
- 65085-0032-
  - 65085-0032-2- 10 kg in 1 DRUM (65085-0032-2)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-3- 15 kg in 1 DRUM (65085-0032-3)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-4- 20 kg in 1 DRUM (65085-0032-4)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-5- 5 kg in 1 DRUM (65085-0032-5)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-6- 5 kg in 1 DRUM (65085-0032-6)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-7- 10 kg in 1 DRUM (65085-0032-7)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-8- 10 kg in 1 DRUM (65085-0032-8)

65085- Piramal Pharma Limited
- 65085-0032-
  65085-0032-9- 20 kg in 1 DRUM (65085-0032-9)

68682- Oceanside Pharmaceuticals
- 68682-938- Tolcapone
  68682-938-90- 90 TABLET, FILM COATED in 1 BOTTLE (68682-938-90)

76438- Anthem Biosciences Limited
- 76438-001-
  - 76438-001-01- 25000 g in 1 DRUM (76438-001-01)

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇