Formulary
Tolcapone: Indications, Dosing, Side Effects and Interactions
Tolcapone prevents the peripheral breakdown of levodopa, by inhibiting catechol- O -methyltransferase, allowing more levodopa to reach the brain.
MedNext Academy | 3 min read
Tolcapone: Indications, Dosing, Side Effects and Interactions
Tolcapone prevents the peripheral breakdown of levodopa, by inhibiting catechol- O -methyltransferase, allowing more levodopa to reach the brain.
Drug action
Tolcapone prevents the peripheral breakdown of levodopa, by inhibiting catechol- O -methyltransferase, allowing more levodopa to reach the brain.
Indications and dose
**Adjunct to co-beneldopa or co-careldopa in Parkinson's disease with 'end-of-dose' motor fluctuations if another inhibitor of peripheral catechol-O-methyltransferase inappropriate (under expert supervision)**
- **Adult** (By Mouth): 100 mg 3 times a day (max. per dose 200 mg 3 times a day) continuing beyond 3 weeks only if substantial improvement, leave 6 hours between each dose; first daily dose should be taken at the same time as levodopa with dopa-decarboxylase inhibitor, dose maximum only in exceptional circumstances.
Cautions
Most patients receiving more than 600 mg levodopa daily require reduction of levodopa dose by about 30% Cautions, further information Hepatotoxicity Potentially life-threatening hepatotoxicity including fulminant hepatitis reported rarely, usually in women and during the first 6 months, but late-onset liver injury also reported; discontinue if abnormal liver function tests or symptoms of liver disorder; do not re-introduce tolcapone once discontinued.
Contraindications
Phaeochromocytoma; previous history of hyperthermia; previous history of neuroleptic malignant syndrome; previous history of rhabdomyolysis; severe dyskinesia
Side effects
Common or very common Appetite decreased; chest pain; confusion; constipation; diarrhoea; dizziness; drowsiness; dry mouth; gastrointestinal discomfort; hallucination; headache; hyperhidrosis; influenza like illness; movement disorders; nausea; postural hypotension; sleep disorders; syncope; upper respiratory tract infection; urine discolouration; vomiting Uncommon Hepatocellular injury Rare or very rare Eating disorders; neuroleptic malignant syndrome (reported on dose reduction or withdrawal); pathological gambling; psychiatric disorders; sexual dysfunction
Interactions
**Other interactions (12):**
- Tasmar, as a COMT inhibitor, is known to increase the bioavailability of the co-administered levodopa.
- Levodopa has been associated with somnolence and episodes of sudden sleep onset.
- Patients must be informed of this and advised to exercise caution while driving or operating machines during treatment with levodopa.
- Furthermore a reduction of levodopa dose or termination of therapy may be considered.
- Catechols and other drugs metabolised by catechol- O -methyltransferase (COMT) Tolcapone may influence the pharmacokinetics of drugs metabolised by COMT.
- The plasma concentrations of benserazide observed after co-administration of tolcapone and benserazide-25 mg/levodopa were still within the range of values observed with levodopa/benserazide alone.
Pregnancy
Toxicity in animal studies-use only if potential benefit outweighs risk.
Breast feeding
Avoid-present in milk in animal studies.
Hepatic impairment
Manufacturer advises avoid.
Renal impairment
Caution if creatinine clearance less than 30 mL/minute. M See Prescribing in renal impairment .
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
FormularyBrowse all drugs
Search 1,850+ drug profiles.
Study Tolcapone in the MedNext app
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary

