Home Formulary 4.0 Central Nervous System 4.9 Drugs used in parkinsonism and related disorders 4.9.1 Dopaminergic drugs used in parkinsonism 4.9.1.4 Dopamine enzyme inhibitors / catechol-O-methyltransferase inhibitors (COMT inhibitors)

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4.9.1.4 Dopamine enzyme inhibitors / catechol-O-methyltransferase inhibitors (COMT inhibitors)

ChoiceDrugDosage
1st choiceEntacapone tablets 200mgDose:
See BNF - seek specialist advice
2nd choiceTolcapone 100mg tabletsDose:
See BNF and Shared Care Guideline- seek specialist advice

Prescribing Notes

  • A triple combination preparation of levodopa, carbidopa and entacapone may be suitable for patients requiring entacapone who are having problems with concordance. Prescribe by brand – Sastravi® and Stanek®  are currently the ‘branded generic’ combination preparations with the lowest acquisition cost.
  • Due to the risk of hepatotoxicity, tolcapone should be prescribed under specialist supervision only, when other COMT inhibitors combined with co-beneldopa or co-careldopa are ineffective or not tolerated. LFT monitoring is required (see shared care guideline).
  • The levodopa dose may need to be adjusted when a COMT inhibitor is initiated.
  • Tolcapone should only be continued beyond three weeks if there is substantial improvement in symptom control.