126.96.36.199 Catechol-O-methyltransferase inhibitors (COMT inhibitors)
- Note the difference in dosage instructions between COMT inhibitors. Entacapone is taken at the same time as levodopa medication. Opicapone is taken once a day at bedtime, at least 1 hour before or after levodopa medication.
- 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.