PDF 54kAre there any drug interactions to consider?
Usual care should be taken with the use of any other drugs known to depress the CNS.
Ritonavir has been shown to reduce the clearance of IV fentanyl by two thirds and so may, if used with transdermal fentanyl, result in an increase in fentanyl plasma concentrations which could increase or prolong both therapeutic and adverse effects and may cause serious respiratory depression.
Prescribing information and a summary of product characteristics PDF 54k
The concomitant use of ritonavir and transdermal fentanyl is not recommended, unless the patient is closely monitored and any such use should be carried out under the guidance of a Specialist Palliative Care team.
