Doxepin and Fentanyl: interaction and safety
This source-based reference is not a personal treatment recommendation. The relevance and management of an interaction depend on the exact products, route, dose and clinical situation.
Interaction mechanism
Additive central nervous system depression with the 3 mg/6 mg doxepin insomnia formulation.
Clinical significance and safety
This doxepin record covers the 3 mg/6 mg insomnia tablet, a sedating sleep medicine. With fentanyl, CNS-depressant effects can add. Opioid prescribing information warns that concomitant sedative-hypnotics can increase profound sedation and respiratory depression, including potentially fatal outcomes; the low-dose doxepin label also warns about additive CNS depression. This is not an absolute contraindication or an assertion that harm is inevitable. Any overlap needs an individual prescriber-directed plan; do not change either treatment independently. Very slow breathing, inability to wake or collapse requires emergency help. Antidepressant-dose doxepin assumptions are not being applied to this low-dose formulation.
Using this information
This is a source-based reference record, not a recommendation to combine, stop or change medicines. A missing interaction record does not establish safe use. A qualified healthcare professional should consider the exact products, doses, other medicines and individual health circumstances.