Fentanyl
Subsys is a brand-name sublingual fentanyl spray used to manage breakthrough cancer pain in opioid-tolerant patients already receiving around-the-clock pain medication. This rapid-acting formulation delivers fentanyl through the oral mucosa for quick pain relief.
Subsys is a fast-acting fentanyl spray for breakthrough cancer pain in patients already on chronic opioid therapy.
Key facts at a glance
- RxNorm
- 1237051
- Generic
- Subsys
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Management of breakthrough cancer pain in opioid-tolerant adult patients who are already receiving, and are tolerant to, around-the-clock opioid therapy for underlying cancer pain.
Subsys delivers fentanyl, a potent synthetic opioid agonist, through sublingual absorption. As an opioid receptor agonist, it binds to mu-opioid receptors in the brain and nervous system to reduce pain perception.
This medication carries a black box warning for addiction, abuse, misuse, and potentially fatal respiratory depression. It is contraindicated in opioid non-tolerant patients. Subsys is a Schedule II controlled substance and must be prescribed and dispensed according to REMS requirements. Only for patients with breakthrough cancer pain; not for headaches, dental pain, or post-operative pain.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 9, 2026. · Read our editorial policy