About fentanyl
Opioid analgesic
Used for
- Severe pain when other pain relief is inadequate
- Pain relief during surgery and anesthesia
Usual adult dose
Dose is individualized by clinicians; commonly 25–100 micrograms intravenously, repeated as needed with monitoring.
Usual dose in children
Specialist-calculated doses may be used during anesthesia; no general dose applies.
Common side effects
- Slow or stopped breathing
- Sleepiness, dizziness, or confusion
- Nausea and vomiting
- Low blood pressure or slow heartbeat
Important warnings
- Can cause fatal breathing problems, especially with alcohol or sedatives.
- Use only in monitored clinical settings when given by injection.
- Repeated use can cause dependence; abrupt stopping may cause withdrawal.
- High risk of overdose; keep away from others.
Pregnancy
May cause newborn breathing problems or withdrawal after use near delivery; use only when clinically necessary.
Breastfeeding
May enter breast milk and cause infant sleepiness or breathing problems; clinical guidance is needed.
Interactions
- Alcohol, benzodiazepines, and other sedatives increase breathing risks.
- Other opioids can increase sedation and overdose risk.
- Some medicines affecting CYP3A4 can raise or lower fentanyl levels.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.