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Fentanyl: Indications, Dosing, Side Effects and Interactions
Fentanyl clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 4 min read
Fentanyl: Indications, Dosing, Side Effects and Interactions
Fentanyl clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Chronic severe pain currently treated with a weak opioid analgesic (administered on expert advice) for fentanyl**
- **Child 16-17 years** (By transdermal application): Initially 12 micrograms/hour every 72 hours, when starting, evaluation of the analgesic effect should not be made before the system has been worn for 24 hours (to allow for the gradual increase in plasma-fentanyl concentration)-previous analgesic therapy should be phased out gradually from time of first patch application, dose should be adjusted at 72 hour intervals in steps of 12-25 micrograms/hour if necessary. After a dose increase, the system should be worn through two 72-hour applications before any further increase in dose, more than one patch may be used at a time (but applied at the same time to avoid confusion)-consider additional or alternative analgesic therapy if dose required exceeds 300 micrograms/hour (important: it takes 20 hours or more for the plasma-fentanyl concentration to decrease by 50%-replacement opioid therapy should be initiated at a low dose and increased gradually). For further information including opioid dose conversion and the management of breakthrough pain, see Pain management with opioids under Prescribing in palliative care.
**Chronic severe pain currently treated with a strong opioid analgesic (administered on expert advice) for fentanyl**
- **Child 2-17 years** (By transdermal application): Initial dose based on previous 24-hour opioid requirement-consult product literature, for evaluating analgesic efficacy and dose increments-consult product literature, for conversion from long term oral morphine to transdermal fentanyl, see Pain management with opioids under Prescribing in palliative care.
**Spontaneous respiration: analgesia and enhancement of anaesthesia, during operation for fentanyl**
- **Child 1 month-11 years** (By intravenous injection): Initially 1-3 micrograms/kg, then 1 microgram/kg as required, dose to be administered over at least 30 seconds.
- **Child 12-17 years** (By intravenous injection): Initially 50-100 micrograms (max. per dose 200 micrograms), dose maximum on specialist advice, then 25-50 micrograms as required, dose to be administered over at least 30 seconds.
**Assisted ventilation: analgesia and enhancement of anaesthesia during operation for fentanyl**
- **Neonate** (By intravenous injection): Initially 1-5 micrograms/kg, then 1-3 micrograms/kg as required, dose to be administered over at least 30 seconds.
- **Child 1 month-11 years** (By intravenous injection): Initially 1-5 micrograms/kg, then 1-3 micrograms/kg as required, dose to be administered over at least 30 seconds.
- **Child 12-17 years** (By intravenous injection): Initially 1-5 micrograms/kg, then 50-200 micrograms as required, dose to be administered over at least 30 seconds.
**Assisted ventilation: analgesia and respiratory depression in intensive care for fentanyl**
- **Neonate** (Initially by intravenous injection): Initially 1-5 micrograms/kg, then (by intravenous infusion) 1.5 micrograms/kg/hour, adjusted according to response.
- **Child** (Initially by intravenous injection): Initially 1-5 micrograms/kg, then (by intravenous infusion) 1-6 micrograms/kg/hour, adjusted according to response.
**Breakthrough pain in patients receiving opioid therapy for chronic cancer pain (administered on expert advice) for fentanyl**
- **Child 16-17 years** (By buccal administration using lozenges): Initially 200 micrograms, dose to be given over 15 minutes, then 200 micrograms after 15 minutes if required, no more than 2 dose units for each pain episode; if adequate pain relief not achieved with 1 dose unit for consecutive breakthrough pain episodes, increase the strength of the dose unit until adequate pain relief achieved with 4 lozenges or less daily, if more than 4 episodes of breakthrough pain each day, adjust background analgesia.
Interactions
**Severe interactions:**
- Possible toxicity with phenytoin on stopping primidone); stiripentol, tiagabine, valproic acid, zonisamide.
- Administration of IV parecoxib 40 mg had no significant effect on the pharmacokinetics of either IV fentanyl or IV alfentanil (CYP3A4 substrates).
**Other interactions (23):**
- Analgesics/Anaesthetics (Alfentanil, Fentanyl, Methadone): Coadministration of fluconazole may cause decreased clearance of alfentanil, fentanyl or methadone and subsequent increased or prolonged...
- Fentanyl The total plasma clearance and volume of distribution of etomidate is decreased by a factor of 2 to 3 without a change in half-life when administered with fentanyl intravenously.
- When etomidate is co-administered with fentanyl intravenously, the dose may need to be reduced.
- Opiates and benzodiazepines Patients anaesthetized with different concentrations of desflurane and receiving increasing doses of fentanyl or midazolam showed a reduction in anaesthetic requirements...
- Effect of Fentanyl or Midazolam on Desflurane MAC Concentration* (%) of desflurane in O 2 % Reduction in Concentration No Fentanyl 6.33- 6.35 - Fentanyl (3 g / kg) 3.12-3.46 46-51 Fentanyl (6 g /...
- Therefore, caution should be exercised when mifepristone is administered with drugs that are CYP3A4 substrates and have narrow therapeutic range, such as cyclosporine, tacrolimus, sirolimus,...
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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