Consumer medicine information

Fentanyl B. Braun Injection



Brand name

B. Braun Fentanyl Solution for injection

Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Fentanyl B. Braun Injection.

What is in this leaflet

This leaflet answers some common questions about B. BRAUN FENTANYL injection. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you receiving B. BRAUN FENTANYL against the benefits this medicine is expected to have for you.

If you have any concerns about receiving SUBLIMAZE, ask your doctor or pharmacist.

Keep this leaflet with your medicine. You may need to read it again.

What B. BRAUN FENTANYL is used for

B. BRAUN FENTANY L injection is used to provide short-term pain relief and to help anaesthesia when you have an operation. It is a strong painkiller for use in hospitals.

B. BRAUN FENTANYL injection contains a medicine called fentanyl. It belongs to a group of medicines known as narcotic analgesics or opioids. Fentanyl relieves pain by blocking the nerves in the brain that recognise pain messages from the body.

Your doctor may have prescribed B. BRAUN FENTANYL for another reason. Ask your doctor if you have any questions about why this medicine has been prescribed for you.

B. BRAUN FENTANYL may be addictive. Addiction is unlikely in patients who receive it under medical supervision.

Before you are given B. BRAUN FENTANYL

When you must not be given B. BRAUN FENTANYL

B. BRAUN FENTANYL should not be used:

  • if you have an allergy to B. BRAUN FENTANYL, other strong pain killers or any of the ingredients. See Product Description at the end of this leaflet for a list of ingredients.
  • if you suffer from asthma or if you are particularly prone to breathing difficulties (for example, in the case of head injury, coma or brain tumour).
  • if you have taken a type of medicine known as monoamine oxidase inhibitors (MAOIs) within the last 14 days. These include phenelzine, moclobemide and tranylcypromine (for depression) and selegiline (for Parkinson's disease).
  • if you suffer from a condition known as myasthenia gravis which causes constant weakness of muscles.
  • in children less than two years old.

B. BRAUN FENTANYL should not be used if the packaging is torn or shows signs of tampering. It should not be used beyond the expiry date (month and year) printed on the pack.

Before you are given B. BRAUN FENTANYL

You must tell your doctor if:

  • you are pregnant or planning to become pregnant
  • you are breast feeding or wish to breastfeed. Fentanyl is excreted in human milk
  • you have a lung disease or breathing problems
  • you have a brain disorder
  • you know you have a slow or irregular heart beat
  • you have or have ever had kidney or liver diseases
  • you are an alcoholic
  • you have an underactive thyroid gland.

If you have not told your doctor or pharmacist about any of the above, tell them before you are given SUBLIMAZE.

Your doctor will decide whether or not to treat you with B. BRAUN FENTANYLor whether to adjust the dose or alter your treatment.

Taking other medicines

Tell your doctor or pharmacist if you are taking any other medicines, including medicines you can buy without a prescription from a pharmacy, supermarket or health food shop.

In particular, tell your doctor or pharmacist if you are taking any of the following:

  • medicines which make you feel drowsy or slow to react, such as, sleeping tablets, tranquillisers or strong pain-killers.
  • medicines for mental disorders or a group of medicine called monoamine oxidase inhibitors (MAOIs). These include phenelzine, moclobemide and tranylcypromine (for depression) and selegiline (for Parkinson's disease). They should be stopped for 14 days before B. BRAUN FENTANYL is given.
  • medicines for depression known as selective serotonin re-uptake inhibitors (SSRIs) or serotonin norepinephrine re-uptake inhibitors (SNRIs) These include fluoxetine, paroxetine, sertraline and venlafaxine
  • ritonavir (a protease inhibitor used to treat HIV).

These medicines may be affected by B. BRAUN FENTANYL or may affect how well B. BRAUN FENTANYL works. Your doctor or pharmacist can tell you what to do if you are taking any of these medicines.

Effect on driving and operating machinery
B. BRAUN FENTANYL can have a negative effect on your alertness and ability to drive and operate machinery. Do not drive or operate machinery until your doctor says it is safe.

Effect of alcohol
B. BRAUN FENTANYL can increase the effect of alcohol.


How it is given

B. BRAUN FENTANYL is given by your doctor as an injection into a muscle or a vein. Your doctor will decide how much B. BRAUN FENTANYL you need. This will depend on your age, body weight, medical conditions and history.

The usual dose of B. BRAUN FENTANYL ranges from 25 micrograms to 100 micrograms depending on what it is being used for. Repeat doses may be given in some cases.

If you are elderly, you may be given a lower dose of B. BRAUN FENTANYL.

Children 2 to 12 years old
The usual dose ranges from 20 micrograms to 30 micrograms per 10 kg of body weight.

B. BRAUN FENTANYL is not recommended for use in children under 2 years.

If you are given too much (overdose)

Immediate medical care is required. The main symptom is markedly weakened breathing.

If you think you or anybody else has taken too much SUBLIMAZE, contact your doctor, pharmacist or the Poisons Information Centre who will advise you what to do.

You can contact the Poisons Information Centre by dialing:

  • Australia: 13 11 26

While you are given B. BRAUN FENTANYL

Things you must do

  • Always follow your doctor's instructions carefully.
  • Tell your doctor if you become pregnant.
  • Tell your doctor or pharmacist if you are about to start taking a new medicine.

Things you must not do

  • Do not use B. BRAUN FENTANYL to treat any other complaint unless your doctor says so.
  • Do not give this medicine to anyone else, even if their symptoms seem similar to yours.

If you do not understand the instructions provided with this medicine, ask your doctor or pharmacist for help.

Side Effects

All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some side effects. Do not be alarmed by this list of possible side effects. You may not experience any of them.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor immediately if you notice any of the following as you may need urgent medical care:

  • difficulty in breathing (abnormally slow and/or weak breathing or increased breathing rate or a temporary cessation of breathing)
  • muscle stiffness or involuntary muscle movements, including slow, stiff or jerking movements
  • slow, fast or irregular heart beat or cardiac arrest
  • a feeling of choking which is caused by the spasm of the muscles around the voice box
  • allergic reactions such as skin rash, redness and swelling of the face, neck or throat.
  • severe drowsiness
  • convulsions
  • loss of consciousness

Tell your doctor if you experience any of the following:

  • dizziness
  • low or high or variable blood pressure which may cause headache, weakness or dizziness
  • hiccups
  • blurred vision
  • nausea, vomiting
  • excessive sweating
  • itching
  • an unusual sense of well being
  • sedation
  • headaches
  • post-operative confusion or agitation
  • neurological or airway complications of anaesthesia
  • vein pain or inflammation
  • chills or lowered body temperature
  • visual disturbance

Other side effects not listed above may also occur in some people. Tell your doctor if you notice any other effects.

After you have been given B. BRAUN FENTANYL

Keep B. BRAUN FENTANYL injection in the pack until use. Protect from light.

Keep B. BRAUN FENTANYL injection in a cool dry place where the temperature stays below 30°C.

Keep your medicines where children cannot reach them. A locked cupboard at least one-and-a-half metres (1.5 m) above the ground is a good place to store medicines.

Do not store B. Braun Fentanyl, or any other medicine, in the bathroom or near a sink. Do not leave medicines in the car or on window sills.

Heat and dampness can destroy some medicines.

Product Description

What it looks like

B. BRAUN FENTANYL injection is a clear, colourless solution. It is available in 2 mL, 5 mL and 10 mL glass ampoules.

Registration numbers

100 micrograms/2 mL ampoule: AUST R XXXXX

250 micgrograms/5 mL ampoule: AUST R XXXXX

500 micrograms/10 mL ampoule: AUST R XXXXX


B. BRAUN FENTANYL contains 50 micrograms of fentanyl per mL (as fentanyl citrate). The 2 mL ampoule contains 100 micrograms of fentanyl, the 5 mL ampoule contains 250 micrograms of fentanyl, and the 10 mL ampoule contains 500 micrograms of fentanyl.

B. BRAUN FENTANYL also contains sodium chloride and water.


B. Braun Australia Pty Ltd
17 Lexington Drive
Bella Vista NSW 2153

This leaflet was prepared in August 2014.


Brand name

B. Braun Fentanyl Solution for injection

Active ingredient





Name of the medicine

Fentanyl (as citrate).


Sodium chloride 9 mg/mL and water for injections q.s. to 2 mL, 5 mL and 10 mL for the 2 mL, 5 mL and 10 mL fill volume ampoules, respectively.


Chemical name: N-phenyl-N-[1-(2-phenylethyl) piperidin-4-yl]propanamide dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate. Molecular formula: C22H28N2O.C6H8O7. MW: 528.6 (fentanyl citrate); 336.5 (fentanyl). CAS: 990-73-8 (fentanyl citrate); 438-38-7 (fentanyl). Fentanyl citrate is a 4-anilinopiperidine derivative. It is a white to almost white powder with a pKa of 8.4. B. Braun Fentanyl for injection contains fentanyl 50 microgram per mL (as fentanyl citrate). It is a sterile, clear, colourless solution practically free from visible particles with a pH 4.0-6.5.



Fentanyl is a potent narcotic analgesic with a rapid onset and short duration of action. The principal actions of therapeutic value are analgesia and sedation. At a dose of 100 microgram (2 mL), the analgesic activity of fentanyl is approximately equivalent to 10 mg of morphine or 75 mg of pethidine. Fentanyl differs from morphine by its short duration of analgesic activity, lack of emetic activity, and minimal hypotensive activity.
The action of fentanyl is qualitatively similar to those of morphine and pethidine, i.e. analgesia, euphoria, miosis, bradycardia, respiratory depression, bronchoconstriction, muscle rigidity and suppression of cough reflexes. These effects can be reversed by specific narcotic antagonists, e.g. naloxone. As with morphine, fentanyl induced bradycardia from vagal stimulation is blocked or reversed by atropine. Alterations in respiratory rate and alveolar ventilation, associated with narcotic analgesics may last longer than the analgesic effect. As the dose of the narcotic is increased, the decrease in pulmonary exchange becomes greater. Larger doses may produce apnoea. The behavioural effects in mice of fentanyl and morphine are similar, and with toxic doses death is due to respiratory depression. The respiratory depressant properties of fentanyl appear to be due to a central effect by decreasing the sensitivity of the respiratory centre to carbon dioxide. In an experiment in cats, no effect on neuromuscular transmission was observed in the presence of severe respiratory depression.
Histamine assays and skin wheal testing in man, as well as in vivo testing in dogs, indicate that histamine release rarely occurs with fentanyl. Experiments in dogs, have shown that intravenously administered fentanyl at doses 2-4 times the recommended human dose, had minimal effect on blood pressure and heart rate. Much higher doses of fentanyl citrate, ranging from 100-400 microgram/kg, produce an immediate fall in blood pressure, followed by partial recovery, and a sustained hypotensive effect lasting up to 30 minutes.
Fentanyl produces a minimum of cortical depression, and it is suggested that it exerts its action by filling receptor sites located in the thalamus, midbrain, and spinal cord. A specific narcotic antagonist, e.g. naloxone, produces reversal of respiratory, cardiovascular, miotic, and motor incoordination effects, as well as analgesia, euphoria, and sedation. Rigidity of the diaphragm and intercostal muscles can be eliminated by succinylcholine. Cholinergic effects, e.g. bradycardia, are reversed by atropine.


The pKa of fentanyl is 8.4.
The onset of action of fentanyl is almost immediate when the drug is given intravenously. However, the maximal analgesic and respiratory depressant effect may not be noted for several minutes. The usual duration of action of analgesic effect is 30 to 60 minutes after a single I.V. dose of up to 100 microgram. Following intramuscular administration, the onset of action is from 7 to 8 minutes and the duration of action is 1 to 2 hours.
As with longer acting narcotic analgesics, the duration of the respiratory depressant effect of fentanyl may be longer than the analgesic effect. The following observations have been reported concerning altered respiratory response to CO2 stimulation following administration of fentanyl to man.
Diminished sensitivity to CO2 stimulation may persist longer than depression or respiratory rate.
Fentanyl frequently slows the respiratory rate, but this effect is seldom noted for longer than 30 minutes regardless of the dose administered. Altered sensitivity to CO2 stimulation has been demonstrated for up to four hours following a single intravenous dose of 600 microgram (12 mL) fentanyl to healthy volunteers. Duration and degree of respiratory depression is dose related. The peak respiratory depressant effect of a single intravenous dose of fentanyl is noted 5 to 15 minutes following injection. (See also Precautions concerning respiratory depression.)


After intravenous injection, fentanyl plasma concentrations fall rapidly, with sequential distribution half-lives of 1 minute and 18 minutes and a terminal elimination half-life of 475 minutes. Fentanyl has a Vc (volume of distribution of the central compartment) of 13 L, and a total Vdss (distribution volume at steady state) of 339 L. The total blood binding of fentanyl is about 83% (comprised of plasma protein binding about 43% and red blood cell binding about 40%).


Fentanyl is extensively metabolised by the liver and it has a high hepatic extraction ratio (0.8-1.0). Consequently, the hepatic clearance of fentanyl approaches hepatic blood flow. In humans, in vitro experiments have demonstrated that fentanyl is metabolised mainly by cytochrome P450 3A4 (CYP3A4) to norfentanyl via oxidative N-dealkylation.


Approximately 75% of the administered dose is excreted in the urine within 72 hours and only 8.4% of the dose recovered in urine is present as unchanged drug.

Special populations.


Pharmacokinetic information in children is limited and obtained from different sources. CYP3A4 activity is very low at birth but increases after birth to reach 30-40% of adult levels at 1 month of age. The clearance and volume of distribution adjusted for bodyweight are higher in infants and children than in adults after I.V. administration of fentanyl. The terminal elimination half-life is longer in newborn infants.
After intravenous administration, the plasma protein binding of fentanyl in newborn infants is lower than in adults. It is higher in preterm neonates (77%) than in those born at term (approximately 62%).
See Table 1.

Adult patients with burns.

An increase in median clearance of 45% together with a larger volume of distribution results in lower fentanyl plasma concentrations. This may require an increased dose of fentanyl.


B. Braun Fentanyl injection is indicated for the following.
Analgesic action of short duration during anaesthetic periods, premedication, induction and maintenance, and in the immediate postoperative period (recovery room) as the need arises;
use as a narcotic analgesic supplement in general and regional anaesthesia;
administration with a neuroleptic such as droperidol injection as an anaesthetic premedication, for the induction of anaesthesia, and as an adjunct in the maintenance of general and regional anaesthesia.


B. Braun Fentanyl is contraindicated in patients with known intolerance to fentanyl, any of the components of B. Braun Fentanyl or other morphinomimetics.
Fentanyl should not be administered to children two years of age or younger, because safe conditions for use have not been established (see Precautions, Paediatric use). B. Braun Fentanyl should not be administered to patients suffering from bronchial asthma. As for any narcotic analgesic, it should not be used in patients who may be particularly susceptible to respiratory depression, such as comatose patients who may have a head injury or brain tumour (see Precautions). Severe and unpredictable potentiation by MAO inhibitors has been reported with narcotic analgesics.
There is no evidence that fentanyl is potentiated by MAO inhibitors, but since such potentiation is found with other narcotic analgesics, the use of fentanyl in patients who have received MAO inhibitors within 14 days is not recommended (see Interactions with Other Medicines). B. Braun Fentanyl may cause thoracic muscle rigidity upon intravenous administration. Therefore, the need for reversal with muscle relaxants contraindicates its use in patients with a history of myasthenia gravis.


Drug dependence.

Fentanyl can produce drug dependence of the morphine type and therefore has the potential for being abused. Fentanyl may be habit forming.
Patients on chronic opioid therapy or with a history of opioid abuse may require higher doses.

Hypoventilation (respiratory depression).

Profound analgesia is accompanied by marked respiratory depression, which can persist or recur in the postoperative period. Hyperventilation during anaesthesia may alter the patient’s responses to CO2, thus affecting respiration postoperatively. Therefore, patients should remain under appropriate surveillance.
Fentanyl should be used with caution in patients with severe impairment of pulmonary function because of the possibility of respiratory depression, e.g. patients with chronic obstructive pulmonary disease, patients with decreased respiratory reserve, or any patient with potentially compromised respiration. In such patients, narcotics may additionally decrease respiratory drive and increase airway resistance. During anaesthesia, this can be managed by assisted or controlled respiration.
Respiratory depression caused by narcotic analgesics can be reversed by narcotic antagonists. Appropriate surveillance should be maintained because the duration of respiratory depression of doses of fentanyl employed during anaesthesia may be longer than the duration of narcotic antagonist action. Consult individual prescribing information (naloxone) before employing narcotic antagonists. The use of a narcotic antagonist will also reverse analgesia. See also discussion of narcotic antagonists in Overdosage.
Respiratory depression is more likely to occur with intravenous administration if a dose is given too rapidly and it rarely occurs with intramuscular administration.
Resuscitative equipment and a narcotic antagonist should be readily available to manage apnoea.

Muscle rigidity.

Fentanyl may cause muscle rigidity, particularly involving the muscles of respiration. This effect is related to the speed of injection and its incidence can be reduced by a slow intravenous injection (ordinarily sufficient for lower doses) premedication with benzodiazepines and the use of muscle relaxants.
Once the effect occurs, it is managed by the use of assisted or controlled respiration and, if necessary, by a neuromuscular blocking agent compatible with the patient's condition.
Nonepileptic (myo)clonic movements can occur.

Head injuries and increased intracranial pressure.

Fentanyl should be used with caution in patients who may be particularly susceptible to respiratory depression, such as comatose patients who may have a head injury or brain tumour. In addition, fentanyl may obscure the clinical course of patients with a head injury.
The use of rapid bolus injections of opioids should be avoided in patients with compromised intracerebral compliance; in such patients the transient decrease in the mean arterial pressure has occasionally been accompanied by a short lasting reduction of the cerebral perfusion pressure.

Cardiac effects.

Fentanyl may produce bradycardia and possibly cardiac arrest if the patient has received an insufficient amount of anticholinergic, or when fentanyl is combined with nonvagolytic muscle relaxants. Bradycardia may be treated with atropine. However, fentanyl should be used with caution in patients with cardiac bradyarrhythmias.
Opioids may induce hypotension, especially in hypovolaemic patients. Appropriate measures to maintain a stable arterial pressure should be taken.

Serotonin syndrome.

Caution is advised when fentanyl is coadministered with drugs that affect the serotonergic neurotransmitter systems.
The development of a potentially life threatening serotonin syndrome may occur with the concomitant use of serotonergic drugs such as selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs), and with drugs which impair metabolism of serotonin (including monoamine oxidase inhibitors [MAOIs]). This may occur within the recommended dose. Serotonin syndrome may include mental status changes (e.g. agitation, hallucinations, coma), autonomic instability (e.g. tachycardia, labile blood pressure, hyperthermia), neuromuscular abnormalities (e.g. hyperreflexia, incoordination, rigidity), and/or gastrointestinal symptoms (e.g. nausea, vomiting, diarrhea).
If serotonin syndrome is suspected, rapid discontinuation of B. Braun Fentanyl should be considered.


As has been observed with all narcotic analgesics, episodes suggestive of sphincter of Oddi spasm may occur with fentanyl.
Vital signs should be monitored carefully.

Effects on fertility.

Impairment of fertility has been observed in female rats given fentanyl 160 microgram/kg/day subcutaneously (no effect dose not established) or 400 microgram/kg/day intravenously (no effect dose 100 microgram/kg/day). Fertility in male rats was unaffected at 400 microgram/kg/day intravenously.

Use in pregnancy.

(Category C)
There are no adequate data from the use of fentanyl in pregnant women. Intramuscular or intravenous administration during childbirth (including caesarean section) is not recommended because fentanyl crosses the placenta (fetal blood concentrations about 40% of maternal blood concentrations) and the fetal respiratory centre is particularly sensitive to opiates. If fentanyl is nevertheless administered, an antidote for the child should always be at hand.
In pregnant rats, fentanyl is embryocidal as evidenced by increased resorptions at doses of 30 microgram/kg/day intravenously or 160 microgram/kg/day or greater subcutaneously. Intravenous administration to rats at 30 microgram/kg/day during organogenesis was associated with prolonged delivery time and increased postnatal mortality of offspring. There was no effect on embryofetal development when rats received subcutaneous fentanyl at doses up to 500 microgram/kg/day throughout gestation, and no evidence of teratogenicity in rabbits administered fentanyl at intravenous doses up to 400 microgram/kg/day during organogenesis. The potential risk for humans is unknown.

Use in lactation.

Fentanyl is excreted into human milk and may cause sedation/ respiratory depression in the newborn/ infant. Therefore, breastfeeding is not recommended for 24 hours following the administration of fentanyl. The risk/ benefit of breastfeeding following fentanyl administration should be considered.

Paediatric use.

The safety of fentanyl in children younger than two years of age has not been established.

Use in the elderly or debilitated patients.

It is recommended to reduce the dosage of B. Braun Fentanyl in the elderly and in debilitated patients. Opioids should be titrated with caution in patients with any of the following conditions: uncontrolled hypothyroidism, pulmonary disease, decreased respiratory reserve, alcoholism, impaired hepatic or renal function. Such patients also require prolonged postoperative monitoring.


Fentanyl showed no evidence of genotoxic potential in assays for gene mutations (Ames reverse mutation test, mouse lymphoma thymidine kinase assay), chromosomal damage (Chinese hamster ovary cells, mouse micronucleus test) and other genotoxic effects (unscheduled DNA synthesis in rat hepatocytes, mammalian cell transformation assay). The genotoxic potential of fentanyl is considered to be low.


In a two year carcinogenicity study in rats, fentanyl was not associated with an increased incidence of tumours at subcutaneous doses up to 33 microgram/kg/day in males or 100 microgram/kg/day in females, which were the respective maximum tolerated doses.

Effects on ability to drive and use machines.

Patients should only drive or operate a machine if sufficient time has elapsed after the administration of B. Braun Fentanyl.


Effects of other medicines on fentanyl.

CNS depressants.

Drugs such as CNS depressants, barbiturates, benzodiazepines, neuroleptics, narcotics, alcohol and general anaesthetics, will have additive or potentiating effects with fentanyl. When patients have received such drugs, the dose of fentanyl required will be less than usual. Postoperative narcotics including fentanyl and other depressants should be given initially in reduced doses, as low as ¼ to 1/3 of those usually recommended. As with other narcotics, the respiratory depressant effect of fentanyl persists longer than the measured analgesic effect. The total dose of all narcotic analgesics should be considered before ordering narcotic analgesics during recovery from anaesthesia.

Conduction anaesthesia.

Certain forms of conduction anaesthesia, such as spinal anaesthesia and some peridural anaesthetics, can alter respiration by blocking intercostal nerves. Through other mechanisms (see Pharmacology) fentanyl can also alter respiration. Therefore, when fentanyl is used to supplement these forms of anaesthesia, the anaesthetist should be familiar with the special properties of each drug (particularly with the widely differing durations of actions), the physiological alterations involved and be prepared to manage them in patients selected for these forms of anaesthesia.


When fentanyl is used with a neuroleptic such as droperidol, blood pressure may be altered and hypotension can occur. If this occurs, the possibility of hypovolaemia should also be considered and managed with appropriate parenteral fluid therapy. Repositioning the patient improves venous return to the heart and should be considered when operative conditions permit. Care should be exercised in moving and positioning patients because of the possibility of orthostatic hypotension. If volume expansion with fluids together with other countermeasures do not correct hypotension, the administration of pressor agents other than adrenaline should be considered. Because of the alpha-adrenergic blocking action of droperidol, adrenaline may paradoxically decrease the blood pressure in patients treated with droperidol. Pulmonary arterial pressure may also be decreased. This should be considered when interpreting pulmonary arterial pressure measurements as it might determine the final management of the patient. When droperidol is used with fentanyl and the EEG is used for postoperative monitoring, it may be found that the EEG pattern returns to normal slowly.

Monoamine oxidase inhibitors.

Severe and unpredictable potentiation by MAO inhibitors has been reported with narcotic analgesics. Since the safety of fentanyl in this regard has not been established, the use of fentanyl in patients who have received MAO inhibitors within 14 days is not recommended.

Serotonergic drugs.

Coadministration of fentanyl with a serotonergic agent, such as a selective serotonin reuptake inhibitor (SSRI) or a serotonin norepinephrine reuptake inhibitor (SNRI) or a monoamine oxidase inhibitor (MAOI), may increase the risk of serotonin syndrome, a potentially life threatening condition.

CYP3A4 metabolised agents.

Fentanyl is primarily metabolised in the liver via CYP3A4 enzyme and has a high hepatic extraction ratio. Therefore, hepatic blood flow rather than enzyme activity is the main determinant of fentanyl clearance. Theoretically, coadministration of CYP3A4 enzyme inhibitors should cause only a small increase in plasma concentrations of fentanyl.
Oral administration of itraconazole (a potent inhibitor of CYP3A4) at 200 mg/day for 4 days did not have a statistically significant effect on the pharmacokinetics of fentanyl at a dose of 3 microgram/kg given as a single intravenous infusion over 2 minutes. Coadministration of fluconazole or voriconazole and fentanyl may result in an increased exposure to fentanyl.
Ritonavir is a highly potent inhibitor of CYP3A4. Oral administration of ritonavir in healthy volunteers, at 200-300 mg t.d.s. for 2 days, significantly inhibits the metabolism of fentanyl at a dose of 5 microgram/kg, given as a single intravenous infusion over 2 minutes. Ritonavir decreased the clearance of fentanyl by 67%, prolonged the half-life of fentanyl by 100% and increased AUC (0 to infinity) by 174%. Ritonavir had no significant effect on the steady-state volume of distribution of fentanyl. When fentanyl is given continuously with ritonavir, the dose of fentanyl should be reduced in order to lower the risk for severe and prolonged respiratory depression. When fentanyl is given as a single dose concomitantly with ritonavir, the duration of respiratory monitoring should be increased and the dose of fentanyl may need to be reduced.
There are no data on the in vivo interactions between fentanyl and other drugs inhibiting CYP3A4 (e.g. ketoconazole, erythromycin, diltiazem and cimetidine).

Effects of fentanyl on other medicines.

Following the administration of fentanyl, the dose of other CNS depressant drugs should be reduced. For etomidate, the total plasma clearance is decreased by 2.7-fold and volume of distribution is decreased by a factor 2.4 while half-life increased by 1.2 times when administered with fentanyl. Simultaneous administration of fentanyl and intravenous midazolam results in an increase in the terminal plasma half-life and a reduction in the plasma clearance of midazolam. When these drugs are coadministered with fentanyl their dose may need to be reduced.

Adverse Effects

Clinical trial data.

The safety of fentanyl was evaluated in 376 subjects who participated in 20 clinical trials evaluating fentanyl used as an anaesthetic. These subjects took at least one dose of fentanyl and provided safety data. Adverse drug reactions (ADRs), as identified by the investigator, reported for ≥ 1% of fentanyl treated subjects in these studies are shown in Table 2.

Additional ADRs that occurred in < 1% of fentanyl treated subjects in the 20 clinical trials are listed below.

Psychiatric disorders.

Euphoric mood.

Nervous system disorders.


Vascular disorders.

Blood pressure fluctuation, phlebitis.

Respiratory, thoracic and mediastinal disorders.

Hiccups, hyperventilation.

General disorders and administration site conditions.

Chills, hypothermia.

Injury, poisoning and procedural complications.

Agitation postoperative, procedural complication, airway complication of anaesthesia.

Postmarketing data.

Adverse drug reactions first identified during postmarketing experience with fentanyl are listed below, based on spontaneous reporting rates. The frequencies are provided according to the following convention.
Very common: ≥ 1/10; common: ≥ 1/100 and < 1/10; uncommon: ≥ 1/1,000 and < 1/100; rare: ≥ 1/10,000 and < 1/1,000; very rare: < 1/10,000, including isolated reports.

Immune system disorders.

Very rare: hypersensitivity (such as anaphylactic shock, anaphylactic reaction, urticaria).

Nervous system disorders.

Very rare: convulsions, loss of consciousness, myoclonus.

Cardiac disorders.

Very rare: cardiac arrest (also see Precautions).

Respiratory, thoracic and mediastinal disorders.

Very rare: respiratory depression (also see Precautions).

Skin and subcutaneous tissue disorders.

Very rare: pruritus.
When a neuroleptic is used with fentanyl, the following adverse reactions may be observed: chills and/or shivering; restlessness, postoperative hallucinatory episodes; and extrapyramidal symptoms.

Dosage and Administration

Dosage should be individualised. Some of the factors to be considered in determining the dose are: age, bodyweight, physical status, underlying pathological condition, use of other drugs, type of anaesthesia to be used, and the surgical procedure involved.
The initial dose should be reduced in the elderly and in debilitated patients. The effect of the initial dose should be taken into account in determining supplemental doses.
Vital signs should be monitored routinely.
For single use in one patient on one occasion only. Discard any remaining residue. Contains no antimicrobial preservative.

Usual dosage in adults.


(To be appropriately modified in the elderly, debilitated and those who have received other depressant drugs.)
50 to 100 microgram (1 to 2 mL) may be administered intramuscularly 30 to 60 minutes prior to surgery.

Adjunct to general anaesthesia.


50 to 100 microgram (1 to 2 mL) may be administered initially intravenously and may be repeated at 2 to 3 minute intervals until the desired effect is achieved. A reduced dose as low as 25 to 50 microgram (0.5 to 1 mL) is recommended in elderly and poor risk patients.


25 to 50 microgram (0.5 to 1 mL) may be administered intravenously or intramuscularly when movement and/or changes in vital signs indicate surgical stress or lightening of analgesia.

Adjunct to regional anaesthesia.

50 to 100 microgram (1 to 2 mL) may be administered intramuscularly or slowly intravenously when additional analgesia is required.

Postoperatively (recovery room).

50 to 100 microgram (1 to 2 mL) may be administered intramuscularly for the control of pain, tachypnoea, and emergence delirium. The dose may be repeated in one or two hours as needed.

Usual dosage in children.

For induction and maintenance in children 2-12 years of age, a reduced dose as low as 20 to 30 microgram (0.4 to 0.6 mL) per 10 kg is recommended. (See Precautions for use of B. Braun Fentanyl with other CNS depressants and in patients with altered response.)


The oral LD50 for fentanyl in rats is 18.0 mg/kg. The intravenous LD50 is 2.3 mg/kg, and the intramuscular LD50 is 1.0 mg/kg in rats. The toxic dose in man is unknown.
For information on the management of overdose, contact the Poisons Information Centre on 131 126 (Australia).

Signs and symptoms.

The manifestations of fentanyl overdosage are an extension of its pharmacological actions. In sufficient overdosage, fentanyl would produce narcosis, which may be preceded by marked skeletal muscle rigidity. Cardiorespiratory depression accompanied by cyanosis occurs, followed by a fall in body temperature, circulatory collapse, coma and death.


In the presence of hypoventilation or apnoea, oxygen should be administered and respiration should be assisted or controlled as indicated. A patent airway must be maintained. An oropharyngeal airway or endotracheal tube might be indicated. If depressed respiration is associated with muscular rigidity, an intravenous neuromuscular blocking agent might be required to facilitate assisted or controlled respiration.
A specific narcotic antagonist, such as naloxone, should be available for use as indicated to manage respiratory depression. This does not preclude the use of more immediate countermeasures. The duration of respiratory depression following overdosage of fentanyl may be longer than the duration of narcotic antagonist action. Consult the package insert of the individual narcotic antagonists for details about use. The patient should be carefully observed for 24 hours. Body warmth and adequate fluid intake should be maintained. If hypotension occurs, and is severe or persists, the possibility of hypovolaemia should be considered and managed with appropriate parenteral fluid therapy. The use of a narcotic antagonist will also reverse analgesia.


Solution for injection (≡ fentanyl 50 microgram/mL, sterile, clear, colourless), 100 microgram/2 mL; 250 microgram/5 mL*; 500 microgram/10 mL: 10’s (ampoules).
For hospital use only.
*Not currently marketed in Australia.


Protect from light. Do not freeze. Ampoules should be removed only for immediate use.

Poison Schedule