4.1. Therapeutic indications

Remifentanil is indicated as an analgesic agent for use during induction and/or maintenance of general anaesthesia under close supervision.

Remifentanil is indicated for provision of analgesia and sedation in mechanically ventilated intensive care patients 18 years of age and over.

4.2. Posology and method of administration

Remifentanil should be administered only in a setting fully equipped for the monitoring and support of respiratory and cardiovascular function and by persons specifically trained in the use of anaesthetic drugs and the recognition and management of the expected adverse effects of potent opioids, including respiratory and cardiac resuscitation. Such training must include the establishment and maintenance of a patent airway and assisted ventilation.

Continuous infusions of remifentanil must be administered by a calibrated infusion device into a fast flowing IV line or via a dedicated IV line. This infusion line should be connected at, or close to, the venous cannula and primed, to minimise the potential dead space (see section 6.6 for additional information, including tables with examples of infusion rates by body weight to help titrate remifentanil to the patient's anaesthetic needs).

Remifentanil may also be given by target controlled infusion (TCI) with an approved infusion device incorporating the Minto pharmacokinetic model with covariates for age and lean body mass (LBM).

Care should be taken to avoid obstruction or disconnection of infusion lines and to adequately clear the lines to remove residual remifentanil after use (see section 4.4).

Remifentanil is for intravenous use only and must not be administered by epidural or intrathecal injection (see section 4.3).

Dilution

Remifentanil may be further diluted after reconstitution (see section 6.4 and 6.6 for storage conditions of the reconstituted/diluted product and the recommended diluents).

For manually-controlled infusion remifentanil can be diluted to concentrations of 20 to 250 micrograms/ml (50 micrograms/ml is the recommended dilution for adults and 20 to 25 micrograms/ml for paediatric patients aged 1 year and over).

For TCI the recommended dilution of remifentanil is 20 to 50 micrograms/ml.

(See section 6.6 for additional information, including tables to help titrate remifentanil to the patient's anaesthetic needs).

4.2.1 General Anaesthesia

The administration of remifentanil must be individualised based on the patient's response. Specific dosing guidelines for patients undergoing cardiac surgery are provided in section 4.2.2 below.

4.2.1.1 Adults

Administration by Manually-Controlled Infusion

The following table summarises the starting infusion rates and dose range:

DOSING GUIDELINES FOR ADULTS

INDICATION

BOLUS INJECTION

(micrograms/kg)

CONTINUOUS INFUSION

(micrograms/kg/min)

Starting Rate

Range

Induction of anaesthesia

1(give over not less than 30 seconds)

0.5 to 1

_

Maintenance of anaesthesia in ventilated patients

• Nitrous oxide (66%)

0.5 to 1

0.4

0.1 to 2

• Isoflurane (starting dose 0.5MAC)

0.5 to 1

0.25

0.05 to 2

• Propofol (Starting dose 100 micrograms/kg/min)

0.5 to 1

0.25

0.05 to 2

When given by bolus injection at induction remifentanil should be administered over not less than 30 seconds.

At the doses recommended above, remifentanil significantly reduces the amount of hypnotic agent required to maintain anaesthesia. Therefore, isoflurane and propofol should be administered as recommended above to avoid an increase of haemodynamic effects such as hypotension and bradycardia (see Concomitant medication below).

Induction of anaesthesia: remifentanil should be administered with a standard dose of an hypnotic agent, such as propofol, thiopentone, or isoflurane, for the induction of anaesthesia. Administering remifentanil after an hypnotic agent will reduce the incidence of muscle rigidity. Remifentanil can be administered at an infusion rate of 0.5 to 1 micrograms/kg/min, with or without an initial slow bolus injection of 1 microgram/kg given over not less than 30 seconds. If endotracheal intubation is to occur more than 8 to 10 minutes after the start of the infusion of remifentanil, then a bolus injection is not necessary.

Maintenance of anaesthesia in ventilated patients: After endotracheal intubation, the infusion rate of remifentanil should be decreased, according to anaesthetic technique, as indicated in the above table. Due to the fast onset and short duration of action of remifentanil, the rate of administration during anaesthesia can be titrated upward in 25% to 100% increments or downward in 25% to 50% decrements, every 2 to 5 minutes to attain the desired level of mu-opioid response. In response to light anaesthesia, supplemental slow bolus injections may be administered every 2 to 5 minutes.

Anaesthesia in spontaneously breathing anaesthetised patients with a secured airway (e.g. laryngeal mask anaesthesia): In spontaneously breathing anaesthetised patients with a secured airway respiratory depression is likely to occur. Special care is needed to adjust the dose to the patient requirements and ventilatory support may be required. The recommended starting infusion rate for supplemental analgesia in spontaneously breathing anaesthetised patients is 0.04 micrograms/kg/min with titration to effect. A range of infusion rates from 0.025 to 0.1 micrograms/kg/min has been studied. Bolus injections are not recommended in spontaneously breathing anaesthetised patients.

Remifentanil should not be used as an analgesic in procedures where patients remain conscious or do not receive any airway support during the procedure.

Concomitant medication: remifentanil decreases the amounts or doses of inhaled anaesthetics, hypnotics and benzodiazepines required for anaesthesia (see section 4.5).

Doses of the following agents used in anaesthesia: isoflurane, thiopentone, propofol and temazepam have been reduced by up to 75% when used concurrently with remifentanil.

Guidelines for discontinuation/continuation into the immediate post-operative period: Due to the very rapid offset of action of remifentanil no residual opioid activity will be present within 5 to 10 minutes after discontinuation. For those patients undergoing surgical procedures where post-operative pain is anticipated, analgesics should be administered prior to discontinuation of remifentanil. Sufficient time must be allowed to reach the maximum effect of the longer acting analgesic. The choice of analgesic should be appropriate for the patient's surgical procedure and the level of post-operative care.

Care should be taken to avoid inadvertent administration of remifentanil remaining in IV lines and cannulae (see section 4.4).

In the event that longer acting analgesia has not been established prior to the end of surgery, remifentanil may need to be continued to maintain analgesia during the immediate post-operative period until longer acting analgesia has reached its maximum effect.

Guidance on provision of analgesia and sedation in mechanically ventilated intensive care patients is provided in section 4.2.3 below.

In patients who are breathing spontaneously, the infusion rate of remifentanil should initially be decreased to a rate of 0.1 micrograms/kg/min. The infusion rate may then be increased or decreased by not greater than 0.025 micrograms/kg/min every five minutes, to balance the patient's level of analgesia and respiratory rate. Remifentanil should only be used in a setting fully equipped for the monitoring and support of respiratory and cardiovascular function, under the close supervision of persons specifically trained in the recognition and management of the respiratory effects of potent opioids.

The use of bolus injections of remifentanil to treat pain during the post-operative period is not recommended in patients who are breathing spontaneously.

Administration by Target-Controlled Infusion

Induction and maintenance of anaesthesia in ventilated patients: remifentanil TCI should be used in association with an intravenous or inhalational hypnotic agent during the induction and maintenance of anaesthesia in ventilated adult patients (see the table in Dosing Guidelines For Adults under 4.2.1.1). In association with these agents, adequate analgesia for induction of anaesthesia and surgery can generally be achieved with target blood remifentanil concentrations ranging from 3 to 8 nanograms/ml. Remifentanil should be titrated to individual patient response. For particularly stimulating surgical procedures target blood concentrations up to 15 nanograms/ml may be required.

At the doses recommended above, remifentanil significantly reduces the amount of hypnotic agent required to maintain anaesthesia. Therefore, isoflurane and propofol should be administered as recommended above to avoid an increase of haemodynamic effects such as hypotension and bradycardia (see Table and Concomitant medication subsection in 4.2.1.1).

For information on blood remifentanil concentrations achieved with manually-controlled infusion see Table 6.

There are insufficient data to make recommendations on the use of TCI for spontaneous ventilation anaesthesia.

Guidelines for discontinuation/continuation into the immediate post-operative period: At the end of surgery when the TCI infusion is stopped or the target concentration reduced, spontaneous respiration is likely to return at calculated remifentanil concentrations in the region of 1 to 2 nanograms/ml. As with manually-controlled infusion, post-operative analgesia should be established before the end of surgery with longer acting analgesics (see Guidelines for discontinuation under Administration by manually-controlled infusion in section 4.2.1.1)

As there are insufficient data, the administration of remifentanil by TCI for the management of post-operative analgesia is not recommended.

4.2.1.2 Paediatric patients (1 to 12 years of age)

Co-administration of remifentanil and an intravenous anaesthetic agent for induction of anaesthesia has not been studied in detail and is therefore not recommended.

Remifentanil TCI has not been studied in paediatric patients and therefore administration of remifentanil by TCI is not recommended in these patients.

When given by bolus injection remifentanil should be administered over not less than 30 seconds. Surgery should not commence until at least 5 minutes after the start of the Remifentanil infusion, if a simultaneous bolus dose has not been given. For sole administration of nitrous oxide (70%) with remifentanil, typical maintenance infusion rates should be between 0.4 and 3 micrograms/kg/min, and although not specifically studied, adult data suggest that 0.4 micrograms/kg/min is an appropriate starting rate. Paediatric patients should be monitored and the dose titrated to the depth of analgesia appropriate for the surgical procedure.

Induction of anaesthesia: The use of remifentanil for induction of anaesthesia in patients aged 1 to 12 years is not recommended as there are no data available in this patient population.

Maintenance of anaesthesia: The following doses of Remifentanil are recommended for maintenance of anaesthesia:

DOSING GUIDELINES FOR PAEDIATRIC PATIENTS (1 to 12 years of age)

*CONCOMITANT ANAESTHETIC AGENT

BOLUS INJECTION

(micrograms/kg)

CONTINUOUS INFUSION

(micrograms/kg/min)

Starting Rate

Range

Halothane (starting dose 0.3MAC)

1

0.25

0.05 to 1.3

Sevoflurane (starting dose 0.3MAC)

1

0.25

0.05 to 0.9

Isoflurane (starting dose 0.5MAC)

1

0.25

0.06 to 0.9

*co-administered with nitrous oxide/oxygen in a ratio of 2:1

Concomitant medication: At the doses recommended above, remifentanil significantly reduces the amount of hypnotic agent required to maintain anaesthesia. Therefore, isoflurane, halothane and sevoflurane should be administered as recommended above to avoid an increase of haemodynamic effects such as hypotension and bradycardia. No data are available for dosage recommendations for simultaneous use of other hypnotics other than those listed in the table with remifentanil (see section 4.2.1.1 Adults- Concomitant medication).

Guidelines for patient management in the immediate post-operative period/ Establishment of alternative analgesia prior to discontinuation of remifentanil: Due to the very rapid offset of action of remifentanil, no residual activity will be present within 5 to 10 minutes after discontinuation. For those patients undergoing surgical procedures where post-operative pain is anticipated, analgesics should be administered prior to discontinuation of remifentanil. Sufficient time must be allowed to reach the therapeutic effect of the longer acting analgesic. The choice of agent(s), the dose and the time of administration should be planned in advance and individually tailored to be appropriate for the patient's surgical procedure and the level of post-operative care anticipated (see section 4.4).

4.2.1.3 Neonates/infants (aged less than 1 year):

There is limited clinical trial experience of remifentanil in neonates and infants (aged under 1 year old; see section 5.1). The pharmacokinetic profile of remifentanil in neonates/infants (aged less than 1 year) is comparable to that seen in adults after correction for body weight differences (see section 5.2). However, because there are insufficient clinical data, the administration of remifentanil is not recommended for this age group.

Use for Total Intravenous anaesthesia (TIVA): There is limited clinical trial experience of remifentanil of TIVA in infants (see section 5.1). However, there are insufficient clinical data to make dosage recommendations.

4.2.2 Cardiac anaesthesia

Administration by Manually-Controlled Infusion

DOSING GUIDELINES FOR CARDIAC ANAESTHESIA

INDICATION

BOLUS INJECTION

(micrograms/kg)

CONTINUOUS INFUSION

(micrograms/kg/min)

Starting Rate

Range

Induction of anaesthesia

Not recommended

1

_

Maintenance of anaesthesia in ventilated patients:

• Isoflurane

(starting dose 0.4MAC)

0.5 to 1

1

0.003 to 4

• Propofol

(Starting dose 50 micrograms/kg/min)

0.5 to 1

1

0.01 to 4.3

Continuation of post-operative analgesia, prior to extubation

Not recommended

1

0 to 1

Induction period of anaesthesia: After administration of hypnotic to achieve loss of consciousness, remifentanil should be administered at an initial infusion rate of 1 microgram/kg/min. The use of bolus injections of remifentanil during induction in cardiac surgical patients is not recommended. Endotracheal intubation should not occur until at least 5 minutes after the start of the infusion.

Maintenance period of anaesthesia: After endotracheal intubation the infusion rate of remifentanil can be titrated upward in 25% to 100% increments, or downward in 25% to 50% decrements, every 2 to 5 minutes according to patient need. Supplemental slow bolus doses, administered over not less than 30 seconds, may also be given every 2 to 5 minutes as required. High risk cardiac patients, such as those with poor ventricular function or undergoing valve surgery, should be administered a maximum bolus dose of 0.5 micrograms/kg. These dosing recommendations also apply during hypothermic cardiopulmonary bypass (see section 5.2).

Concomitant medication: At the doses recommended above, remifentanil significantly reduces the amount of hypnotic agent required to maintain anaesthesia. Therefore, isoflurane and propofol should be administered as recommended above to avoid excessive depth of anaesthesia. No data are available for dosage recommendations for simultaneous use of other hypnotics other than those listed in the table with remifentanil (see section 4.2.1.1 Adults - Concomitant medication).

Guidelines for post-operative patient management

Continuation of remifentanil post-operatively to provide analgesia prior to weaning for extubation: It is recommended that the infusion of remifentanil should be maintained at the final intra-operative rate during transfer of patients to the post-operative care area. Upon arrival into this area, the patient's level of analgesia and sedation should be closely monitored and the remifentanil infusion rate adjusted to meet the individual patient's requirements (see section 4.2.3 for further information on management of intensive care patients).

Establishment of alternative analgesia prior to discontinuation of remifentanil: Due to the very rapid offset of action of remifentanil, no residual opioid activity will be present within 5 to 10 minutes after discontinuation. Prior to discontinuation of remifentanil, patients must be given alternative analgesic and sedative agents at a sufficient time in advance to allow the therapeutic effects of these agents to become established. It is therefore recommended that the choice of agent(s), the dose and the time of administration are planned, before weaning the patient from the ventilator.

Guidelines for discontinuation of remifentanil: Due to the very rapid offset of action of remifentanil, hypertension, shivering and aches have been reported in cardiac patients immediately following discontinuation of remifentanil (see section 4.8). To minimise the risk of these occurring, adequate alternative analgesia must be established (as described above), before the remifentanil infusion is discontinued. The infusion rate should be reduced by 25% decrements in at least 10-minute intervals until the infusion is discontinued. During weaning from the ventilator the remifentanil infusion should not be increased and only down titration should occur, supplemented as required with alternative analgesics. Haemodynamic changes such as hypertension and tachycardia should be treated with alternative agents as appropriate.

When other opioid agents are administered as part of the regimen for transition to alternative analgesia, the patient must be carefully monitored. The benefit of providing adequate post-operative analgesia must always be balanced against the potential risk of respiratory depression with these agents.

Administration by Target-Controlled Infusion

Induction and maintenance of anaesthesia: remifentanil TCI should be used in association with an intravenous or inhalational hypnotic agent during the induction and maintenance of anaesthesia in ventilated adult patients (see table in Dosing Guidelines for Cardiac Anaesthesia under 4.2.2). In association with these agents, adequate analgesia for cardiac surgery is generally achieved at the higher end of the range of target blood remifentanil concentrations used for general surgical procedures. Following titration of remifentanil to individual patient response, blood concentrations as high as 20 nanograms/ml have been used in clinical studies. At the doses recommended above, remifentanil significantly reduces the amount of hypnotic agent required to maintain anaesthesia. Therefore, isoflurane and propofol should be administered as recommended above to avoid an increase of haemodynamic effects such as hypotension and bradycardia (see Table and Concomitant medication subsection in 4.2.2).

For information on blood remifentanil concentrations achieved with manually-controlled infusion see Table 6.

Guidelines for discontinuation/continuation into the immediate post-operative period: At the end of surgery when the TCI infusion is stopped or the target concentration reduced, spontaneous respiration is likely to return at calculated remifentanil concentrations in the region of 1 to 2 nanograms/ml. As with manually-controlled infusion, post-operative analgesia should be established before the end of surgery with longer acting analgesics (see Guidelines for discontinuation under Administration by manually-controlled infusion in section 4.2.2.)

As there are insufficient data, the administration of remifentanil by TCI for the management of post-operative analgesia is not recommended.

4.2.3 Use in Intensive Care

Remifentanil can be used for the provision of analgesia in mechanically ventilated intensive care patients. Sedative agents should be added as appropriate.

Remifentanil has been studied in mechanically ventilated intensive care patients in well controlled clinical trials for up to three days. As patients were not studied beyond three days, no evidence of safety and efficacy for longer treatment has been established. Therefore, the use of remifentanil is not recommended for a duration of treatment greater than 3 days.

Remifentanil TCI has not been studied in intensive care patients and therefore administration of remifentanil by TCI is not recommended in these patients.

In adults, it is recommended that remifentanil is initiated at an infusion rate of 0.1 micrograms/kg/min (6 micrograms/kg/h) to 0.15 micrograms/kg/min (9 micrograms/kg/h). The infusion rate should be titrated in increments of 0.025 micrograms/kg/min (1.5 micrograms/kg/h) to achieve the desired level of sedation and analgesia. A period of at least 5 minutes should be allowed between dose adjustments. The level of sedation and analgesia should be carefully monitored, regularly reassessed and the remifentanil infusion rate adjusted accordingly. If an infusion rate of 0.2 micrograms/kg/min (12 micrograms/kg/h) is reached and the desired level of sedation is not achieved, it is recommended that dosing with an appropriate sedative agent is initiated (see below). The dose of sedative agent should be titrated to obtain the desired level of sedation. Further increases to the remifentanil infusion rate in increments of 0.025 micrograms/kg/min (1.5 micrograms/kg/h) may be made if additional analgesia is required.

The following table summarises the starting infusion rates and typical dose range for provision of analgesia and sedation in individual patients:

DOSING GUIDELINES FOR USE OF REMIFENTANIL WITHIN THE INTENSIVE CARE SETTING

CONTINUOUS INFUSION micrograms/kg/min (micrograms/kg/h)

Starting Rate

Range

0.1 (6) to 0.15 (9)

0.006 (0.36) to 0.74 (44.4)

Bolus doses of remifentanil are not recommended in the intensive care setting.

The use of remifentanil will reduce the dosage requirement of any concomitant sedative agents. Typical starting doses for sedative agents, if required, are given below:

RECOMMENDED STARTING DOSE OF SEDATIVE AGENTS, IF REQUIRED

Sedative Agent

Bolus (mg/kg)

Infusion (mg/kg/h)

Propofol

Up to 0.5

0.5

Midazolam

Up to 0.03

0.03

To allow separate titration of the respective agents, sedative agents should not be prepared as one mixture in the same infusion bag.

Additional analgesia for ventilated patients undergoing stimulating procedures: An increase in the existing remifentanil infusion rate may be required to provide additional analgesic cover for ventilated patients undergoing stimulating and/or painful procedures such as endotracheal suctioning, wound dressing and physiotherapy. It is recommended that an remifentanil infusion rate of at least 0.1 micrograms/kg/min (6 micrograms/kg/h) should be maintained for at least 5 minutes prior to the start of the stimulating procedure. Further dose adjustments may be made every 2 to 5 minutes in increments of 25%-50% in anticipation of, or in response to, additional requirement for analgesia. A mean infusion rate of 0.25 micrograms/kg/min (15 micrograms/kg/h), maximum 0.75 micrograms/kg/min (45 micrograms/kg/h), has been administered for provision of additional analgesia during stimulating procedures.

Establishment of alternative analgesia prior to discontinuation of remifentanil: Due to the very rapid offset of action of remifentanil, no residual opioid activity will be present within 5 to 10 minutes after discontinuation regardless of the duration of infusion. Following administration of remifentanil, the possibility of tolerance, hyperalgesia and associated haemodynamic changes should be considered when used in Intensive Care Unit (see Section 4.4 Special warnings and precautions for use. Therefore, prior to discontinuation of remifentanil, patients must be given alternative analgesic and sedative agents to prevent hyperalgesia and associated haemodynamic changes. These agents must be given at a sufficient time in advance to allow the therapeutic effects of these agents to become established. The range of options for analgesia includes long acting oral, intravenous, or regional analgesics controlled by the nurse or the patient. These techniques should always be titrated to individual patient needs as the infusion of remifentanil is reduced. It is recommended that the choice of agent(s), the dose, and the time of administration are planned prior to discontinuation of remifentanil.

There is a potential for the development of tolerance with time during prolonged administration of mu-opioid agonists.

Guidelines for extubation and discontinuation of remifentanil: In order to ensure a smooth emergence from an remifentanil-based regimen it is recommended that the infusion rate of remifentanil is titrated in stages to 0.1 micrograms/kg/min (6 micrograms/kg/h) over a period up to 1 hour prior to extubation.

Following extubation, the infusion rate should be reduced by 25% decrements in at least 10-minute intervals until the infusion is discontinued. During weaning from the ventilator the remifentanil infusion should not be increased and only down titration should occur, supplemented as required with alternative analgesics.

Upon discontinuation of remifentanil, the IV cannula should be cleared or removed to prevent subsequent inadvertent administration.

When other opioid agents are administered as part of the regimen for transition to alternative analgesia, the patient must be carefully monitored. The benefit of providing adequate analgesia must always be balanced against the potential risk of respiratory depression.

4.2.3.1 Paediatric intensive care patients

The use of remifentanil in intensive care patients under the age of 18 years is not recommended as there are no data available in this patient population.

4.2.3.2 Renally-impaired intensive care patients

No adjustments to the doses recommended above are necessary in renally-impaired patients, including those undergoing renal replacement therapy; however the clearance of the carboxylic acid metabolite is reduced in patients with renal impairment (see section 5.2).

4.2.4 Special patient populations

4.2.4.1 Elderly (over 65 years of age)

General anaesthesia: The initial starting dose of remifentanil administered to patients over 65 should be half the recommended adult dose and then shall be titrated to individual patient need as an increased sensitivity to the pharmacological effects of remifentanil has been seen in this patient population. This dose adjustment applies to use in all phases of anaesthesia including induction, maintenance, and immediate post-operative analgesia.

Because of the increased sensitivity of elderly patients to remifentanil, when administering Remifentanil by TCI in this population the initial target concentration should be 1.5 to 4 nanograms/ml with subsequent titration to response.

Cardiac anaesthesia: No initial dose reduction is required (see section 4.2.2.).

Intensive Care: No initial dose reduction is required (see section 4.2.3.).

4.2.4.2 Obese patients

For manually-controlled infusion it is recommended that for obese patients the dosage of remifentanil should be reduced and based upon ideal body weight as the clearance and volume of distribution of remifentanil are better correlated with ideal body weight than actual body weight.

With the calculation of lean body mass (LBM) used in the Minto model, LBM is likely to be underestimated in female patients with a body mass index (BMI) greater than 35 kg/m2 and in male patients with BMI greater than 40 kg/m2. To avoid underdosing in these patients, remifentanil TCI should be titrated carefully to individual response.

4.2.4.3 Renal impairment

On the basis of investigations carried out to date, a dose adjustment in patients with impaired renal function, including intensive care patients, is not necessary.

4.2.4.4 Hepatic impairment

Studies carried out with a limited number of patients with impaired liver function, do not justify any special dosage recommendations. However, patients with severe hepatic impairment may be slightly more sensitive to the respiratory depressant effects of remifentanil (see section 4.4). These patients shall be closely monitored and the dose of remifentanil shall be titrated to individual patient need.

4.2.4.5 Neurosurgery

Limited clinical experience in patients undergoing neurosurgery has shown that no special dosage recommendations are required.

4.2.4.6 ASA III/IV patients

General anaesthesia: As the haemodynamic effects of potent opioids can be expected to be more pronounced in ASA III/IV patients, caution should be exercised in the administration of remifentanil in this population. Initial dosage reduction and subsequent titration to effect is therefore recommended. In paediatric patients, there are insufficient data to make a dosage recommendation.

For TCI, a lower initial target of 1.5 to 4 nanograms/ml should be used in ASA III or IV patients and subsequently titrated to response.

Cardiac anaesthesia: No initial dose reduction is required (see section 4.2.2).

4.3. Contraindications

As glycine is present in the formulation, Remifentanil is contraindicated for epidural and intrathecal use.

Hypersensitivity to the active substance, other fentanyl analogues, or to any of the excipients listed in section 6.1.

Remifentanil is contraindicated for use as the sole agent for induction of anaesthesia.

4.4. Special warnings and precautions for use

Remifentanil should be administered only in a setting fully equipped for the monitoring and support of respiratory and cardiovascular function, and by persons specifically trained in the use of anaesthetic drugs and the recognition and management of the expected adverse effects of potent opioids, including respiratory and cardiac resuscitation. Such training must include the establishment and maintenance of a patent airway and assisted ventilation. The use of remifentanil in mechanically ventilated intensive care patients is not recommended for a duration of treatment greater than 3 days.

Patients with a known hypersensitivity to opioids of a different class may exhibit a hypersensitivity reaction following administration of remifentanil. Caution should be exercised before using remifentanil in these patients.

Rapid offset of action /Transition to alternative analgesia

Due to the very rapid offset of action of remifentanil, no residual opioid activity will be present within 5 to 10 minutes after the discontinuation of remifentanil. For those patients undergoing surgical procedures where post-operative pain is anticipated, analgesics should be administered prior to discontinuation of remifentanil. The possibility of tolerance, hyperalgesia and associated haemodynamic changes should be considered when used in Intensive Care Unit (see Section 4.2 Posology and method of administration). Prior to discontinuation of remifentanil, patients must be given alternative analgesic and sedative agents. Sufficient time must be allowed to reach the therapeutic effect of the longer acting analgesic. The choice of agent(s), the dose and the time of administration should be planned in advance and individually tailored to be appropriate for the patient's surgical procedure and the level of post-operative care anticipated. When other opioid agents are administered as part of the regimen for transition to alternative analgesia, the benefit of providing adequate post-operative analgesia must always be balanced against the potential risk of respiratory depression with these agents.

Risk from concomitant use of sedative medicines such as benzodiazepines or related drugs.

Concomitant use of remifentanil and sedative medicines such as benzodiazepines or related drugs may result in sedation, respiratory depression, coma and death. Because of these risks, concomitant prescribing with these sedative medicines should be reserved for patients for whom alternative treatment options are not possible. If a decision is made to prescribe remifentanil concomitantly with sedative medicines, the lowest effective dose should be used, and the duration of treatment should be as short as possible.

The patients should be followed closely for signs and symptoms of respiratory depression and sedation. In this respect, it is strongly recommended to inform patients and their caregivers to be aware of these symptoms (see section 4.5).

Discontinuation of Treatment and withdrawal syndrome

Repeated administration at short term intervals for prolonged periods may result in the development of withdrawal syndrome after cessation of therapy. Symptoms following withdrawal of remifentanil including tachycardia, hypertension and agitation have been reported infrequently upon abrupt cessation, particularly after prolonged administration of more than 3 days. Where reported, re-introduction and tapering of the infusion has been beneficial. The use of remifentanil in mechanically ventilated intensive care patients is not recommended for duration of treatment greater than 3 days.

Inadvertent administration

A sufficient amount of remifentanil may be present in the dead space of the IV line and/or cannula to cause respiratory depression, apnoea and/or muscle rigidity if the line is flushed with IV fluids or other drugs. This may be avoided by administering remifentanil into a fast flowing IV line or via a dedicated IV line which is removed when remifentanil is discontinued.

Muscle rigidity - prevention and management

At the doses recommended muscle rigidity may occur. As with other opioids, the incidence of muscle rigidity is related to the dose and rate of administration. Therefore, bolus injections should be administered over not less than 30 seconds.

Muscle rigidity induced by remifentanil must be treated in the context of the patient's clinical condition with appropriate supporting measures including ventilatory support. Excessive muscle rigidity occurring during the induction of anaesthesia should be treated by the administration of a neuromuscular blocking agent and/or additional hypnotic agents. Muscle rigidity seen during the use of remifentanil as an analgesic may be treated by stopping or decreasing the rate of administration of remifentanil. Resolution of muscle rigidity after discontinuing the infusion of remifentanil occurs within minutes. Alternatively an opioid antagonist may be administered, however this may reverse or attenuate the analgesic effect of remifentanil.

Respiratory depression – prevention and management

As with all potent opioids, profound analgesia is accompanied by marked respiratory depression. Therefore, remifentanil should only be used in areas where facilities for monitoring and dealing with respiratory depression are available. The appearance of respiratory depression should be managed appropriately, including decreasing the rate of infusion by 50%, or by a temporary discontinuation of the infusion. Unlike other fentanyl analogues, remifentanil has not been shown to cause recurrent respiratory depression even after prolonged administration. However, as many factors may affect post-operative recovery it is important to ensure that full consciousness and adequate spontaneous ventilation are achieved before the patient is discharged from the recovery area.

Cardiovascular effects

The risk of cardiovascular effects such as hypotension and bradycardia (see section 4.8), which may rarely lead to asystole/cardiac arrest may be reduced by lowering the rate of infusion of remifentanil or the dose of concurrent anaesthetics or by using IV fluids, vasopressor or anticholinergic agents as appropriate.

Debilitated, hypovolaemic, and elderly patients may be more sensitive to the cardiovascular effects of remifentanil.

Neonates/infants

There is limited data available on use in neonates/infants under 1 year of age (see sections 4.2.1.3 and 5.1).

Tolerance and opioid use disorder (abuse and dependence)

Tolerance, physical and psychological dependence, and opioid use disorder (OUD) may develop upon repeated administration of opioids. Abuse or intentional misuse of opioids may result in overdose and/or death. The risk of developing OUD is increased in patients with a personal or a family history (parents or siblings) of substance use disorders (including alcohol use disorder), in current tobacco users or in patients with a personal history of other mental health disorders (e.g. major depression, anxiety and personality disorders).

This medicine contains sodium

This medicine contains less than 1 mmol sodium (23 mg) per vial, that is to say essentially 'sodium-free'.

4.5. Interaction with other medicinal products and other forms of interaction

Remifentanil is not metabolised by plasmacholinesterase, therefore, interactions with drugs metabolised by this enzyme are not anticipated.

As with other opioids, remifentanil, whether given by manually-controlled infusion or TCI, decreases the amounts or doses of inhaled and IV anaesthetics, and benzodiazepines required for anaesthesia (see section 4.2 Posology and method of administration, General Anaesthesia – Adults, Paediatric Patients, and Cardiac Surgery). If doses of concomitantly administered CNS depressant drugs are not reduced, patients may experience an increased incidence of adverse effects associated with these agents.

Sedative medicines such as benzodiazepines or related drugs

The concomitant use of opioids with sedative medicines such as benzodiazepines or related drugs increases the risk of sedation, respiratory depression, coma and death because of additive CNS depressant effect. The dose and duration of concomitant use should be limited (see section 4.4). The concomitant use of opioids and gabapentinoids (gabapentin and pregabalin) increases the risk of opioid overdose, respiratory depression and death.

Co-administration of remifentanil with a serotonergic agent, such as Selective Serotonin Reuptake Inhibitors (SSRIs), Serotonin Norepinephrine Reuptake Inhibitors (SNRIs) or Monoamine Oxidase Inhibitors (MAOIs) may increase the risk of serotonin syndrome, a potentially life-threatening condition. Caution should be exercised with concomitant use of MAOIs. Irreversible MAOIs should be discontinued at least 2 weeks prior to remifentanil use.

The cardiovascular effects of remifentanil (hypotension and bradycardia), may be exacerbated in patients receiving concomitant cardiac depressant drugs, such as beta-blockers and calcium channel blocking agents.

After receiving remifentanil, it is advisable that alcoholic drink is avoided.

4.6. Fertility, pregnancy and lactation

Pregnancy

There are no adequate and well-controlled studies in pregnant women. Remifentanil should be used during pregnancy only if the potential benefit justifies the potential risk to the foetus.

Breast-feeding

It is not known whether remifentanil is excreted in human milk. However, because fentanyl analogues are excreted in human milk and remifentanil-related material was found in rat milk after dosing with remifentanil, nursing mothers should be advised to discontinue breast feeding for 24 hours following administration of remifentanil.

For a summary of the reproductive toxicity study findings please refer to Section 5.3 Preclinical safety data.

Labour and delivery

The safety profile of remifentanil during labour or delivery has not been demonstrated. There are insufficient data to recommend remifentanil for use during labour and Caesarean section. Remifentanil crosses the placental barrier and fentanyl analogues can cause respiratory depression in the child. In case remifentanil is administered nevertheless, the patient and the neonate must be monitored for signs of excess sedation or respiratory depression (see section 4.4).

4.7. Effects on ability to drive and use machines

After anaesthesia with remifentanil the patient should not drive or operate machinery. The physician should decide when these activities may be resumed. It is advisable that the patient is accompanied when returning home.

This medicine can impair cognitive function and can affect a patient's ability to drive safely. This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988. When prescribing this medicine, patients should be told:

• The medicine is likely to affect your ability to drive

• Do not drive until you know how the medicine affects you

• It is an offence to drive while under the influence of this medicine

• However, you would not be committing an offence (called 'statutory defence') if:

o The medicine has been prescribed to treat a medical or dental problem and

o You have taken it according to the instructions given by the prescriber and in the information provided with the medicine and

o It was not affecting your ability to drive safely

4.8. Undesirable effects

Summary of the safety profile

The most common undesirable effects associated with remifentanil are direct extensions of mu-opioid agonist pharmacology. These adverse events resolve within minutes of discontinuing or decreasing the rate of remifentanil administration.

Tabulated list of adverse reactions

The frequencies below are defined as very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000) and very rare (<1/10,000), not known (cannot be estimated from the available data).

System Organ Class

Frequency

Adverse reactions

Immune System Disorders

Rare

Allergic reactions including anaphylaxis have been reported in patients receiving remifentanil in conjunction with one or more anaesthetic agents

Not known

Anaphylactic shock

Psychiatric disorders

Not known

Drug dependence, withdrawal syndrome

Nervous System Disorders

Very common

Skeletal muscle rigidity

Rare

Sedation (during recovery from general anaesthesia)

Not known

Convulsions

Cardiac Disorders

Common

Bradycardia

Rare

Asystole/cardiac arrest, usually preceded by bradycardia, has been reported in patients receiving remifentanil in conjunction with other anaesthetic agents

Not known

Atrioventricular block, arrhythmia

Vascular Disorders

Very common

Hypotension

Common

Post-operative hypertension

Respiratory, Thoracic and Mediastinal Disorders

Common

Acute respiratory depression, apnoea, cough

Uncommon

Hypoxia

Gastrointestinal Disorders

Very common

Nausea, vomiting

Uncommon

Constipation

Skin and Subcutaneous Tissue Disorders

Common

Pruritus

General Disorders and Administration Site Conditions

Common

Post-operative shivering

Uncommon

Post-operative aches

Not known

Drug tolerance

Discontinuation of treatment

Symptoms following withdrawal of remifentanil including tachycardia, hypertension and agitation have been reported infrequently upon abrupt cessation, particularly after prolonged administration of more than 3 days (see section 4.4).

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme:

Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

Symptoms

As with all potent opioid analgesics, overdose would be manifested by an extension of the pharmacologically predictable actions of remifentanil. Due to the very short duration of action of remifentanil, the potential for deleterious effects due to overdose is limited to the immediate time period following drug administration. Response to discontinuation of the drug is rapid, with return to baseline within ten minutes.

Management

In the event of overdose, or suspected overdose, take the following actions: discontinue administration of remifentanil, maintain a patent airway, initiate assisted or controlled ventilation with oxygen, and maintain adequate cardiovascular function. If depressed respiration is associated with muscle rigidity, a neuromuscular blocking agent may be required to facilitate assisted or controlled respiration. Intravenous fluids and vasopressor agents for the treatment of hypotension and other supportive measures may be employed.

Intravenous administration of an opioid antagonist such as naloxone may be given as a specific antidote in addition to ventilatory support to manage severe respiratory depression. The duration of respiratory depression following overdose with remifentanil is unlikely to exceed the duration of action of the opioid antagonist.