Posology : מינונים

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 m u s t be administered by a calibrated infusion device into a fast- flowing I.V line or via a dedicated I.V line. This infusion line should be connected at, or close to the venous Cannula and primed to minimize the potential dead space (see section 6.6.)

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 (I.V.) 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 6.3 and 6.6 for storage conditions of the reconstituted/diluted product and the recommended diluents).
Administration by Manually-Controlled Infusion
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).
(See sectionn 6.6)
          4.2.1 General Anaesthesia

The administration of Remifentanil must be individualized 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                      Continuous Infusion (micrograms/kg)                         (micrograms/kg/ min)
Starting rate         Range
Induction of anaesthesia                            1
(give over not less than 30         0.5 to 1                    - seconds)
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 dose100                  0.5 to 1                          0.25               0.05 to 2 micrograms/kg/min)

When given by bolus infusion at induction Remifentanil s h o u l d 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 treatment).

Induction of anaesthesia: Remifentanil should be adminstered with a standard dose of a hypnotic agent, such as propofol, thiopental, thiopentone or isoflurane, for the induction of anaesthesia.
Administering Remifentanil after a 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 infusion 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 injection 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.
In ventilated patients, the infusion rate should continue to be titrated to 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.


4.2.1.2 Paediatric patients (2 to 12 years of age)
Induction of anaesthesia: There are insufficient data to make a dosage recommendation.

4.2.2 Cardiac anaesthesia

Administration by Manually-Controlled Infusion

DOSING GUIDELINES FOR CARDIAC ANAESTHESIA

INDICATION                      BOLUS INJECTION            CONTINUOUS INFUSION OF REMIFENTANIL            OF REMIFENTANIL
(micrograms/kg)            (micrograms/kg/min)


Starting Rate     Typical
Infusion
Rates
Intubation                      Not recommended            1                 _ Maintenance of anaesthesia in ventilated patients:
Isoflurane (starting      0.5 to 1                   1                 0.003 to 4 dose 0.4MAC)
Propofol (starting        0.5 to 1                   1                 0.01 to 4.3 dose 50
(micrograms/kg/min
)
Continuation of post-           Not recommended            1                 0 to 1 operative analgesia, prior to extubation


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 injection of Remifentanil during induction in cardiac surgical patients is not recommended. Endotracheal intubation should not occur until at least 5 min 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 with Remifentanil (see section 4.2.1.1 Posology and Method of Administration, 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 furter 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 minutes 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.


Paediatric patients
There are insufficient data to make a dosage recommendation for use during cardiac surgery.

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 of Remifentanil is not recommended for a duration of treatment greater than 3 days.
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 analgesia and sedation. A period of at least 5 minutes should be allowed between dose adjustments. The level of analgesia and sedation 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. 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 agent's 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 a Remifentanil infusion rate of at least 0.1 micrograms/kg/min (6 micrograms/kg/h) should be maintained for at least 5 min prior to the start of the stimulating procedure. Further dose adjustments may be made every 2 to 5 minutes in increments of 25% to 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 and hyperalgesia should be considered. 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 a 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 minutes 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 intravenous (I.V)_ cannula should be cleared or removed to prevent subsequent inadvertent administration of the drug.


When other opioids 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 Pediatric 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.

Cardiac anaesthesia: No initial dose reduction is required (see section 4.2.2 Posology, Cardiac Anaesthesia — Dosing guidelines).


Intensive Care: No initial dose reduction is required (see section 4.2.3 Posology and Method of Administration, Use in Intensive Care).

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 in this population.

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 should 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 neorosurgery has shown that no special dosage recommendations are required.

4.2.4.6 Patients in ASA groups III/IV

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.

Cardiac anaesthesia: No initial dose reduction is required (see section 4.2.2 Posology and Method of Administration, Cardiac Anesthesia dosing guideline section).