Revised: January 2011
AN: 01242/2010
SUMMARY OF THE PRODUCT CHARACTERISTICS
- NAME OF THE VETERINARY MEDICINAL PRODUCT
Isoflurane Virbac 100% w/w Inhalation Vapour, Liquid
2.QUALITATIVE AND QUANTITATIVE COMPOSITION
Active substance
Isoflurane 100 % w/w
3.PHARMACEUTICAL FORM
Inhalation vapour, liquid.
4.CLINICAL PARTICULARS
4.1Target species
Dogs and cats.
4.2Indications for use, specifying the target species
Induction and maintenance of general anaesthesia.
4.3Contra-indications
A known sensitivity to isoflurane. A known susceptibility to malignant hyperthermia.
4.4Special warnings for each target species
None.
4.5Special precautions for use
i.Special precautions for use in animals
The lowest effective dose should be administered.
ii.Special precautions to be taken by the person administering the medicinal products to animals
Do not breathe vapour. The Occupation Exposure Standard (OES) for isoflurane has been set at 50 ppm on an 8-hour time weighed average.
Operating rooms and recovery areas should be provided with adequate ventilation or scavenging systems to prevent the accumulation of anaesthetic vapour.
All scavenging/extraction systems must be adequately maintained.
To protect the environment, it is considered good practice to use charcoal filters with scavenging/ventilation equipment.
Avoid using masking procedures for prolonged induction and maintenance of general anaesthesia.
Used cuffed endotracheal intubation when possible for the administration of isoflurane during maintenance of general anaesthesia.
Care should be taken when dispensing isoflurane, with any spillage removed immediately using an inert and absorbent material e.g. sawdust.
Pregnant and breast-feeding women should avoid exposure to the product and should avoid operating rooms and animal recovery areas.
Wash any splashes from skin and eyes immediately and avoid contact with the mouth.
In the event of severe accidental exposure, remove the operator from the source of exposure and seek urgent medical assistance and show this label.
Halogenated anaesthetic agents may induce liver damage. In the case of isoflurane this is an idiosyncratic response very-rarely seen after repeated exposure.
Advice to doctors: ensure a patent airway and give symptomatic and supportive treatment. Note that adrenaline and catecholamines may cause cardiac dysrhythmias.
4.6Adverse reactions (frequency and seriousness)
Dose-dependent cardiovascular depression.
Dose-dependent respiratory depression.
Malignant hyperthermia (rare).
Increased cerebral-blood flow and intracranial pressure (of importance in cranial surgery and patients with head injuries).
4.7Use during pregnancy, lactation or lay
Isoflurane has been safely used for caesarean section in the dog and cat. Fully comprehensive data on isoflurane use during pregnancy and lactation in the target species have not been obtained.
4.8Interaction with other medicinal products and other forms of interaction
Delivery in nitrous oxide and premedication with agents such as acepromazine, opioids, benzodiazepines and alpha-2-adrenoreceptor agonists are compatible with isoflurane use; however concurrent use of such agents is expected to reduce the concentration of isoflurane necessary for induction and maintenance.
Isoflurane enhances the potency of non-depolarising muscle relaxants, in particular with respect to their duration of action.
Isoflurane may be degraded to carbon monoxide by dried carbon dioxide absorbents.
4.9Amounts to be administered and administration route
Minimum Alveolar Concentration: the M.A.C. value of isoflurane is 1.28 % in the dog and 1.63 % in the cat.
Induction of anaesthesia: anaesthesia of dogs and cats may be induced by inspired isoflurane concentrations of between 2 and 4 %. Premedication and/or concurrent use of nitrous oxide reduces the concentration of isoflurane required. If anaesthesia is induced with an injectable agent, an initial isoflurane concentration slightly above that required for maintenance should usually be administered to aid the transition onto gaseous anaesthesia.
Maintenance of anaesthesia: as a general rule, concentrations of around 1.5 M.A.C. are necessary for anaesthetic maintenance. In practice, levels of 1.5 - 2.5 % in the dog and 1.5 - 3.0 % in the cat are used. Again, premedication and/or concurrent use of nitrous oxide reduces the concentration of isoflurane.
Isoflurane should be administered using an accurately calibrated vaporiser in association with an appropriate anaesthetic circuit.
4.10Overdose (symptoms, emergency procedures, antidotes), if necessary
Skilled monitoring of anaesthetic depth should accompany isoflurane use. As the primary signs of overdose are due to cardiopulmonary depression, cardiovascular signs (e.g. pulse strength, heart rate, mucous-membrane colour and refill) and respiratory signs (rate and depth of respiration) should be particularly noted.
If cardiopulmonary parameters are overly depressed by the agent, reducing the inspired concentration will normally be sufficient to correct this.
In the event of severe overdosage, cease isoflurane administration. An endotracheal tube should be passed if one is not already in place and positive pressure ventilation with oxygen commenced.
4.11Withdrawal period
Not applicable.
5.PHARMACOLOGICAL PROPERTIES
ATCvet code: QN01AB06.
Pharmacotherapeutic group: halogenated hydrocarbons.
5.1Pharmacodynamic properties
Summary of the major pharmacological characteristics of isoflurane as an inhalation anaesthetic:
general CNS depressant, causing a dose-related depression of the level of consciousness to the state of surgical anaesthesia.
Volatile, allowing rapid changes in the depth of anaesthesia by a suitably skilled anaesthetist.
Relatively-rapid induction of anaesthesia.
Smooth recovery.
Dose-dependent depression of cardiopulmonary function.
Lack of arrhythmmogenic properties upon the myocardium.
Minimal metabolism by the body (less than 0.2 %) and so-high index of hepatic and renal safety.
Stability of storage, being non-flammable, non-explosive and stable in the presence of soda lime and U.V. light.
6.PHARMACEUTICAL PARTICULARS
6.1List of excipients
None.
6.2Incompatibilities
Carbon-monoxide production from contact with dessicated soda- or baro- lime has been reported. This is avoided by ensuring that soda-lime is fresh or rehydrated if it has become dessicated.
6.3Shelf life
Shelf life of the veterinary medicinal product as packaged for sale: 2 years.
6.4.Special precautions for storage
Do not store above 25 °C. Store in tightly-closed original container.
Protect from direct sunlight.
6.5Nature and composition of immediate packaging
250 ml in a glass bottle with tamper evident polyethylene lined caps.
6.6Special precautions for the disposal of unused veterinary medicinal product or waste materials derived from the use of such products, if appropriate
Any unused veterinary medicinal product or waste materials derived from such veterinary medicinal products should be disposed of in accordance with local requirements.
7.MARKETING-AUTHORISATION HOLDER
Virbac Ltd
Woolpit Business Park
Windmill Avenue
Woolpit
Bury St Edmunds
Suffolk
IP30 9UP
United Kingdom
8.MARKETING-AUTHORISATION NUMBER
Vm 11188/4009
9.DATE OF LAST RENEWAL OF THE AUTHORISATION
02 March 2006.
10.DATE OF REVISION OF THE TEXT
January 2011
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