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POM-V Prescription Required Companion Animal

Sevotek 1000 mg/g Inhalation Vapour, Liquid for Dogs and Cats

Active ingredient: Sevoflurane

Form

Inhalation vapour, liquid

Species

Cats Dogs

Manufacturer

Laboratorios Karizoo S.A

VMD MA No.

31223/4007

What it's used for

For the induction and maintenance of anaesthesia.

Full indications, dosage and side effects ↓
View official SPC (PDF)

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Paying less for Sevoflurane

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    The CMA found online pharmacies 50–60% cheaper than practice dispensing on common medicines — typically £200–£300 a year.

Prescription required

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Clinical information

Sevotek 1000 mg/g Inhalation Vapour, Liquid for Dogs and Cats — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 26 Mar 2026.

For the induction and maintenance of anaesthesia.
Inhalation use.
Inspired Concentration:
The veterinary medicinal product should be administered via a vaporiser specifically
calibrated for use with sevoflurane so that the concentration delivered can be
accurately controlled. The veterinary medicinal product contains no stabiliser and
does not affect the calibration or operation of these vaporisers in any way. The
administration of sevoflurane must be individualised based on the dog's or cat’s
response.

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Premedication:
The necessity for and choice of premedication is left to the discretion of the
veterinarian. Preanaesthetic doses for premedicants may be lower than the label
directions for their use as a single medication.
Induction of anaesthesia:
For mask induction using sevoflurane, inspired concentrations of 5 to 7% sevoflurane
with oxygen are employed to induce surgical anaesthesia in the healthy dog, and 6 to
8% sevoflurane with oxygen in the cat. These concentrations can be expected to
produce surgical anaesthesia within 3 to 14 minutes in dogs and within 2 to 3
minutes in cats. Sevoflurane concentration for induction may be set initially, or may
be achieved gradually over the course of 1 to 2 minutes. The use of premedicants
does not affect the concentration of sevoflurane required for induction.
Maintenance of anaesthesia:
Sevoflurane may be used for maintenance anaesthesia following mask induction with
sevoflurane or following induction with injectable agents. The concentration of
sevoflurane necessary to maintain anaesthesia is less than that required for
induction.
Surgical levels of anaesthesia in the healthy dog may be maintained with inhaled
concentrations of 3.3 to 3.6% in the presence of premedication. In the absence of
premedication, inhaled concentrations of sevoflurane in the range 3.7 to 3.8% will
provide surgical levels of anaesthesia in the healthy dog. In the cat surgical
anaesthesia is maintained with sevoflurane concentrations of 3.7-4.5%. The
presence of surgical stimulation may require an increase in the concentration of
sevoflurane. The use of injectable induction agents without premedication has little
effect on the concentrations of sevoflurane required for maintenance. Anaesthetic
regimens that include opioid, alpha-2-agonist, benzodiazepine or phenothiazine
premedication will allow the use of lower sevoflurane maintenance concentrations.
Do not use in animals with known hypersensitivity to sevoflurane or other
halogenated anaesthetic agents.
Do not use in animals with a known or suspected genetic susceptibility to malignant
hyperthermia.
Hypotension, tachypnoea, muscle tenseness, excitation, apnoea, muscle
fasciculations and emesis have been reported as very common adverse reactions,
based on post-authorisation spontaneous reporting experience.
Dose-dependent respiratory depression is commonly observed while using
sevoflurane, therefore respiration should be closely monitored during sevoflurane
anaesthesia and the inspired concentration of sevoflurane adjusted accordingly.
Anaesthetic-induced bradycardia is commonly observed during sevoflurane
anaesthesia. It may be reversed by administration of anticholinergics.
Paddling, retching, salivation, cyanosis, premature ventricular contractions and
excessive cardiopulmonary depression have been reported very rarely based on
post-authorisation spontaneous reporting experience.
In dogs, transient elevations in aspartate aminotransferase (AST), alanine
aminotransferase (ALT), lactate dehydrogenase (LDH), bilirubin and white blood cell
counts may occur with sevoflurane, as with the use of other halogenated anaesthetic
agents. In cats, transient increases in AST and ALT may occur with sevoflurane,
however, hepatic enzymes tend to remain within the normal range.
Hypotension during sevoflurane anaesthesia may result in decreased renal blood
flow.
The possibility of sevoflurane triggering episodes of malignant hyperthermia in
susceptible dogs and cats cannot be ruled out.
The frequency of adverse reactions is defined using the following convention:
- very common (more than 1 in 10 animals treated displaying adverse reaction(s))
- common (more than 1 but less than 10 animals in 100 animals treated)
- uncommon (more than 1 but less than 10 animals in 1,000 animals treated)
- rare (more than 1 but less than 10 animals in 10,000 animals treated)
- very rare (less than 1 animal in 10,000 animals treated, including isolated reports).
None.

Special precautions for use in animals
Halogenated volatile anaesthetics can react with dry carbon dioxide (CO2)
absorbents to produce carbon monoxide (CO) that may result in elevated levels of
carboxyhaemoglobin in some dogs. In order to minimise this reaction in rebreathing
anaesthetic circuits, the veterinary medicinal product should not be passed through
soda lime or barium hydroxide that has been allowed to dry out.

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The exothermic reaction that occurs between inhalation agents (including
sevoflurane) and CO2 absorbents is increased when the CO2 absorbent becomes
desiccated, such as after an extended period of dry gas flow through the CO2
absorbent canisters. Rare cases of excessive heat production, smoke and/or fire in
the anaesthetic machine have been reported during the use of a desiccated CO2
absorbent and sevoflurane. An unusual decrease in the expected depth of
anaesthesia compared to the vaporiser setting may indicate excessive heating of the
CO2 absorbent canister.
If it is suspected that the CO2 absorbent may be desiccated, it must be replaced. The
colour indicator of most CO2 absorbents does not necessarily change as a result of
desiccation. Therefore, the lack of significant colour change should not be taken as
an assurance of adequate hydration. CO2 absorbents should be replaced routinely
regardless of the state of the colour indicator.
1,1,3,3,3-pentafluoro-2-(fluoromethoxy)propene (C4H2F6O), also known as
Compound A, is produced when sevoflurane interacts with soda lime or barium
hydroxide. Reaction with barium hydroxide results in a greater production of
Compound A than does the reaction with soda lime. Its concentration in a circle
absorber system increases with increasing sevoflurane concentrations and with
decreasing fresh gas flow rates. Sevoflurane degradation in soda lime has been
shown to increase with temperature. Since the reaction of carbon dioxide with
absorbents is exothermic, this temperature increase will be determined by the
quantities of CO2 absorbed, which in turn will depend on fresh gas flow in the
anaesthetic circle system, metabolic status of the dog and ventilation. Although
Compound A is a dose-dependent nephrotoxin in rats, the mechanism of this renal
toxicity is unknown. Long-duration, low-flow sevoflurane anaesthesia should be
avoided due to the risks of Compound A accumulation.
During maintenance of anaesthesia, increasing the concentration of sevoflurane
produces a dose-dependent decrease in blood pressure. Due to sevoflurane's low
solubility in blood, these haemodynamic changes may occur more rapidly than with
other volatile anaesthetics. Arterial blood pressure should be monitored at frequent
intervals during sevoflurane anaesthesia. Facilities for artificial ventilation, oxygen
enrichment and circulatory resuscitation should be immediately available. Excessive
decreases in blood pressure or respiratory depression may be related to the depth of
anaesthesia and may be corrected by decreasing the inspired concentration of
sevoflurane. The low solubility of sevoflurane also facilitates rapid elimination by the
lungs. The nephrotoxic potential of certain NSAIDs, when used in the perioperative
period, may be exacerbated by hypotensive episodes during sevoflurane
anaesthesia. In order to maintain renal blood flow, prolonged episodes of
hypotension (mean arterial pressure below 60 mmHg) should be avoided in dogs and
cats during sevoflurane anaesthesia.
In common with all volatile agents, sevoflurane may cause hypotension in
hypovolaemic animals such as those requiring surgery to repair traumatic injury, and
lower doses should be administered in combination with appropriate analgesics.
Sevoflurane may trigger episodes of malignant hyperthermia in susceptible dogs and
cats. If malignant hyperthermia develops, the anaesthetic supply should be

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interrupted immediately and 100% oxygen administered using fresh anaesthetic
hoses and a rebreathing bag. Appropriate treatment should readily be instituted.
Compromised or debilitated dogs and cats
Doses of sevoflurane may need adjustment for geriatric or debilitated animals. Doses
required for maintenance anaesthesia may need to be reduced by approximately
0.5% in geriatric dogs (i.e. 2.8% to 3.1% in premedicated geriatric dogs and 3.2 to
3.3% in unpremedicated geriatric dogs). There is no information on the adjustment of
the maintenance dose in cats. Adjustment is, therefore, left to the discretion of the
veterinarian. Limited clinical experience in administering sevoflurane to animals with
renal, hepatic and cardiovascular insufficiency suggests that sevoflurane may be
safely used in these conditions. However, it is recommended that such animals be
monitored carefully during sevoflurane anaesthesia.
Sevoflurane may cause a small increase in intracranial pressure (ICP) under
conditions of normocapnia in dogs. In dogs with head injuries or other conditions
placing them at risk from increased ICP, it is recommended that hypocapnia be
induced by means of controlled hyperventilation as a means of preventing changes in
ICP.
There are limited data to support the safety of sevoflurane in animals less than 12
weeks of age. Therefore, it should only be used in these animals according to a
benefit-risk assessment by the responsible veterinary surgeon.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
In order to minimise exposure to sevoflurane vapour, the following recommendations
are made:
•
sevoflurane during maintenance anaesthesia.
•
general anaesthesia.
•
adequate ventilation or scavenging systems to prevent the accumulation of
anaesthetic vapour.
•
•
and should avoid operating rooms and animal recovery areas.
•
any spillage.
•
•
•
response very occasionally seen after repeated exposure.
•
charcoal filters with scavenging equipment.
Direct exposure to eyes may result in mild irritation. If eye exposure occurs, the eye
should be flushed with plenty of water for 15 minutes. Medical attention should be
sought if irritation persists.

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In case of accidental contact with the skin, wash affected area with abundant water.
Symptoms of human overexposure (inhalation) to sevoflurane vapour include
respiratory depression, hypotension, bradycardia, shivering, nausea and headache. If
these symptoms occur, the individual should be removed from the source of
exposure and medical attention sought.
Advice to doctors:
Maintain a patent airway and give symptomatic and supportive treatment.
Intravenous Anaesthetics:
Sevoflurane administration is compatible with the intravenous barbiturates and
propofol and in cats alfaxalone and ketamine. In dogs, the concurrent administration
of thiopental, however, may slightly increase sensitivity to adrenaline-induced cardiac
arrhythmias.
Benzodiazepines and Opioids:
Sevoflurane administration is compatible with benzodiazepines and opioids
commonly used in veterinary practice. In common with other inhalational
anaesthetics, the MAC of sevoflurane is reduced by the concurrent administration of
benzodiazepines and opioids.
Phenothiazines and alpha-2-agonists:
Sevoflurane is compatible with phenothiazines and alpha-2-agonists commonly used
in veterinary practice. have an anaesthetic sparing effect and
therefore the dose of sevoflurane should be reduced accordingly. Limited data are
available on the effects of the highly potent alpha-2-agonists (medetomidine,
romifidine and dexmedetomidine) as premedication. Therefore they should be used
with caution. Alpha-2-agonists cause bradycardia which may occur when they are
used with sevoflurane. Bradycardia can be reversed by the administration of
anticholinergics.
Anticholinergics:
Studies in dogs and cats show that anticholinergic premedication is compatible with
sevoflurane anaesthesia in dogs and cats.
In a laboratory study, the use of an
acepromazine/oxymorphone/thiopental/sevoflurane anaesthetic regimen resulted in
prolonged recoveries in all the dogs treated, compared to recoveries in dogs
anaesthetised with sevoflurane alone.
The use of sevoflurane with nondepolarising muscle relaxants has not been
evaluated in dogs. In cats sevoflurane has been shown to exert some neuromuscular
blocking effect, but this is only apparent at high doses. In humans sevoflurane
increases both the intensity and duration of neuromuscular blockade induced by
nondepolarising muscle relaxants. Neuromuscular blocking agents have been used
in cats anaesthetised with sevoflurane without any unexpected effects.
Keep the bottle tightly closed.

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Not applicable
5.

This information is sourced from the official Summary of Product Characteristics (SPC) published by the Veterinary Medicines Directorate (VMD). It is provided for informational purposes only and does not replace professional veterinary advice. Always consult your vet before administering any medication.

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