Fentadon 50 Microgram/ml, Solution for Injection/Infusion for Dogs

Composition

Each ml contains:

Active substance:

Fentanyl: 50 microgram

(equivalent to 78.5 microgram of fentanyl citrate)

Excipients:

Clear, colourless solution.

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Pharmacological properties

4.1 ATCvet code: QN02AB03

4.2 Pharmacodynamics

Fentanyl is a synthetic opioid that is selective for the µ-opioid receptor. Fentanyl citrate has the ability to produce profound analgesia. It causes only minor heart and circulatory depression.

The principal actions of therapeutic value are analgesia and sedation.

Following intravenous injection fentanyl has a rapid onset of action, although the maximal analgesic and respiratory depressant effects may not occur for several minutes.

4.3 Pharmacokinetics

After intravenous injection the fentanyl plasma concentrations decrease rapidly primarily due to redistribution. In dogs, fentanyl is 60% bound to plasma proteins. Fentanyl has a large volume of distribution of more than 5 l/kg. The plasma kinetics of fentanyl are independent of the dose in the range of recommended doses.

Fentanyl has a relatively long elimination half-life: 45 minutes to more than 3 hours in dogs. The clearance is high about 40 to 80 ml/min/kg. It is primarily eliminated by metabolism, with hydroxylation and dealkylation being the primary mechanisms, and less than 8% of the total dose is eliminated as unchanged drug. In addition to hepatic metabolism fentanyl may be metabolised in extra hepatic sites and eliminated by extra renal routes.

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Target species

Dogs.

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Indications

For intra-operative analgesia during surgical procedures such as soft tissue and orthopaedic surgery.

For the control of post-operative pain associated with major orthopaedic and soft tissue surgery.

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Dosage

For intravenous use.

To ensure a correct dosage, body weight should be determined as accurately as possible. Onset of action is seen within 5 minutes. The duration of the analgesic effect is 20 (lowest recommended dose) to 40 minutes (highest recommended dose).

Fentanyl can be administered according to the following dosage regimen:

Analgesia by Continuous Rate Infusion (CRI)

• 5 – 10 µg/kg (0.1 - 0.2 ml/kg) IV as a bolus, followed by 12 – 24 µg/kg/hr (0.24 - 0.48 ml/kg/hr) IV for intra-operative analgesia as CRI.

• 6 – 10 µg/kg/hr (0.12 - 0.2 ml/kg/hr) IV for subsequent post-operative analgesia as CRI in sedated animals. During post-operative CRI administration of fentanyl, animals should be monitored carefully.

Chemical-physical compatibility has only been demonstrated for dilutions 1:5 with the following solutions for infusion: sodium chloride 0.9%, Ringer’s solution and glucose 5%.

The veterinary medicinal product has a narrow margin of safety and it is important to measure the dose accurately to avoid overdosing.

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Contraindications

Do not use in cases of hypersensitivity to the active substance, or to any of the excipients.

Do not use in dogs with cardiac failure, hypotension, hypovolaemia, obstructive airway disease, respiratory depression, hypertension or with a history of epilepsy.

Do not use in animals with severe liver or renal dysfunction.

Refer to sections 3.7 and 3.8.

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Adverse reactions

Dogs:

Very common (>1 animal / 10 animals treated): Hyperactivity, Irritability, Vocalisation, Involuntary defecation, Tongue protrusion, Vomiting, Tremor a, Sedation, Urination, Increased respiratory rate, Panting, Scratching

Common (1 to 10 animals / 100 animals treated): Respiratory depression b, Bradycardia c, Hypotension d

Uncommon (1 to 10 animals / 1,000 animals treated): Hypothermia

Rare (1 to 10 animals / 10,000 animals treated): Lowered nociceptive thresholds e

a Tremors of the body.

b Can be of long duration and may exhibit a biphasic pattern.

c Due to increased cardiac vagal stimulation.

d Transient. Following intravenous administration of fentanyl citrate even at doses of 2.5 – 5 μg/kg.

e When the effects of the drug dissipate.

Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.

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Warnings

Special precautions for safe use in the target species:

If other narcotic or CNS-depressant drugs (e.g. propofol, isoflurane, sevoflurane) are used concurrently with fentanyl the doses of these agents may need to be reduced.

As a class, opioids, including this veterinary medicinal product, may cause hypothermia with duration related to dose, bradypnea, hypotension and bradycardia. Therefore, animals should be continuously monitored for rectal temperature, pulse rate, respiratory rate and heart rhythm during surgical anaesthesia.

In case of renal, cardiac or hepatic dysfunction, hypovolaemia or shock, there may be greater risk associated with the use of the product. It is desirable to reduce dosage in case of hypothyroidism and in case of chronic hepatic or renal disease. As with all narcotic analgesics, care should be taken when administering fentanyl to animals with myasthenia gravis.

Facilities for the maintenance of a patent airway, intermittent positive pressure ventilation (IPPV) and oxygen supplementation should be available. When respiratory depression occurs, controlled ventilation should be installed.

As with all potent opioids, profound analgesia is accompanied by respiratory depression, which may persist into or recur in the early post-operative period. The respiratory depressant effects may be more problematic in animals with pre-existing respiratory disease or increased intracranial pressure. The effect of an opioid on head injury is dependent on the type and severity of the injury and the respiratory support supplied. It is imperative to ensure that adequate spontaneous breathing has been established and maintained before discharge from the recovery area whenever large doses of infusions of fentanyl have been administered. The benefit/risk ratio for using the veterinary medicinal product should be made by the attending vet. The pharmacological effects of fentanyl citrate can be reversed by naloxone.

Special precautions to be taken by the person administering the veterinary medicinal product to animals

Fentanyl, an opioid, may cause adverse effects after internal exposure, including respiratory depression or apnoea, sedation, hypotension and coma.

The veterinary medicinal product may cause hypersensitivity reactions. Avoid contact with the skin and eyes. Personal protective equipment consisting of protective gloves should be worn when handling the veterinary medicinal product. Wash hands after use. Wash any splashes from skin and eyes immediately with large amounts of water. Remove contaminated clothes.

Care should be taken to avoid accidental self-injection. In case of accidental self-injection, seek medical advice immediately and show the package leaflet to the doctor but DO NOT DRIVE as sedation may occur.

Adverse effects on the foetus cannot be excluded. Pregnant women should avoid handling the veterinary medicinal product. In case of women who are breastfeeding being accidentally exposed, breastfeeding is discouraged for 24 hours, as fentanyl may transfer to breast milk.

To the physician:

Fentanyl is an opioid whose toxicity may cause clinical effects, including respiratory depression or apnoea, sedation, hypotension and coma. When respiratory depression occurs, controlled ventilation should be installed. Administration of the opioid antagonist naloxone to reverse the symptoms is recommended.

Special precautions for the protection of the environment:

Not applicable.

3.11 Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance

For administration only by a veterinarian.

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Use during pregnancy, lactation or lay

Pregnancy and lactation:

The safety of the veterinary medicinal product has not been established during pregnancy and lactation. The use of the product is not recommended during pregnancy or lactation.

Laboratory studies in rats have not produced any evidence of a teratogenic, foetotoxic or mutagenic effect. Placental transfer of fentanyl occurs. Administration during parturition may cause respiratory depression in the foetus.

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Interactions

Fentanyl is a potent anaesthetic sparing substance. To avoid anaesthetic overdose in dogs treated with the veterinary medicinal product, anaesthetic agents should be administered only until the desired effect is produced.

The veterinary medicinal product should be used with caution in conjunction with morphine or other opioid type analgesics as the effects have not been studied.

The effects of the concomitant use of the veterinary medicinal product and α-adrenergic agonists have not been studied. Therefore, α2-adrenergic agonists should be used with caution in animals dosed with the veterinary medicinal product due to potentially additive or synergistic effects.

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Overdose

A 2 fold overdose as a bolus injection resulted in the effects mentioned in section 3.6. In the event that any of the following observations are made following the application/overdose of the veterinary medicinal product, reversal should be initiated: severe sedation, unconsciousness, seizures, laboured or abdominal breathing or severe hypotension. The specific narcotic antagonist naloxone hydrochloride can be used to counteract respiratory depression. A dose of 0.01 to 0.04 mg/kg is given intravenously and may be repeated at intervals of 2 to 3 minutes if necessary.

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Special warnings

The use of this veterinary medicinal product must be preceded by a thorough clinical examination. Atropine may be used to block the vagal effects.

This veterinary medicinal product should be titrated for the individual animal to an effective dose that provides adequate analgesia and minimises undesirable effects. Animals should be carefully monitored until an effective dose is reached. Due to individual differences in pain sensitivity, the effects of fentanyl may be variable. Older animals may tend to titrate to a lower effective dose than younger animals. It is important when estimating the required dose for intra-operative analgesia to assess the likely degree of surgical stimulation, the effect of premedication drugs, whether supportive care like endotracheal intubation and ventilatory support may be required, and the duration of the procedure.

If other narcotic or CNS-depressant drugs (e.g. propofol, isoflurane, sevoflurane) are used concurrently with fentanyl the doses of these agents may need to be reduced. When estimating the required dose for post-operative analgesia the degree of tissue damage has to be assessed.

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Withdrawal period

Not applicable

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Incompatibilities

Do not mix with any other veterinary medicinal product except the infusion solutions indicated in section 3.9.

The veterinary medicinal product is incompatible with injection fluids containing meloxicam or any other non-aqueous solution.

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Immediate packaging

Vials of uncoloured glass type I, filled with 5, 10, 20, 25, 30, 50 and 100 ml.

Teflon-coated chlorobutyl rubber stoppers type I secured with aluminium caps.

Pack sizes:

Cardboard box containing one vial of 5, 10, 20, 25, 30, 50 or 100 ml.

Not all pack sizes may be marketed.

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Storage

Do not freeze.

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Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 3 years. Shelf life after first opening the immediate packaging: 28 days.

Chemical and physical stability of the dilutions (as indicated in section 3.9) has been demonstrated for 4 hours at 25 °C. From a microbiological point of view the dilutions should be used immediately.

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Disposal of unused product

Medicines should not be disposed of via wastewater.

Use take-back schemes for the disposal of any unused veterinary medicinal product or waste materials derived thereof in accordance with local requirements and with any national collection systems applicable to the veterinary medicinal product concerned.

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Additional information

Vm 16849/3014

Vm 16849/5014

8 DATE OF FIRST AUTHORISATION

27 February 2012

9 DATE OF THE LAST REVISION OF THE SUMMARY OF THE PRODUCT CHARACTERISTICS

November 2024

10 CLASSIFICATION OF VETERINARY MEDICINAL PRODUCT

Veterinary medicinal product subject to prescription.

Find more product information by searching for the ‘Product Information Database’ on www.gov.uk.

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Registration holder

Eurovet Animal Health B.V.

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