Target species
Dogs.
Indications for use for each target species
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.
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 Use during pregnancy, lactation or lay and Interactions.
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.
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.
Adverse events
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.
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.
Interaction with other medicinal products and other forms of interaction
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.
Amounts to be administered and administration route
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.
Symptoms of overdose (and where applicable, emergency procedures and antidotes)
A 2 fold overdose as a bolus injection resulted in the effects mentioned in Adverse reactions. 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.
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.
Withdrawal periods
Not applicable