Horses.

Induction of muscle relaxation and immobilisation, as adjunct to balanced anaesthesia.

Depending on the procedure, guaifenesin can be used in combination with different anaesthetics:

- In combination with a sedative and local anaesthetics for short procedures.

- In combination with appropriate general anaesthetics for induction and/or maintenance of muscle relaxation during anaesthesia.

Guaifenesin should not be used alone. Animals must be properly sedated before immobilisation with the veterinary medicinal product. Adequate analgesia should always be provided for surgical and/or painful procedures.

Animals should undergo a thorough pre-anaesthetic examination before administration of the product. Except in the case of an acute emergency, feed should be withheld for 12 hours prior to anaesthesia. Water should be freely available until a short time before anaesthesia.

Due to the irritative effects of the solution, it should be administered strictly intravenously using a catheter. See also Adverse reactions.

Animals with anaemia, cardiac or respiratory problems, or animals with other signs of disease, should be monitored extra carefully.

People with known hypersensitivity to guaifenesin should avoid contact with the veterinary medicinal product. Take care to avoid skin or eye contact. In case of accidental skin contact wash affected area thoroughly. If irritation occurs/persists, seek medical advice. In case of accidental eye contact flush thoroughly with clean water and seek medical advice immediately, showing the product label to the physician.

Guaifenesin may lower arterial blood pressure.

Due to the irritative properties, use of the veterinary medicinal product may result in thrombophlebitis. To reduce the incidence of thrombophlebitis, the catheter can be flushed with heparinised saline. Extravascular reactions have been reported; the use of an intravenous catheter and a careful technique will help prevent such occurrences.

Guaifenesin crosses the placenta, but no short term negative effects on the foetus were observed. The safety of the veterinary medicinal product has not been established during pregnancy or lactation. Therefore, use only according to the benefit/risk assessment by the responsible veterinarian.

The action of anaesthetic agents is potentiated by guaifenesin.

For intravenous administration by catheter:

Dose: 100 mg guaifenesin per kg body weight per infusion equivalent to 100 ml solution per 100 kg body weight.

Guaifenesin can be used in combination with different anaesthetics, as follows:

Local anaesthetics for short procedures:

Once the horse is properly sedated, guaifenesin is administered by rapid infusion until the animal lies down. A local anaesthetic should be used for painful procedures. Additional guaifenesin can be infused when the horse is recumbent, if needed.

General anaesthetics:

Pre-medication with an α2-receptor agonist (e.g. xylazine, detomidine, or romifidine) or acepromazine. If guaifenesin is to be administered with ketamine, pre-medication with one of the α2-receptor agonists is recommended.

Guaifenesin is administered by rapid infusion until the animal begins to sway on its feet. At this stage either ketamine, thiopental or propofol is administered at a bolus dose. The duration of action of these combinations is variable depending on the animal and the other drugs administered. Surgical anaesthesia will be approximately 10-20 minutes duration and recumbency will be approximately 30-40 minutes duration.

Guaifenesin, administered by continuous IV infusion (50-100 mg/kg) at an infusion rate of approximately 1 ml/kg/h, can be used as part of total intravenous anaesthesia (TIVA) in combination with other injectable anaesthetics for procedures lasting up to 1 hour.

Guaifenesin can be used as adjunct to balanced anaesthesia using volatile anaesthetics for longer procedures.

Guidance on anaesthetic protocols and dosages of individual veterinary medicinal products can be found in veterinary textbooks and scientific literature.

For safe use with other pharmaceuticals, reference must be made to the relevant product literature.

Doses greater than needed to obtain recumbency may result in significant respiratory depression. Signs of overdose, e.g. extensor spasms, occur at approximately twice the therapeutic dose. The lethal dose is four times the recommended treatment dose.

Not authorised for use in horses intended for human consumption.