anyone got good knowledge on methadone?

Re: anyone got good knowledge on methadone?

B Mrs — Tue, 30 Oct 2012 10:34:06 GMT

We use it as a pre med and post op analgesia. General doses range 0.2-0.4 mg/kg dependent on patient and the surgery. We tend to get a few patients with bradycardia as a side effect which we monitor and treat with atropine. We use meth with acepromazine. Doses again dependant on patient and surgery, generally 0.01-0.03mg/kg. Really like it as analgesia. We will sometimes use as CRI in orthopaedics, leg amps or similar. We are a reproduction clinic and we dont use meth in C-sections (we do at least 3 a week) we give the bitch post op buprenorphine. I find we can use sl lower doses iso with our methadone pre medicated patients. We avoid methadone in any patient with respiratory depression. We give routinely to spays and lumpectomies etc. probably just the cat castrates as the routine surgeries that we dont give methadone to as a pre med.

Re: anyone got good knowledge on methadone?

Rachael_24 — Sat, 27 Oct 2012 17:23:15 GMT

We use methadone as part of a standard pre-med at a dose rate of 0.3mg/kg (unless there is any reason not to). We also then use it for post-op analgesia at the same dose rate every 4-6hours. If a patient goes flat on it or if we don't feel that they require that level of analgesia then we may reduce the dose or change to buprenorphine. I'm not aware of any reason not to use it in caesareans although I do believe it crosses the placenta so I guess this could be a consideration...

Re: anyone got good knowledge on methadone?

F1chick — Sat, 27 Oct 2012 13:30:01 GMT

0.1-1mg/kg (dog)

0.1-0.2mg/kg (cat)

IM, (SC, slow IV)

Re: anyone got good knowledge on methadone?

Mark Hedberg — Sun, 21 Oct 2012 20:41:54 GMT

From www.noahcompendium.co.uk/Dechra_Veterinary_Products_Ltd/Comfortan_ACY-reg_ADs-_10_mg_ml_Solution_for_Injection_for_Dogs_and_Cats/-56234.html

Re: anyone got good knowledge on methadone?

Mark Hedberg — Sun, 21 Oct 2012 20:41:25 GMT

Sorry for the long text - from

[quote]

Clinical particulars

Target species

Dogs and cats.

Indications for use

- Analgesia in dogs and cats.

- Pre-medication for general anaesthesia or neuroleptanalgesia in dogs and cats in combination with a neuroleptic drug.

Contraindications

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

Do not use in animals with advanced respiratory failure.

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

Special warnings for each target species

Due to the variable individual response to methadone, animals should be regularly monitored to ensure sufficient efficacy for the desired effect duration.

Use of the product must be preceded by a thorough clinical examination.

In cats pupil dilatation is seen long after the analgesic effect has disappeared. It is therefore not an adequate parameter to assess clinical efficacy of the administered dose.

Greyhounds may require higher doses than other breeds to achieve efficacious plasma levels.

Special precautions for use in animals

Methadone may occasionally cause respiratory depression and as with other opioid drugs, care should be taken when treating animals with impaired respiratory function or animals that are receiving drugs that can cause respiratory depression. To ensure safe use of the product, treated animals should be monitored regularly, including examination of heart rate and respiratory rate.

As methadone is metabolised by the liver, its intensity and duration of action may be affected in animals with impaired liver function. In case of renal, cardiac or hepatic dysfunction or shock, there may be greater risk associated with the use of the product. The safety of methadone has not been demonstrated in dogs less than 8 weeks and cats less than 5 months of age. The effect of an opioid on head injury is dependent on the type and severity of the injury and the respiratory support supplied. Safety has not been fully evaluated in clinically compromised cats. Due to the risk of excitation, repeated administration in cats should be used with care. The benefit/risk ratio for using the product should be made by the attending veterinarian.

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

Methadone can cause respiratory depression following spillage on the skin or accidental self-injection. Avoid skin, eye and mouth contact and wear impermeable gloves when handling the product. In case of spilling on the skin or splashing in the eyes, wash immediately with large amounts of water. Remove contaminated clothes.

People with known hypersensitivity to methadone should avoid contact with the veterinary medicinal product.

Methadone has the potential to cause stillbirths. Pregnant women are advised not to handle the product.

In the case of accidental self-injection, seek medical advice immediately and show the package leaflet to the physician but DO NOT DRIVE as sedation may occur.

ADVICE TO DOCTORS: Methadone 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.

Adverse reactions

Cats: Respiratory depression may be seen. Mild excitatory reactions have been observed: lip licking, vocalisation, urination, defaecation, mydriasis, hyperthermia and diarrhoea. Hyperalgesia has been reported. All reactions were transient.

Dogs: Respiratory depression may be seen. Mild reactions have been observed: Panting, lip licking, salivation, vocalisation, irregular breathing, hypothermia, fixed stare and body tremors. Occasional urination and defaecation can be seen within the first hour post dose. All reactions were transient.

Use during pregnancy and lactation

Methadone diffuses across the placenta. Studies in laboratory animals have shown adverse effects on reproduction. The safety of the product during pregnancy and lactation has not been assessed in the target species. The use of the product is not recommended during pregnancy.

Interactions

For concurrent use with neuroleptics refer to Amounts to be administered and administration route. Methadone can potentiate the effects of analgesics, central nervous system inhibitors and substances that cause respiratory depression. Concomitant or subsequent use of the veterinary medicinal product with buprenorphine may lead to lack of efficacy.[/quote]

Re: anyone got good knowledge on methadone?

wilkoannie — Sun, 21 Oct 2012 19:48:02 GMT

[quote user="F1chick"]

I'll fish out the info I have on it. I don't know bout sections, never ued it on them!

[/quote]

Thank you that would be very useful.

Re: anyone got good knowledge on methadone?

F1chick — Sun, 21 Oct 2012 12:27:23 GMT

I'll fish out the info I have on it. I don't know bout sections, never ued it on them!

Re: anyone got good knowledge on methadone?

hobbits — Sat, 20 Oct 2012 22:05:56 GMT

wilkoannie:

we use it as steph said. We will always use it over morphine in GDV pre surgery as it doesnt seem to cause the nausea.

If you want further information, then it may be an idea to source it yourself - you will learn more that way and know that the information is valid :)

The manufacturer would be a good place to start - they should be able to provide you with plenty of data on use - including in c-sections!

Re: anyone got good knowledge on methadone?

Steph Worsley — Sat, 20 Oct 2012 20:28:11 GMT

Sorry I wont say I'll get you any more info as I will probably not get the opportunity to speak to the anaesthetists in depth about it (and remember it) as we are all extremely busy at the minute and it's hard to get time to speak to them about anything apart from inpatients. sorry

Re: anyone got good knowledge on methadone?

wilkoannie — Sat, 20 Oct 2012 19:55:01 GMT

[quote user="Steph Worsley"]

I personally only use it as pain relief (although anaesthesia do use it as part of a premed protocol in some situations but I don't know what and what doses so can't comment on that side of it)

Pain relief wise we use a dose rate of 0.1-0.3mg/kg every 4-6 hours usually going for 0.2mg/kg every 4 hours However this dose can sometimes knock them flat so we do sometimes drop it to 0.1mg/kg or drop the rate to q6hours

[/quote] thanks for reply.. If you can find out anymore for me regarding pre meds would you let me know. many thanks

Re: anyone got good knowledge on methadone?

Steph Worsley — Sat, 20 Oct 2012 19:41:12 GMT

I personally only use it as pain relief (although anaesthesia do use it as part of a premed protocol in some situations but I don't know what and what doses so can't comment on that side of it)

Re: anyone got good knowledge on methadone?

wilkoannie — Sat, 20 Oct 2012 18:49:49 GMT

what dosages do you use?

what are the side effects?

do you use it for caesarians?

thanks for replying? [quote user="F1chick"]

The manufacturer doses ae too high, don't use them!

It is a really good premed imo, I like it, smooth induction/recovery, I like it alot!

[/quote]

Re: anyone got good knowledge on methadone?

F1chick — Sat, 20 Oct 2012 18:11:46 GMT

The manufacturer doses ae too high, don't use them!

It is a really good premed imo, I like it, smooth induction/recovery, I like it alot!