methadone and subutex dose equivalents

[Mister Pharmacist]

hi all,

anyone got any advice as to dose equivalents for subutex and methadone.

I know the literature states that subutex can be introduced, if the methadone dose is 30mgs, however from my experience, the key workers seem to prefer to get clients down to about 20mg before considering subutex.

The trouble is they all seem to use different starting amounts and there seem to be no consistant approach to the starting dose or at what interval clients should br reviewed!

I've spoken to Shering Plough on this a couple of times and they are vague, saying that the initial dose of subutex is 4mg ( they couldn't say what this was equivalent to in terms of an existing methadone dose) and see "how the client gets on."

They didn't seem to appreciate that this patient group are not like other patient groups, in that they are generally not likely to wait to see "how they get on", since if they go into withdrawl because the dose of subutex is not holding them until their next appointment, they will simply go out and use street drugs.

This often sets the clients treatment back months as their additional usage often escalates back up to a level where subutex is no longer a viable treatment.

If anyone has any advice/experience on dose equivalents it would be of great help

thanks

mister pharmacist

[admin]

I found this

"As a maintenance agent for opioid dependency, buprenorphine offers advantages such as a lower level of dependence and minimal withdrawal symptoms, due to its partial agonist properties at the micro-opioid receptor. Previous studies have shown 8 mg sublingual buprenorphine to be equivalent to 60 mg oral methadone in terms of retention rate and opioid-negative urine levels. "

I think the partial agonist property of buprenorphine can put a client into bad withdrawel symptoms, and is why they wait until they are on a much lower dose of methadone before starting Subutex.

I found this on the net. Try this link as well: -

http://opioids.com/buprenorphine/bupvmeth.html

Hope it helps

[krishug]

Re: methadone and subutex dose equivalents

do NOT take subs when taking methadone. you have to be in withdrawall before you take them.meth is long acting and is in ur system for much longer than smack.be VERY carefull

[Sir_Dispensalot]

Re: methadone and subutex dose equivalents

do NOT take subs when taking methadone. you have to be in withdrawall before you take them.meth is long acting and is in ur system for much longer than smack.be VERY carefull

thanks for the tips krish - most of us are familiar with the actions of methadone and its incredibly long (for an opioid) half-life.

Avoiding subutex until in the early stages of withdrawal is quite wise - i'm guessing about 48 hours from last dose of methadone before switchover to subutex.

Tony's the man in the know about this though thanks to the drug team / detox work he does and his prescribing work.

I'm guessing from your use of the 'lingo' and your profile that you're a member of the public - it's nice to see someone who is well informed on a subject giving 'lay' input!

[Pharmacologic]

Re: methadone and subutex dose equivalents

Subutex/Suboxone is a very unusual drug in many ways. Due to it's partial agonist/antagonist nature it can also be a double edge sword. When transferring to Bupe (Buprenorphine) of any formulation from a drug like Methadone (with an enormous half life) you must tread very lightly. Even mild withdrawals are not safe for some people. Usually this depends on the amount taken and the regularity of dosage. I have thrown myself into deep precipitated withdrawals when in moderate withdrawal from a drug like morphine (24 hours after last dose)

An interesting side note for Subutex/Suboxone that many in the medical profession are completely unaware of is the ability to transfer from Sub to Morphine or Heroin for a short period of time and then take Sub again within 48 hours with no precipitated withdrawal. My theory on this is that while the Bupe is still strongly bound to receptors (ie 24 hours after last dose) it's possible to take Morphine or similar drugs (at appropriate doses) and have enough bind to receptors to have significant effects. When the morphine recedes the Bupe is still in the system and bound to large numbers of receptors. Then 24 hours after the dose of morphine, Bupe can once again be taken, not bring on precipitated withdrawals due to the Bupe in the system already being bound to large numbers of receptors. (ie not pushing full agonist drugs with all those pleasurable feelings off receptors)

Conversely if Morphine or other agonists are administered for more than 48 hours after the last dose of Bupe uncomfortable withdrawals and the danger of precipitated withdrawal (even more uncomfortable..) exist. Choosing an opiate with an appropriate half life for this type of treatment/use is obviously important given the 48 hour window.

I have experienced all the above observations on my own body and there is in fact some research to back it up.

Ref: Acute Pain Management for Patients Receiving Maintenance Methadone or Buprenorphine Therapy, Daniel P. Alford, MD, MPH, Peggy Compton, RN, PhD; and Jeffrey H. Samet, MD, MA, MPH

Also of interest to the original poster: PCSS Guidance, Transfer from Methadone to Buprenorphine, Author: Paul P. Casadonte MD. This is a well referenced guide to what your inquiring about.

(just another member of public that want's to share first hand experience with these drugs that those in the medical profession, sadly will always struggle to understand without experiencing themselves)

[DavidS]

Re: methadone and subutex dose equivalents

(just another member of public that want's to share first hand experience with these drugs that those in the medical profession, sadly will always struggle to understand without experiencing themselves)

That's quite a first post. Thank you.

[Tesh]

Re: methadone and subutex dose equivalents

Quite an apt username too!

[Fleegle]

Re: methadone and subutex dose equivalents

(just another member of public that want's to share first hand experience with these drugs that those in the medical profession, sadly will always struggle to understand without experiencing themselves)

Thank-you for your overly-large copy and paste. May I be the first to inform you that no-one within the medical profession has even the slightest notion of experiencing, first-hand, your drug(s) of choice.

Post sense or go away.

[johnep]

Re: methadone and subutex dose equivalents

Shipman certainly had experience of taking pethidine.
johnep

[Jeff]

Re: methadone and subutex dose equivalents

May I be the first to inform you that no-one within the medical profession has even the slightest notion of experiencing, first-hand, your drug(s) of choice.

Bollocks

SMMGP - Library - Newsletters - Network 14 (May 2006)

BBC NEWS | Health | Addiction service to help doctors

Careers advice

And who was it just said

Post sense or go away

Jeff

[Pharmacologic]

Re: methadone and subutex dose equivalents

I find it hard to believe no doctor anywhere has ever entertained the though of experimenting with opiates. I find it easier to believe that doctors, pharmacists other health care professionals exposed to such drugs in the work place could easily get into a compromising situation. I would even go so far as to suggest it could be an occupational hazard..

Unfortunately the world is not as black and white as you suggest Fleegle.

Anyway, I hope the references provided information to professionals assisting patients to make the transition the OP was talking about.

[johnep]

Re: methadone and subutex dose equivalents

According to a list published in the PJ 13/12/2008
Methadone potency to morphine is 0.1 : 1.0, ie about 10%.
johnep

[bobbin]

Re: methadone and subutex dose equivalents

According to a list published in the PJ 13/12/2008
Methadone potency to morphine is 0.1 : 1.0, ie about 10%.
johnep

Methadone is a very potent opioid......but it's potency is very variable. A single (isolated) 10mg dose of oral methadone may be quite similar in potency to oral morphine.............but on repeated dosing methadone may be up to 10 times more potent than oral morphine. This is especially relevent to patients who are receiving very high doses of morphine for analgesia. If a transfer to methadone is contemplated due to inadequate pain control despite high-dose morphine (eg. >600mg per 24 hours), approx. 1/10 of the dose of oral morphine may be appropriate initially, adjusted according to response under close supervision. Although difficult to use due to its unpredictable pharmacokinetics, methadone remains a useful treatment for some patients with severe chronic pain, particularly when other potent opioids have been tried but rapid dose escalation has been necessary..........and possibly in patients whose pain has a neuropathic element. Although methadone is used by some pain specialists and palliative care consultants in the UK, it is used for this purpose significantly more frequently in the US........where its very low cost in comparison to controlled-release morphine, OxyContin and Durogesic is highly relevent. In the absence of an NHS, the cost of drugs is very important. Many patients are simply unable to afford high doses of expensive products such as OxyContin.

With regard to the relative potency of methadone and Subutex.........it's not really possible to come up with a figure due to the fact that methadone is a full opioid agonist whereas buprenorphine is a partial agonist. Estimates of relative potency are only appropriate for drugs which have an identical mechanism of action.

Bobbin

[Tony Schofield]

Re: methadone and subutex dose equivalents

For treating opiate dependence the maximum licensed dose of buprenorphine is 32mg. Above this dose there is no evidence of any added benefit. Methadone can be increased massively however. The biggest dose I have seen (and supervised!) was 500ml and I regularly prescribe some patients doses over 200ml. The most common doses of methadone are between 60 and 120ml but as there is a 100 fold variation on ability to metabolise methadone within the population there are big variations around those doses.

As buprenorphine is a partial agonist it can block the receptors without producing some of the effects of opiates eg euphoria, drowsiness etc. Consequently patients on buprenorphine note feeling clear headed, requiring less sleep and being alert which is not the case with methadone. Patients frequently express a preference for one drug or the other based on this experience.

Also as buprenorphine displaces opiates abruptly from receptors whilst not producing many of the effects (as stated above) of opiates it can precipitate withdrawal symptoms which is deeply distressing for the patient. Hence only initiating buprenorphine when the patient is in withdrawal already.

The drugs do not have directly equivelant doses. So whilst starting a patient on titration with 30ml of methadone mirrors starting a patient on 4-8mg of buprenorphine, they are safe starting points not equivelant doses. So 18mg of buprenorphine would be impossible to translate into an equivelant methadone dose.

Buprenorphine is the first line drug in France.

[Fleegle]

Re: methadone and subutex dose equivalents

Bollocks


Jeff

Thank-you for the eloquence of your reply Jeff. I await your next post with indifference.

Fleegle.