From what swim
has been able to find out, a 75µg/h transdermal fentanyl
patch roughly equates to somewhere around 100mg of methadone
over a 24 hours period. As ever, opiate
conversion ratios can vary greatly from one to the next, but this seems to be the average equianalgesic dose stated.
So you really shouldn't be needing to top up with any methadone at all. In fact, swim would say it'd be rather dangerous to do so.
Transdermal fentanyl patches deliver the set dose (in this case, 75µg/h) every hour for 72 hours, that is to say three days. After this, they will continue to deliver fentanyl, but the dosage isn't guaranteed.
Why are you using a fentanyl patch instead of your methadone? It is very unlikely that you will gain any euphoric narcotic effects from it, and swim would think that a steady methadone script would hold you better, in terms of staving off withdrawal
. Certainly will be better than stopping and starting taking methadone, and swapping between it and other opiates
. If keeping yourself well is your only concern (and you're not trying to get off on the fent), then swim's advice would be to stick to the meth
- it has a long half life, and so keeps the levels in your body as steady as possible. This is why it's used for opiate substitution maintenance, I guess.