RSO. different strains are different though, the same as flower, so maybe try a few different ones. gassed's is a nice, relaxing medicinal feeling indica, tasty too, rocketdogronnie's FECO is expensive but worth it, black gold's RSO is excellent value and very very strong but there are a few choices on lb - someone has mentioned some others in another comment. perhaps, if RSO works well for her, your friend could build a relationship with one of the smaller, friendlier, maybe less established vendors on lb (there are a few) and experiment with different strains to find the most effective. i know that if i was a vendor i would very much want a long term regular repeat customer like her, and the opportunity to experiment with different strains and extraction techniques which i could then market to other long term sufferers along with useful advice and information gleaned would be invaluable. a goldmine, surely?
if your friend were to take too much RSO (which will almost certainly happen at some point - count on it) it could be fairly unpleasant (especially for an inexperienced user - panic attacks can happen) but some sort of strong CBD product, a couple of 1200mg capsules from holland and barrett or something, will make everything better in about fifteen minutes. keep some handy and your friend will always be fine while she experiments (it is hard to get the dose right and the correct dose can fluctuate, too, so get her to hold on to the caps. if she ever takes too much CBD, nothing particularly will happen. blocked ears, maybe?).
cannabis tends to lower blood pressure, but it can cause it to temporarily spike too (much less likely with rso than smoking or vaping i think - a slower, steadier delivery), whether that's going to be a problem with AF or not i don't know - it's probably best to start small but honestly, it's got to be worth trying. it might even help with the AF, i suppose she'll have to see for herself. chronic pain can make life hardly worth living, and morphine is not nice. diamorphine is, but it's pretty bad for you. opiates/opioids and cannabis do tend to kind of reinforce each others effects, though, so the combination of RSO and whatever she's on now might tend to knock her out a bit at first, or make her very stoned. this will get better, especially if the RSO is effective enough to allow her to back off on the codeine or whatever it is.
just a word on tolerance - i don't know what sort of dose your friend's going to need, but unless the dose is very low tolerance is likely to build up over time. unlike opiate and opioid medication, it can be very effectively and quite easily reversed by just stopping taking rso for two or three weeks - remember with very very high doses your friend will need to ease off gradually, lower doses she can just stop and it'll be fine - hit the prescription medication a bit harder for a short while and then the rso will start working again just as well as when she first started. four weeks for a total reset, two or three will be most of it though. if it seems like consumption is creeping up, it might not be the arthritis getting worse, try having a tolerance break.
i hope this all helps. opiates/ioids are actually pretty useless at dealing with long term pain, if the RSO works effectively enough - and i hope it does - i would suggest coming off them completely (really slowly - cut down gradually over months and months), then they will work well again for a while at least if things ever get really really bad and she needs them. also, morphine is - subtly so, but nonetheless - quite nasty. it is a powerful hypnotic and although a far from unpleasant feeling, whole days can go missing on it. it is well worth faking a bad reaction to it to get diamorphine instead, but neither are really effective for long term pain and they are both quite toxic and highly addictive, even if they do work a treat in the short term. make sure she keeps taking the paracetamol, though, it does a lot more than you think.
p.s. don't apologise for the long message, it is good to have this information up there for other biggas. if your friend ever wanted to post about her experiences with RSO/FECO and pain, good or bad, i'm sure others would find it very helpful. most of us are stoners, so a different perspective would be welcome.
