Question: I am 66 years old and have had ME/CFS since 1990, went down with third bad bout 4/5 months ago, having been since 1999 (last bad bout) on Venlafaxine 2 x 37.5mg a.m. + Dosulepin 2 x 25mg p.m. which few years ago reduced to 1 x 25mg p.m. but reinstated to 2 x 25 about 3 months ago because of ME/CFS relapse. Gradual recovery from latter being hindered by bouts of anxiety which set me back so psychiatrist has recommended changing from Dosulepin 50mg nocte to Mirtazapine 15mg nocte which I can see makes sense. However, he recommends simply swapping i.e. stop D one day then start M next because in his opinion 50mg Dosulepin is low dose (I hadn't realised that) whereas I've read online about 'cautious cross tapering' or reducing to say 25mg D before ditching and starting 15mg M. I completely trust this very experienced doctor but live on my own and am frightened of any serious reaction if I simply stop/start like this. I score 7/21 on depression scale and 13/21 on anxiety scale but it's the anxiety which is noticeable though haven't had bout now for about ten days (I just cry and despair for ca 3 days, fearing no ME recovery whereas I've done so twice before so this isn't rational, which I accept). I can cope with side effects with aid of temporary diazepam BUT am concerned this 50mgD to 15mg M might be dangerous (anxiety again, there you see it). Is there any hard and fast rule that you know of? I could certainly do with the extra sleep from the M.

Thank you for your first answer above : very much appreciated. I am already in process of reducing from 50 to 25 mg Dosulepin just in case (which I have done before) I change but still have reservations about change so would like to ask following additional questions please in view of fact that my mood and other symptons are continuing to improve and I want to keep my options open, combi of V 75 + D 25 -50 having suited me so well for so long :

1. I am now 66, no longer 52 as when I started V/D combi. I have to keep things in proportion BUT (big BUT!), given that I'm not changing V dose at all, is there a greater risk of developing Serotonin Syndrome by changing from D to M? I realise that M is a ?tetracyclic, as opposed to SSRI, but have no wish to increase any risk of XXXXXXX I can in due course manage on 25mg D as I did until couple of months ago and my mood is now improving all the time as I realise that I have regained control of my mood and must be happy with any changes. XXXXXXX is my greatest concern and I have no wish to risk it.

2. I've taken only low dose Dosulepin all these years specifically as a 'nerve blocker' to control pain and it has worked well, as has e.g. Amitryptiline (can't spell) for others. I can find no mention of Mirtazapine anywhere online or in latest ME/CFS info literature being useful for pain management, have no wish to change to it then have to add in another pain killer (my pain was classed years ago as moderate to severe, hence having to upgrade to D to sort it which it did whereas NSAIDS etc. didn't touch it!] Wd M be a likely to block 'neuropathic' pain as D has been? [OF COURSE I realise we're all individual and that this may be impossible to answer!]

3. I'm overweight, have recently managed to lose one stone 13.5 to 12.5 which I have no wish to regain. Psychiatrist fairly warned me about weight gain but is this peculiar to M? I've 'sensibly' (i.e. slowly) lost one stone over ca 6 months and if I pile weight back on that will depress my mood again anyway! I'm also prepared to do some course e.g. Mindfulness to address anxiety which have always managed to do in the past. So, will M make me more likely to regain weight?

Re 'significant weight gain' you refer to, I wonder whether there's any way of knowing whether that's more or less likely to apply to me. I always weighed 8.5 stones but early '90s didn't take me long to put on 4 stones when put on Nardil 1991 then changed to Parstelin 1993, both in conjunction with good old Dosulepin 50. Came off Parstelin mid '90s but stayed on Dosulepin 50, then put onto Venlafaxine on ME relapse 1999, struggled with weight ever since, stuck to low sat fat and no sugar diet, not big eater. Since 2001, have been on 5mg Amlodipine for raised blood pressure which weight gain would not help! I can't say for sure that medication caused all that weight gain but even when I managed to play tennis again (1994 - 1999) almost every day I could never lose it! So, given that AntiDs piled on all those pounds which have only recently started to reduce, am I a likely candidate for piling on even more on Mirtazapine however strict I am about how and what I eat? I've been able to be VERY disciplined about diet, loads of will power (e.g. reduced cholesterol from 6.9 to 3.2 in 18 month just by rigidly changing diet) but is it possible that however strict I am I'll nevertheless pile on stones if change to M? [I'm less concerned about sedation as presumably that will reduce as time goes on and it's hardly as potentially damaging as putting on another 4 stones.] Thanks so much for any further inspiration.......................

Hello and thank you for asking........................my anxiety subsided so I decided not to change pills and to do a Mindfulness course first BUT just over week ago everything went wrong (never got to start course) : crying, nausea, severe anxiety, worse than before, lasted about six days. There was no way I cd start course and although I've only reduced now to 1.5 tabs (37.5 Dosulepin) I'm left with no option and am planning to swap over this coming Wednesday evening when my son can come and stay overnight and be with me next day. From what I've read, Mirtazapine is safer than Dosulepin and I only hope it will be better for anxiety. I just don't have health or strength to get down to 25mg, am frightened of rebound effects and can only hope doing 37.5mgD to 25mgM won't be too ghastly. ANY tips you might have as to how to handle changeover wd be gratefully appreciated and of course I'd pay another fee! I'nm no longer worried about serotonin syndrome and am also wondering if I may be able to deal with any rebound symptons with aid of Diazepam which I have here as muscle relaxant, have used on and off for many years since 1990 and to which have never become addicted : just used as and when and very rarely indeed until couple of months ago. I realise I'm being over anxious and that I may have no unbearable symptons at all. Thank you in advance for any further tips.

I should have added that I'm hoping the continuing 75mg Venlafaxine might protect me to some extent against rebound symptons : with ME/CFS I'm well used to things like rebound sweating, fatigue, dizziness and so on and can cope with those. In UK they're trying to get us off Dosulepin (?cardiac/dementia/whatever?) and I've recently heard of people reducing from 150 to 80 then having to transfer straight onto e.g. Citalopram........................I'm extra cautious I suppose having used Dosulepin since 1990 (never more than 50mg for pain control) but M may be better for anxiety, so all I can do is hope.

Thank you so much : what I would call 'cautious cross tapering' is exactly what I wanted to do but both GP and psychiatrist have again said just stop D37.5 one night then start M15 next night....................................they said no problem cos doses so low : I guess if I have real problems it will be possible to introduce what wd have been my tapering regime, just as you've described above? That wd involve presumably reintroducing very low D dose and combining it with lower M dose of say 7.5?? They just seem to be assuming I won't have any adverse effects ....................... I can cope with sweating, tiredness, just don't want things like seizures, collapsing etc. because of living alone........................maybe I'm being too dramatic because of reading patient information leaflet which is frightening about rare effects etc.?? Maybe they just want to get the M into my system asap?