Hi Paul,
It's never too late.
Many of us have been dependent on Solpadeine for decades. It's great that you have noticed a problem after only two years and are determined to tackle it.
That terrible restlessness you are experiencing is a classic Solpadeine withdrawal symptom. If you look through old posts, you will notice that lots of people here have suffered from it. They might have tips on how to handle it. It goes away after a few days (less than a week) once the drug is out of your system.
Other classic withdrawal symptoms include headaches and migraines, nausea and vomiting, and lower back pain. The lower back pain can be helped by physiotherapy and/or Pilates (a small class run by a qualified physiotherapist to make sure you're doing it right).
I am also a headache/migraine sufferer. That's why I started taking Solpadeine when I was 16 (I'm now 50). When I quit Solpadeine, I had a withdrawal migraine. It lasted 4-5 days - pain, nausea, vomiting, the works, but after it was over I felt SO much better, so clean, that it was worth the pain and misery.
For headache/migraine sufferers, it is worth quitting all sources of caffeine at the same time: coffee, tea, chocolate, energy drinks, Coke, Solpadeine, Excedrin, Panadol Extra, etc. Caffeine is a real problem for headache/migraine sufferers, from long personal experience. Staying away from all sources of caffeine can drastically lessen the number of headaches and migraines you suffer overall.
Once your body is used to life without caffeine, it starts producing its own energy, especially if you eat lots of fruit and vegetables and drink plenty of fresh, still water (fizzy water is a problem for me, headache-wise). Being caffeine-free should help with anxiety levels, too. So does exercise, as it helps burn off adrenaline and other chemicals in the body that contribute to feeling anxious.
Don't let any fear of withdrawal headaches/migraines stop you from quitting. You are young. You have been dependent on Solpadeine for only two years. I suspect your withdrawal headache, if you have one, won't last as long as mine did.
I'm not a medic, and only a doctor can answer your question about the liver, but I would hazard a guess that you have done little damage to your liver so far. Why? You have remained within the daily maximum dose on the box (8) and you have left four hours between doses, as per the instructions. You are right to quit now, though, before any serious damage is done. (I'm sure you know never to take other products containing paracetamol (Lemsip, Panadol, etc.) alongside Solpadeine; if you do that, you will be overdosing on paracetamol.)
My body doesn't like cutting down. When I have tried to do so, it has thrown me into cold turkey. But withdrawal symptoms don't last very long. It's different for everyone but they last me the guts of a week: 4-5 days for the headache/nausea, then a few 'aftershock' headaches that I try to manage by drinking lots of water. Once that's over, I feel great - way better than I did before I started quitting. It's also important to eat very simple food if you are hungry during withdrawal. I find the safest foods to be brown rice, steamed courgettes and watermelon chunks. Eating complex meals (even a soup made with chicken stock or something) can make the withdrawal headache a lot worse, in my experience. I have no idea why!
A word of warning: in the past, I got re-hooked on Solpadeine several times due to lower back pain (before I went to a physiotherapist) and 'aftershock' headaches. I remember having a busy day ahead and saying, 'OK, I'll just take one to get me through it.' And it would work, but then I'd have another headache the next day and I'd do the same thing. Before I knew it, I was back up to six a day. So it's really important NOT to give in to taking Solpadeine once you are clean because it creeps up again in no time.
Solpadeine and other painkillers also CAUSE headaches and migraine if taken regularly, as you have been doing. Solpadeine is a particularly bad culprit. A neurologist at my local migraine clinic told me never to take Solpadeine for headache/migraine. The brains of people with headache disorders are wired up differently: painkillers can cause headaches and migraines when used regularly. They should only be used occasionally and sparingly, if at all. There are natural ways of preventing and even treating headaches and migraines through a clean diet, hydration, exercise, meditation, etc.
Cold turkey and cutting down both have merits and demerits. Sounds like you know what cold turkey feels like already. If you want to cut down, in my experience the tortoise beats the hare. Go too fast and you'll likely trigger a migraine and end up back where you started. If you go slowly, try cutting down by 1/4 of a tablet a day. Or even less, if you start getting headaches. Due to the caffeine content of Solpadeine (caffeine withdrawal is a notorious migraine trigger), I'd suggest something like this:
Day 1: chop 1/4 off your second dose of the day
Day 2: chop 1/4 off your first dose
Day 3: chop 1/4 off your third dose
Day 4: chop 1/2 off your second dose
Day 5: chop 1/2 off your first dose
Day 6: chop 1/2 off your third dose
Day 7: chop 3/4 off your second dose… and so on
That way, you lessen your caffeine intake 'horizontally', which is less likely to trigger a headache.
Cutting down slowly, if your body allows you to do so, requires discipline. You need to make sure you don't go 'up' again on any given day. But it also gives your mind time to adjust to coming off Solpadeine, which cold turkey doesn't do.
The main thing is to do what works best for you, and only you can work that out.
I hope some of that helps…
Kind regards,
Storm