MGA News Summer 2004

General Points

1. Since each patient is different, we can only give general answers. It would be wrong for us to give individual advice (e.g. on treatment) without knowing all the details (e.g. drug allergies) - which the patient's own Neurologist and GP should have.
   
   
2. In autoimmune MG and LEMS, the antibody attack cuts down the reserve capacity in the nerve -> muscle triggering. When patients' reserves are low, they are more vulnerable to upsets like infections and certain drugs. On the other hand, if their damaging antibodies have been brought under control (e.g. with steroids), and their reserves have had time to build up again, then they may well withstand the same hazards without trouble.
   
   
3. Certain drugs are suspected of making MG worse or causing serious side-effects but have never been proved guilty. So, in deciding whether to use them, one always has to balance both the need for them and their known benefits against such potential snags.

Specific Questions:

1. Any advice about long-haul air travel?
   
   We don't expect special problems in MG. The general advice - to drink plenty of water, keep mobile and perhaps wear elastic stockings (to help the blood circulation in the legs) - is especially important for those over 40 and those taking steroids.
   
   
2. Any advice about what vaccines patients can take?
   
   Patients who are taking immunosuppressive drugs (e.g. steroids, azathioprine, and methotrexate) should only take killed vaccines or bacterial products like tetanus toxoid. Live (attenuated) germs can get out of hand in heavily immuno-suppressed people. In patients not taking such drugs, any vaccine should be safe, even after a thymectomy.
   
   
3. Any ideas about diets and alternative measures?
   
   Obviously, in general, it is wise to eat a balanced diet and not to get overweight, so as not to overstrain the muscles. If the MG is well controlled, moderate amounts of alcohol are fine: if not, then the MG can get worse. By their very nature, it is very hard to do controlled trials to prove that any particular alternative therapies, or especially any diets, are good for MG. So we have no hard evidence like we do for orthodox drugs. However, individual patients may well find something that seems to work for them, so there is probably no harm in trying. As far as we know, most available therapies are harmless, though some imported ones are said to contain steroids or heavy metals, so watch out.
   
   
4. Would taking thyroxine upset my MG?
   
   No, rather, it should help (as long as you don't take far too much).
   
   
5. About Mestinon
   
   
   1. Are there any alternatives to Mestinon® if it is not a success?
      
      Yes, there is also neostigmine, but it works very similarly, and is shorter-acting, so it is seldom much of an improvement. Some patients get so much better with immuno-suppressive drugs that they dont need Mestinon® anymore.
      
      
   2. Can cramps and spasms be a side-effect, and are there treatments for them?
      
      Yes, they can be; if so, try cutting down the dose of Mestinon®. Another general treatment is quinine sulphate, but, if Mestinon® is to blame, that is a bit like swallowing a spider to catch a fly. There are other causes of cramps like over-tensing certain muscles for long periods. A very rare example is a (different) immune attack on the nerve endings - 'neuromyotonia' - which can be calmed down by drugs such as carbamazepine, or even treated by immunosuppression if need be.
      
      
   3. What can we do about loose bowels/ incontinence?
      
      Looseness can be a sign of bowel over-activity from taking too much Mestinon®. If so, one can cut down such effects on our 'automatic' functions with another drug called propantheline, or prevent the looseness with remedies for travellers' diarrhoea.
      
      
   4. Can Mestinon¨ affect asthma?
      
      In theory, it can, but that must be very rare. We advise patients to measure their peak flow before and after starting the drug (ie while blowing out).
   
   
6. Can patients with neither anti-MuSK nor anti-AChR antibodies still have generalised MG, and what is their outlook?
   
   Yes, they can; if so, diagnosis relies mainly on EMG. The anti-MuSK patients have only recently been recognised as a separate group; several teams now suspect that their MG is harder to control, whereas patients with neither antibody seem to respond better to immuno-suppressants. But we are still feeling our way, so watch this space.
   
   
7. If IvIg seems to work well, why not use that permanently?
   
   
   • IvIg is only a short-term measure - best used when you need a quick boost..
   • It doesn't get to the root of the trouble, so taking immuno-suppressants - to bring the immune attack under control - is neater and also simpler.
   • IvIg is a human product, pooled from thousands of apparently healthy donors. Though it is screened carefully, there is always the risk of some unknown or unsuspected infection lurking there, like hepatitis C, so one can't guarantee absolute safety.
   • The IvIg itself costs £1,000 each time, let alone the costs of being in hospital.
   
   
   
8. About Steroids
   
   
   1. If one goes too far when tapering down to the lowest working steroid dose, and starts to relapse, is it difficult to regain control?
      
      No, usually, a modest increase works well and a big jump-up is rarely needed. Such relapses seem less common when the tapering is done very slowly.
      
      
   2. Would either Mestinon® (pyridostigmine) or steroids upset control of Type 2 diabetes?
      
      No for Mestinon®, but, alas, yes for steroids. So patients may well need to be even more careful with their diet and take higher doses of their 'anti-diabetic' tablets than they otherwise would; some even need insulin injections to control their blood sugar. So that might be a good reason for using one of the 'second-line' immuno-suppressants like azathioprine, to help cut the steroid doses right down.
      
      
   3. Are there alternatives to steroids?
      
      Yes, there are several other immuno-suppressants like azathioprine, methotrexate, cyclosporin A and mycophenolate mofetil. Azathioprine takes many months to kick-in, but it quite clearly helps patients to 'cruise' on lower doses of steroids, with fewer side-effects.
      
      The others are less well tried-and-tested in MG, and are more powerfully immunosuppressive. So they act sooner, but probably carry greater risks of infections. They all have their own side-effects, and can affect fertility, and developing babies if taken by pregnant mums, whereas steroids and Azathioprine are generally accepted in the UK for use in pregnancy.
      
      
   4. Can steroids make MG worse?
      
      Only in the short-term and at high doses; otherwise, that is very rare - more likely that their side-effects are to blame.
   
   
   
9. Do the Side-effects of AZATHIOPRINE include:-
   
   
   1. skin tumours - Yes, patients on Azathioprine probably do get more benign ones (e.g. rodent ulcers, as well as warts), but they can easily be treated by local removal.
      
      
   2. lymphatic tumours (lymphomas) - that is highly debatable; at worst, they are rare.
      
      
   3. prostate cancer - No, there is no evidence of that at all.
      
      
   4. neuropathy - No, there is no evidence of that at all either
      
      
   5. anaemia - Yes. Normally, regular blood tests are done to check for side-effects on the liver as well as the red and white blood-forming cells in the bone marrow.
   
   One patient had done very well on steroids for years, but Azathioprine was added-in to help cut down their dose. Alas, that made him badly anaemic (blood count three times lower than normal). But, after he got back on the rails, he seemed to have fewer relapses than before!
   
   He asked:
   
   
   • "Could the anaemia have 're-booted' my immune system?"
     
     We can't think of an obvious mechanism; however, both the immune system and the bone marrow are so complicated that there might well be ripples that we aren't aware of. Usually, the likeliest explanation is the most boring one - i.e. that it's just coincidence.
     
     It's certainly a classic example of the best plans coming to grief.

MGA NEWS Summer 2004

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