Please note that "drugs that appear to protect the nerves from damage" may well act against undetected infectious agents. I have previously noted that
fluoxetine strongly inhibits Coxsackie B virus. This now appears to extend to
a wider class of enteroviruses. (This is probably also true for a range of SSRIs. It is still too early to say if SNRIs have effects on viruses.)
While amiloride is approved for use in heart disease, particularly when there is hypertension, as a potassium-sparing diuretic it may well have off-label use in channelopathies exacerbated by hypokalemia. It may also be useful in hypomagnesemia. It has repeatedly been used to treat polyuria in patients on lithium salts. Does it have an effect on infectious agents? I don't know, but I do know that lithium levels do affect viral loads of HIV. Other electrolytes may also have effects on viral replication. Many bacteria are sensitive to potassium levels. To what extent this effect in humans is due to
direct activity of ions on bacteria or
to inflammatory response remains to be seen.
Exactly how riluzole extends survival by months in ALS is not clear. It is known to block specific kinds of sodium channels, as well as receptors to kainate and NMDA. Exactly what it does to glutamate receptors remains controversial.
Please note that all these drugs act on receptors for either neurotransmitters or electrolytes. These receptors have effects on many immune cells, and some directly affect either bacteria or immune response to them. These drugs all show up in psychopharmacology literature, which suggests to me that undiagnosed neurological disease may well be behind common psychiatric illnesses.
