Of course I saw my Doctor, and we must all be cautious of conditions esp when in our Seventies.
He confirmed that it was the Quinine that was helping. I now drink about 3 litres a week.
Of interest here re cramps:
http://www.nhs.uk/Conditions/legcrampsunknowncause/Pages/Introduction.aspxOne in three over 60's get leg cramps. No further medical action was needed in my case. If in doubt, see your G.P.