As with everything....small amounts. Like one drink. Not all day. Most of the side effects are with the oral meducation prescribed for malaria. I believe you'd need to drink 2 litres of tonic water to reach those levels ...which I guess some people could do.
Magnesium shouldn't be taken with thyroxine if you are on that. At least 4 hours apart as it blocks is effectiveness.
My brother has a tonic water at night which he did find helps the side effects of cramps with statins. No guarantees of course.