What Side Effects Are Caused By Drinking Quinine With Tonic Water?

my question is: would drinking tonic water (contains quinine) have any affect on causing side-affects or is the amount of quinine in tonic water too small to have an affect. I find that drinking tonic water helps me to sleep and cuts down on the number of times I have to get up in the night. I am 84 years old and usually in excellent health. The eye pressure is up because of a monthly shot in one eye for macular degeneration control, so the glaucoma now needs attention. Now I am very light-headed during the day to the point of feeling dizzy, but not so dizzy as to fall. I am going to my own GP later today so looked up DuoTrav side affects to take to the appointment.