Quinine Poisoning

Letter to the Editor.

IN your November issue reference is made to the effect of the excessive use of quinine.

The principal effect of quinine upon the eyes of those whose toleration for the drug is not good consists in a concentric contraction of the visual field of vision, without as a rule any marked diminution of colour values, save in some cases a tendency to xanthopsia, or seeing an ex cess of yellow. Other effects of quinine poisoning (or cinchonism, as it is called) are tinnitus (singing in the ear), vertigo (dizziness), etc. Quinine amblyopia (dimness of vision) is due to the reduced action of the heart and lowered arterial tension, which the drug causes. Cessa tion of its use and general tonic treatment usually produces a speedy improvement.

Large doses of quinine are dangerous to sight, and have been known to cause ab solute blindness if persisted in. In order to avoid any possibility of harm the ad vice of a medical practitioner should be obtained.

I am, etc.,

L. L. Bell

Optometrist and Optician.

Sydney, 28/11/34.