QUESTION What are the side effects of quinine? ANSWER The main side effect of quinine, in therapeutic doses, is cinchonism or quinism. This is a condition associated with a number of symptoms, including flushed/sweaty skin, tinnitus, confusion, headaches, and more. Mild cinchonism should not be a reason to cease treatment with quinine, however. If injected into a nerve, quinine can … [Read more...]