Commonly reported side effects of ivermectin include: fever, pruritus, and skin rash. See below for a comprehensive list of adverse effects. For the Consumer. Applies to ivermectin: oral tablet. Along with its needed effects, ivermectin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Check with your doctor as soon as possible if any of the following side effects occur while taking ivermectin: Less common—for the treatment of river blindness (onchocerciasis) only. Eye or eyelid irritation, pain, redness, or swelling; Some side effects of ivermectin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.