A decreased appetite is when you have a reduced desire to eat. The medical term for a loss of appetite is anorexia. Hyperthyroidism should be considered as well (ususally with increased appatite). Some type of infection is another common cause of weight loss with low appetite. The most common side effects of antibiotics affect the digestive system. These occur in around 1 in 10 people. Learn about the potential side effects of erythromycin. Includes common and rare side effects information for consumers and healthcare professionals. This Site Might Help You. RE: loss of appetite on antibiotics? I& 39;m on day 9 on a 14 day course treatment for an h.pylori infections. I& 39;m 26 and. There are a number of antibiotics that can cause changes in taste (dysgeusia) or decease/loss of taste (hypothesis/ageusia) including fluoroquinolones (levofloxacin. Doctors give trusted, helpful answers on causes, diagnosis, symptoms, treatment, and more: Dr. Beck on antibiotics loss of appetite: May be a side effect of the drug. Can Erythromycin cause Loss of Appetite? Complete analysis from patient reviews and trusted online health resources, including first-hand experiences. Find patient medical information for erythromycin oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. GASTROPARESIS TREATMENT ERYTHROMYCIN ] The REAL cause of Diabetes (and the solution) Skip to content. diabetes type 1 loss of appetite Read More;.