What could be a sign of an adverse reaction to an antibiotic?

Nausea is a common and well-documented sign of an adverse reaction to antibiotics. Many antibiotics can disrupt the normal balance of bacteria in the gut or irritate the gastrointestinal tract, leading to symptoms such as nausea, vomiting, or diarrhea. This reaction occurs as the body responds to the medication, and while nausea may not occur in every individual taking an antibiotic, it is a recognized side effect that healthcare providers monitor.

In contrast to nausea, feelings of euphoria and increased energy are not commonly associated with antibiotics. They may suggest other factors at play, such as psychological effects or possible underlying conditions, rather than a direct result of the medication. Similarly, weight gain is not a typical reaction to antibiotics; weight changes can occur for a variety of reasons that are not necessarily related to the immediate effect of the medication.