What are common side effects of antibiotics?

The common side effects of antibiotics are primarily related to their impact on the body's natural microbiome, as well as their pharmacological properties. Nausea and diarrhea occur frequently because antibiotics can disrupt the balance of beneficial bacteria in the gut, leading to gastrointestinal disturbances. Moreover, allergic reactions can arise from the body's immunological response to the antibiotic; some individuals may develop skin rashes, itching, or more severe reactions such as anaphylaxis, depending on their sensitivity to specific antibiotic agents.

In contrast, the other options list side effects that are less commonly associated with antibiotics. Headaches, muscle pain, and insomnia may be associated with numerous medications but are not predominant side effects of antibiotic usage. Similarly, dry skin, hair loss, and constipation do not have strong correlations with antibiotic treatment. Lastly, weight gain, increased thirst, and fatigue are more often linked to other categories of medications or underlying health issues rather than the effects of antibiotics on the body. Thus, the recognition of nausea, diarrhea, and allergic reactions as the common side effects highlights the distinctive side effects typically observed in patients undergoing antibiotic therapy.